diff --git "a/raw_rss_feeds/https___arxiv_org_rss_astro_ph.xml" "b/raw_rss_feeds/https___arxiv_org_rss_astro_ph.xml" --- "a/raw_rss_feeds/https___arxiv_org_rss_astro_ph.xml" +++ "b/raw_rss_feeds/https___arxiv_org_rss_astro_ph.xml" @@ -7,2229 +7,2008 @@ http://www.rssboard.org/rss-specification en-us - Wed, 10 Dec 2025 05:00:24 +0000 + Thu, 11 Dec 2025 05:00:10 +0000 rss-help@arxiv.org - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 Saturday Sunday - Solar neutron and muon detection on November 11, 2025: First simultaneous recovery of energy spectra - https://arxiv.org/abs/2512.07859 - arXiv:2512.07859v1 Announce Type: new -Abstract: Ground Level Enhancement (GLE) events provide rare opportunities to study high-energy solar particle acceleration through direct detection of secondary radiation at ground level. On November 11, 2025, the Aragats Solar Neutron Telescope (ASNT) recorded a statistically significant increase in high-energy neutron and muon fluxes associated with an X5.1 flare and the subsequent Solar Energetic Proton (SEP) event. The event displayed a unique dual-peak profile: an initial hard component at 10 28 UT, followed by a softer yet still energetic peak at 10 45 UT. For the first time, we report simultaneous energy spectra of atmospheric neutrons and muons measured in the 10 600 MeV range at Aragats. Broken-power-law fits reveal a clear temporal evolution of acceleration conditions, evidenced by spectral indices declining with energy. These findings highlight the unique capabilities of the ASNT as an instrument for studying extreme solar particle acceleration. - oai:arXiv.org:2512.07859v1 - astro-ph.SR - physics.ao-ph - physics.space-ph - Wed, 10 Dec 2025 00:00:00 -0500 + Probing jet base emission of M87* with the 2021 Event Horizon Telescope observations + https://arxiv.org/abs/2512.08970 + arXiv:2512.08970v1 Announce Type: new +Abstract: We investigate the presence and spatial characteristics of the jet base emission in M87* at 230 GHz, enabled by the enhanced uv coverage in the 2021 Event Horizon Telescope (EHT) observations. The addition of the 12-m Kitt Peak Telescope and NOEMA provides two key intermediate-length baselines to SMT and the IRAM 30-m, giving sensitivity to emission structures at scales of $\sim250~\mu$as and $\sim2500~\mu$as (0.02 pc and 0.2 pc). Without these baselines, earlier EHT observations lacked the capability to constrain emission on large scales, where a "missing flux" of order $\sim1$ Jy is expected. To probe these scales, we analyzed closure phases, robust against station-based gain errors, and modeled the jet base emission using a simple Gaussian offset from the compact ring emission at separations $>100~\mu$as. Our analysis reveals a Gaussian feature centered at ($\Delta$RA $\approx320~\mu$as, $\Delta$Dec $\approx60~\mu$as), a projected separation of $\approx5500$ AU, with a flux density of only $\sim60$ mJy, implying that most of the missing flux in previous studies must arise from larger scales. Brighter emission at these scales is ruled out, and the data do not favor more complex models. This component aligns with the inferred direction of the large-scale jet and is consistent with emission from the jet base. While our findings indicate detectable jet base emission at 230 GHz, coverage from only two intermediate baselines limits reconstruction of its morphology. We therefore treat the recovered Gaussian as an upper limit on the jet base flux density. Future EHT observations with expanded intermediate-baseline coverage will be essential to constrain the structure and nature of this component. + oai:arXiv.org:2512.08970v1 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - A. Chilingarian, B. Sargsyan, L. Kozliner, T. Karapetyan + Saurabh, Hendrik M\"uller, Sebastiano D. von Fellenberg, Paul Tiede, Michael Janssen, Lindy Blackburn, Avery E. Broderick, Erandi Chavez, Boris Georgiev, Thomas P. Krichbaum, Kotaro Moriyama, Dhanya G. Nair, Iniyan Natarajan, Jongho Park, Andrew Thomas West, Maciek Wielgus, Kazunori Akiyama, Ezequiel Albentosa-Ru\'iz, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Balokovi\'c, Bidisha Bandyopadhyay, John Barrett, Michi Baub\"ock, Bradford A. Benson, Dan Bintley, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Michael Bremer, Roger Brissenden, Silke Britzen, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, Douglas F. Carlos, John E. Carlstrom, Andrew Chael, Chi-kwan Chan, Dominic O. Chang, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Paul Chichura, Ilje Cho, Pierre Christian, Nicholas S. Conroy, John E. Conway, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Brandon Curd, Rohan Dahale, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Gregory Desvignes, Jason Dexter, Vedant Dhruv, Indu K. Dihingia, Sheperd S. Doeleman, Sergio A. Dzib, Ralph P. Eatough, Razieh Emami, Heino Falcke, Joseph Farah, Vincent L. Fish, Edward Fomalont, H. Alyson Ford, Marianna Foschi, Raquel Fraga-Encinas, William T. Freeman, Per Friberg, Christian M. Fromm, Antonio Fuentes, Peter Galison, Charles F. Gammie, Roberto Garc\'ia, Olivier Gentaz, Ciriaco Goddi, Roman Gold, Arturo I. G\'omez-Ruiz, Jos\'e L. G\'omez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Ronald Hesper, Dirk Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Britton Jeter, Wu Jiang, Alejandra Jim\'enez-Rosales, Michael D. Johnson, Svetlana Jorstad, Adam C. Jones, Abhishek V. Joshi, Taehyun Jung, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Joana A. Kramer, Michael Kramer, Cheng-Yu Kuo, Noemi La Bella, Deokhyeong Lee, Sang-Sung Lee, Aviad Levis, Shaoliang Li, Zhiyuan Li, Rocco Lico, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Amy E. Lowitz, Ru-Sen Lu, Nicholas R. MacDonald, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Iv\'an Mart\'i-Vidal, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Hugo Messias, Izumi Mizuno, Yosuke Mizuno, Joshua Montgomery, James M. Moran, Monika Moscibrodzka, Wanga Mulaudzi, Cornelia M\"uller, Alejandro Mus, Gibwa Musoke, Ioannis Myserlis, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Gopal Narayanan, Antonios Nathanail, Santiago Navarro Fuentes, Joey Neilsen, Chunchong Ni, Michael A. Nowak, Junghwan Oh, Hiroki Okino, H\'ector Ra\'ul Olivares S\'anchez, Tomoaki Oyama, Feryal \"Ozel, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Pi\'etu, Alexander Plavin, Aleksandar PopStefanija, Oliver Porth, Ben Prather, Giacomo Principe, Dimitrios Psaltis, Hung-Yi Pu, Alexandra Rahlin, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Luciano Rezzolla, Angelo Ricarte, Luca Ricci, Bart Ripperda, Jan R\"oder, Freek Roelofs, Cristina Romero-Ca\~nizales, Eduardo Ros, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Le\'on D. S. Salas, Salvador S\'anchez, David S\'anchez-Arg\"uelles, Miguel S\'anchez-Portal, Mahito Sasada, Kaushik Satapathy, Tuomas Savolainen, F. Peter Schloerb, Jonathan Schonfeld, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Sasikumar Silpa, Des Small, Randall Smith, Bong Won Sohn, Jason SooHoo, Kamal Souccar, Joshua S. Stanway, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Remo P. J. Tilanus, Michael Titus, Kenji Toma, Pablo Torne, Teresa Toscano, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jasmin E. Washington, Jonathan Weintroub, Robert Wharton, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, George N. Wong, Jompoj Wongphexhauxsorn, Qingwen Wu, Nitika Yadlapalli, Paul Yamaguchi, Aristomenis Yfantis, Doosoo Yoon, Andr\'e Young, Ziri Younsi, Wei Yu, Feng Yuan, Ye-Fei Yuan, Ai-Ling Zeng, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao - SATMO: a Multi-Planet Thermal Analysis Tool for CubeSat Missions - https://arxiv.org/abs/2512.07896 - arXiv:2512.07896v1 Announce Type: new -Abstract: The expansion of commercial launch capabilities has significantly increased opportunities for interplanetary small satellite (SmallSat) missions. As researchers plan for more missions beyond Earth, there is a demand for accessible tools that help better predict and understand the thermal effects on their spacecraft in orbital environments around Earth and other bodies. While commercial thermal analysis tools offer high-fidelity modeling capabilities and results, they are often expensive and require extensive training to be used effectively. This paper details a framework for a user-friendly Satellite Thermal Model (SATMO) to support the early stages of space mission planning for CubeSats orbiting Earth and other Solar System bodies. SATMO is an open-source, MATLAB-based, six-node thermal analysis program designed for satellites in low-altitude circular orbits. Although SATMO requires a MATLAB license -- typically inexpensive or institutionally provided in academic settings -- it remains substantially more accessible than professional thermal analysis software. SATMO requires an internet connection for some features but does not rely on additional MATLAB toolboxes. The SATMO modeling approach is validated with the space industry standard Thermal Desktop software, with temperatures comparable to within 1.17$^\circ$C for a 10 cm $\times$ 10 cm $\times$ 10 cm CubeSat in various configurations, orbiting around primary bodies including Earth, Venus, and Mars. An example use case of SATMO is presented with a Mars-orbiting CubeSat to demonstrate its functionalities and the outputs available to users. SATMO offers increased accessibility to satellite thermal modeling for the research community, enabling quick thermal trade studies and interplanetary mission plans. - oai:arXiv.org:2512.07896v1 - astro-ph.IM - physics.app-ph - Wed, 10 Dec 2025 00:00:00 -0500 + Kinematics and physical structure of Ou 5: A bipolar planetary nebula with extreme abundance discrepancy and an eclipsing binary core + https://arxiv.org/abs/2512.09012 + arXiv:2512.09012v1 Announce Type: new +Abstract: We present new deep imaging and high-resolution spectroscopy of the extreme-abundance-discrepancy planetary nebula Ou 5, together with photoionization modelling aimed at probing its unusual thermal and chemical structure. The nebula exhibits a nested bipolar morphology, including inner and outer shells, faint outer lobes, and polar knots. Remarkably, all these components share a dynamical age of order 10,000 yr. Thermal broadening of the H alpha line relative to heavier ions implies a hydrogen temperature 3000 K to 6000 K, in contrast to the ~ 10,000 K derived from collisionally excited line diagnostics. This provides independent support for the presence of at least two distinct temperature/metallicity phases, as previously proposed to explain extreme abundance discrepancies. Photoionization models with sinusoidally varying metallicity successfully reproduce the observed nebular spectrum and morphology. A mixture of fluctuations with both extreme and moderate metallicity contrasts is required to simultaneously fit the O II and the [O III] observations. The nebular He II emission demands a hotter and more luminous central star than previously inferred, consistent with a ~ 0.58 solar mass post-AGB progenitor evolving toward a CO white dwarf. Ou 5 thus reinforces the link between close-binary nuclei and extreme abundance discrepancies, and provides a valuable benchmark for understanding how common-envelope ejections give rise to the thermal and abundance inhomogeneities observed in planetary nebulae. + oai:arXiv.org:2512.09012v1 + astro-ph.GA + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Alexander Chipps, Daniel Forgette, Kerri Cahoy + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + William J. Henney (Instituto de Radioastronom\'ia y Astrof\'isica, UNAM, Morelia, Mexico), J. A. L\'opez (Instituto de Astronom\'ia, UNAM, Ensenada, Mexico), Ma. T. Garc\'ia-D\'iaz (Instituto de Astronom\'ia, UNAM, Ensenada, Mexico), M. G. Richer (Instituto de Astronom\'ia, UNAM, Ensenada, Mexico), D. H. Gonz\'alez-Buitrago (Instituto de Astronom\'ia, UNAM, Ensenada, Mexico), S. V. Zharikov (Instituto de Astronom\'ia, UNAM, Ensenada, Mexico), S. Noroozi (Constructor University, Bremen, Germany), F. Pozo Nu\~nez (Heidelberg Institute for Theoretical Studies, Heidelberg, Germany) - The interstellar signature: A computational framework for open source interstellar tracking - https://arxiv.org/abs/2512.07910 - arXiv:2512.07910v1 Announce Type: new -Abstract: Interstellar objects such as 1I/'Oumuamua and 2I/Borisov offer a unique window into the formation and evolution of other star systems, yet the tracking and analysis of their trajectories remain limited to specialized research institutions. Existing interstellar and solar system datasets are large, complex, and difficult to navigate, reducing accessibility for developers, researchers, and enthusiasts. To address this, we present The Interstellar Signature: a computational framework for open-source interstellar tracking, implemented through a web-based platform. - Interstellar Signature bridges raw astronomical data and an intuitive, developer-friendly interface. The framework integrates live data streams from public repositories and APIs with physics-based simulation methods to model and visualize the motion of interstellar and solar system objects in real time. The platform supports interactive visualizations, comparative orbital analysis, and modular tools that allow users to explore and extend the system for research, experimentation, or development. - As an open-source project, the framework encourages collaboration and hands-on engagement with complex datasets. It exists within NexusCosmos, an ecosystem envisioned as a "Linux for the space race," aimed at democratizing access to space science tools and data. By transforming large datasets into visual, interactive, and customizable simulations, Interstellar Signature expands participation in interstellar research and observation. - Future extensions will add AI-driven trajectory prediction, anomaly detection, and advanced visualization. By combining open-source accessibility with computational rigor, this framework lowers the barrier to interstellar analysis and serves as a step toward bridging professional astronomy and public scientific engagement. - oai:arXiv.org:2512.07910v1 - astro-ph.IM - astro-ph.EP - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Viscously Spreading Accretion Disks around Black Holes: Implications for TDEs, LFBOTs and other Transients + https://arxiv.org/abs/2512.09017 + arXiv:2512.09017v1 Announce Type: new +Abstract: We present a simple time-dependent model of viscously spreading accretion disks around black holes (BHs) with masses between $10-10^8M_\odot$. We apply the results to observations of late-time emission in tidal disruption events (TDEs) and luminous fast blue optical transients (LFBOT) such as AT2018cow. Our model generalizes previous work by incorporating outflows during super-Eddington accretion, non-conservation of mass and angular momentum in TDE circularization, irradiation of the outer disk by the inner accretion flow, and a range of viscous stress models. We show that many late-time plateaus in TDEs can be explained by disks formed with a large spread in angular momentum due to redistribution during circularization. Viscous spreading on year timescales is not required, although it is also compatible with the data. The collapse of radiation pressure dominated thin disks to the stable gas-pressure dominated phase greatly underpredicts TDE plateau luminosities, strongly favoring thermally stable magnetically dominated disk models. Irradiation of the outer disk in TDEs due to misalignment of the stellar orbit and black hole spin increases plateau luminosities and durations by factors of a few. Continued study of late-time TDE emission provides a unique opportunity to constrain the physics of disk formation and circularization, disk warps, angular momentum transport, and other poorly understood aspects of disk physics. The models we develop can also explain the late-time optical-UV emission in the LFBOT AT2018cow for BH masses of ~$10-100M_\odot$. The faint X-ray emission at late times in AT2018cow is likely due to ongoing absorption. Our models predict that late-time X-rays should eventually be detectable again, and that HST/JWST observations of AT2018cow may detect a break in the SED at near-IR-optical wavelengths, providing a powerful probe of outer accretion disk thermodynamics. + oai:arXiv.org:2512.09017v1 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Pancha Narayan Sahu + Mila Winter-Granic, Eliot Quataert - Microlensing Signatures of Dyson Sphere-like Structures around Primordial Black Holes as Technosignatures of Extraterrestrial Advanced Civilizations - https://arxiv.org/abs/2512.07924 - arXiv:2512.07924v1 Announce Type: new -Abstract: We investigate the microlensing detectability of extraterrestrial technosignatures originating from Dyson sphere \textendash like structures, such as Dyson Swarms surrounding primordial black holes (PBHs). These hypothetical swarms consist of stochastically varying, partially opaque structures that could modulate standard microlensing light curves through time-dependent transmission effects. We introduce a probabilistic framework that includes a stochastic transmission model governed by variable optical depth and random gap distributions. We perform a parameter scan and generate heatmaps of the optical transit duration. We study the infrared excess radiation and peak emission wavelength as complementary observational signatures. Additionally, we define and analyze the effective optical depth and the anomalous microlensing event rate for these stochastic structures. Our findings provide a new avenue for searching for extraterrestrial advanced civilizations by extending microlensing studies to include artificial, dynamic modulation signatures. - oai:arXiv.org:2512.07924v1 - astro-ph.IM - astro-ph.CO + University of Hawaii 88-inch Telescope Observations of the Interstellar Comet 3I/ATLAS: Spectrophotometric Blue-Sensitive Spectral Time Series Spanning Two Months from Discovery + https://arxiv.org/abs/2512.09020 + arXiv:2512.09020v1 Announce Type: new +Abstract: Interstellar objects are the ejected building blocks of other solar systems. As such, they enable the acquisition of otherwise inaccessible information about nascent extrasolar systems. The discovery of the third interstellar object, 3I/ATLAS, provides an opportunity to explore the properties of a small body from another solar system and to compare it to the small bodies in our own. To that end, we present spectrophotometric observations of 3I/ATLAS taken using the SuperNova Integral Field Spectrograph on the University of Hawaii 2.2-m telescope. Our data includes the earliest $\lambda\leq3800$ A spectrum of 3I/ATLAS, obtained $\sim$12.5 hours after the discovery announcement. Later spectra confirm previously reported cometary activity, including Ni and CN emission. The data show wavelength-varying spectral slopes ($S\approx($0\%-29\%)/1000 A, depending on wavelength range) throughout the pre-perihelion ($r_h=4.4$-$2.5$ au) approach of 3I/ATLAS. We perform synthetic photometry on our spectra and find 3I/ATLAS shows mostly stable color evolution over the period of our observations, with $g-r$ colors ranging from $\sim$0.69-0.75 mag, $r-i$ colors ranging from $\sim$0.26-0.30 mag, and $c-o$ colors ranging from $\sim$0.50-0.55 mag. Ongoing post-perihelion observations of 3I/ATLAS will provide further insight into its potentially extreme composition. + oai:arXiv.org:2512.09020v1 astro-ph.EP - physics.pop-ph - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Shant Baghram + W. B. Hoogendam, D. Kuesters, B. J. Shappee, G. Aldering, J. J. Wray, B. Yang, K. J. Meech, M. A. Tucker, M. E. Huber, K. Auchettl, C. R. Angus, D. D. Desai, J. T. Hinkle, J. Kiyokawa, G. S. H. Paek, S. Romagnoli, J. Shi, A. Syncatto, C. Ashall, M. Dixon, K. Hart, A. M. Hoffman, D. O. Jones, K. Medler, C. Pfeffer - Evidence for evolving Dark Energy from a new cosmic probe - https://arxiv.org/abs/2512.07931 - arXiv:2512.07931v1 Announce Type: new -Abstract: The $\Lambda$CDM concordance cosmological model provides a remarkably successful description of the formation and evolution of structure in the Universe. However, a growing discrepancy between measurements of the expansion rate $H_0$ from the near and distant Universe now appears to be significant at the ~4-7 $\sigma$ level. This inconsistency, known as the ``Hubble tension'', has arisen either due to unrecognized systematics in these measurements or new physics beyond the standard model, such as an evolving dark energy equation of state. Modeling ~20-year, multi-band optical light curves for 6992 active galactic nuclei (AGN), we find a tight relation linking the variability amplitude and characteristic timescale to their intrinsic luminosity. This empirical law enables us to construct an AGN-based Hubble diagram to z ~3.5. Joint inference with supernova distances reveals evidence for an evolving dark energy equation of state at the 3.8-3.9 $\sigma$ level over constant w models and 4.4-4.8 $\sigma$ over $\Lambda$CDM. Our results establish AGN light curves as a powerful tool for cosmography that could offer a novel pathway to test deviations from the standard $\Lambda$CDM expansion history. - oai:arXiv.org:2512.07931v1 + Interpretable machine learning of halo gas density profiles: a sensitivity analysis of cosmological hydrodynamical simulations + https://arxiv.org/abs/2512.09021 + arXiv:2512.09021v1 Announce Type: new +Abstract: Stellar and AGN-driven feedback processes affect the distribution of gas on a wide range of scales, from within galaxies well into the intergalactic medium. Yet, it remains unclear how feedback, through its connection to key galaxy properties, shapes the radial gas density profile in the host halo. We tackle this question using suites of the EAGLE, IllustrisTNG, and Simba cosmological hydrodynamical simulations, which span a variety of feedback models. We develop a random forest algorithm that predicts the radial gas density profile within haloes from the total halo mass and five global properties of the central galaxy: gas and stellar mass; star formation rate; mass and accretion rate of the central black hole (BH). The algorithm reproduces the simulated gas density profiles with an average accuracy of $\sim$80-90% over the halo mass range $10^{9.5} \, \mathrm{M}_{\odot} < M_{\rm 200c} < 10^{15} \, \mathrm{M}_{\odot}$ and redshift interval $0<z<4$. For the first time, we apply Sobol statistical sensitivity analysis to full cosmological hydrodynamical simulations, quantifying how each feature affects the gas density as a function of distance from the halo centre. Across all simulations and redshifts, the total halo mass and the gas mass of the central galaxy are the most strongly tied to the halo gas distribution, while stellar and BH properties are generally less informative. The exact relative importance of the different features depends on the feedback scenario and redshift. Our framework can be readily embedded in semi-analytic models of galaxy formation to incorporate halo gas density profiles consistent with different hydrodynamical simulations. Our work also provides a proof of concept for constraining feedback models with future observations of galaxy properties and of the surrounding gas distribution. + oai:arXiv.org:2512.09021v1 + astro-ph.GA astro-ph.CO - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + cs.LG + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Isaque Dutra, Colin J. Burke, Priyamvada Natarajan, Weixiang Yu + http://creativecommons.org/licenses/by/4.0/ + Daniele Sorini, Sownak Bose, Mathilda Denison, Romeel Dav\'e - Probing the Warm Dark Matter mass with [C II] intensity mapping - https://arxiv.org/abs/2512.07933 - arXiv:2512.07933v1 Announce Type: new -Abstract: The nature of dark matter (DM) is still debated. While cold DM (CDM) is the standard paradigm, warm DM (WDM) may ease some small-scale tensions in the $\Lambda$CDM framework. Line-intensity mapping (LIM) offers a novel probe of DM properties. To explore the potential of LIM surveys in constraining the WDM particle mass ($m_\mathrm{WDM}$) by means of the [C II] power spectrum (PS), we provide forecasts for the Deep Spectroscopic Survey (DSS) at $z\simeq3.6$ and extend the analysis to larger sky coverage, higher sensitivity, and/or increased spectral resolution. We develop a formulation for the [C II] PS based on the halo-model approach, incorporating the uncertainty in the luminosity function (LF) through two alternative parameterisations. We perform a Bayesian analysis on mock data to derive constraints on $m_\mathrm{WDM}$. In a CDM universe, the DSS yields lower limits on $m_\mathrm{WDM}$ at $95\%$ credibility level (CL) of $1.10$ keV and $0.58$ keV when considering the optimistic and pessimistic LF ($\alpha = -1.1$), respectively. Ambitious surveys can improve these figures to $5.82$ keV and $1.90$ keV, and assuming a steeper faint-end slope ($\alpha = -1.9$) further boosts these limits. A fivefold increase in spectral resolution enhances sensitivity to the damping scale associated to redshift-space distortions, tightening the constraints on $m_\mathrm{WDM}$ by a factor of up to $\sim1.8$. Finally, Bayesian inference on mock data with $m_\mathrm{WDM}=3$ keV results in a well-constrained and unbiased posterior only in futuristic survey setups. Upcoming LIM surveys can provide meaningful limits on $m_\mathrm{WDM}$, although the negligible contribution from small haloes reduces the constraining power of the [C II] PS. Future progress will benefit from combining multiple redshifts and emission lines, opening the way to competitive constraints on the nature of DM. - oai:arXiv.org:2512.07933v1 - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + GA-NIFS: Understanding the ionization nature of EGSY8p7/CEERS-1019. Evidence for a star formation-driven outflow at z = 8.6 + https://arxiv.org/abs/2512.09022 + arXiv:2512.09022v1 Announce Type: new +Abstract: Understanding the physical conditions and feedback mechanisms in early massive galaxies is essential to uncover how they formed and evolved during the first billion years of the Universe. In this context, the galaxy EGSY8p7/CEERS-1019 at z=8.6 provides an excellent benchmark, given its stellar mass of $10^{9.3}M_\odot$ and elevated N/O abundance despite its sub-solar metallicity. In this study, we present new JWST/NIRSpec observations offering the first spatially resolved spectroscopy of this galaxy, with higher sensitivity and spectral resolution than previous studies. We identify broad (FWHM=650km/s) H$\beta$ and [OIII] emission components whose emission is located between the two rest-frame UV clumps of the galaxy and extended over a distance of $\sim1kpc$. The morphology and kinematics of these components indicate that the broad emission arises from outflowing gas rather than from an AGN broad-line region. The kinetic energy injection rate from stellar feedback is an order of magnitude higher than that of the outflow, while the radiation pressure rate is comparable to the outflow momentum rate. These results suggest that stellar feedback alone can drive the outflow, with radiation pressure potentially providing the required momentum transfer. We derive a low mass-loading factor ($\eta=0.16$) and ionizing photon escape fraction ($f_{esc}=0.021\pm0.014$). Together with the high electron density measured ($n_e=2200cm^{-3}$), these results support the interpretation that most of the gas remains confined within the galaxy. Comparisons of diagnostic emission-line ratios with photoionization and shock models support a star-formation-driven ionization scenario, ruling out any excitation by AGN radiation. Finally, the absence of detectable Wolf-Rayet features suggests that alternative mechanisms must be considered to explain the high N/O ratio in this galaxy. + oai:arXiv.org:2512.09022v1 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Elena Marcuzzo, Cristiano Porciani, Emilio Romano-D\'iaz, Azadeh Moradinezhad Dizgah, Prachi Khatri, Matteo Viel + http://creativecommons.org/licenses/by/4.0/ + Sandra Zamora, Stefano Carniani, Elena Bertola, Eleonora Parlanti, Pablo G. P\'erez-Gonz\'alez, Santiago Arribas, Torsten B\"oker, Andrew J. Bunker, Francesco D'Eugenio, Roberto Maiolino, Michele Perna, Bruno Rodr\'iguez Del Pino, Hannah \"Ubler, Giovanni Cresci, Gareth C. Jones, Isabella Lamperti, Jan Scholtz, Bartolomeo Trefoloni, Giacomo Venturi - Detection of 27 Candidate Circumbinary Planets Through Apsidal Precession of Eclipsing Binaries Observed by TESS - https://arxiv.org/abs/2512.07934 - arXiv:2512.07934v1 Announce Type: new -Abstract: Most circumbinary planets have been discovered by their transits, limiting our understanding of such systems to those with mutually coplanar architectures. This bias makes it difficult to infer the true circumbinary planet population, highlighting the need for alternative detection methods that do not rely on transits. In this work, we explore one such approach by leveraging apsidal precession as a dynamical signature of planetary companions. We analyse TESS photometry of a sample of 1,590 eclipsing binaries from the Gaia DR3 Catalogue of Eclipsing Binary Candidates to identify systems exhibiting detectable apsidal precession. We rule general relativistic, tidal, and rotational contributions as insufficient to account for the measured apsidal precession, demonstrating that an additional gravitational perturber is required. This enables us to constrain the possible masses and orbital separations of a companion that would cause the observed precession. We present a new set of 27 candidate circumbinary planets identified through this precession-based method as well as 6 candidate companions with a higher minimum mass. Their inferred properties remain degenerate, as the same dynamical signatures can arise from lower-mass planets at less than 1 AU or from more massive companions on wider, few-AU orbits, reflecting the current uncertainty in characterising these systems. Radial velocities can help break this degeneracy and provide direct confirmation. - oai:arXiv.org:2512.07934v1 - astro-ph.EP - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + The eventful life journey of galaxy clusters. II. Impact of mass accretion on the thermodynamical structure of the ICM + https://arxiv.org/abs/2512.09023 + arXiv:2512.09023v1 Announce Type: new +Abstract: Context. The internal structure of the intracluster medium (ICM) is tightly linked to the assembly history and physical processes in groups and clusters, but the role of recent accretion in shaping these profiles has not been fully explored. + Aims. We investigate to what extent mass accretion accounts for the variability in ICM density and thermodynamic profiles, and what can present-day structures reveal about their formation histories. + Methods. We analyze a hydrodynamical cosmological simulation including gas cooling but no feedback, to isolate the effects of heating from structure formation. Median profiles of ICM quantities are introduced as a robust description of the bulk ICM. We then examine correlations between mass accretion rates or assembly indicators with the profiles of temperature, entropy, pressure, gas and dark-matter density, as well as their scatter. + Results. Accretion in the last dynamical time strongly lowers central gas densities, while leaving dark matter largely unaffected, producing a distinct signature in the baryon depletion function. Pressure and entropy show the clearest dependence on accretion, whereas temperature is less sensitive. The radii of steepest entropy, temperature, and pressure shift inward by $\sim (10-20)\%$ between high- and low-accretion subsamples. Assembly-state indicators are also related to the location of these features, and accretion correlates with the parameters of common fitting functions for density, pressure, and entropy. + Conclusions. Recent accretion leaves measurable imprints on the ICM structure, highlighting the potential of thermodynamic profiles as diagnostics of cluster growth history. + oai:arXiv.org:2512.09023v1 + astro-ph.CO + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Margo Thornton, Benjamin T. Montet, Riley White, Arden Shao, Diya T. Kumar + David Vall\'es-P\'erez, Susana Planelles, Vicent Quilis - On the Type IIn SN 2025cbj coincidence with the high-energy neutrino IceCube-250421A - https://arxiv.org/abs/2512.07936 - arXiv:2512.07936v1 Announce Type: new -Abstract: Context. The origin of the astrophysical high-energy neutrino flux remains uncertain. Core-collapse supernovae with strong CSM interaction (Type IIn) are compelling candidates for efficient hadronic acceleration and neutrino production. Aims. We investigate the possible association between the Type IIn supernova SN2025cbj and the IceCube high-energy neutrino IceCube-250421A, and assess whether the observed properties of the SN permit an appreciable neutrino yield. Methods. We combined rapid optical follow-up with LAST and archival ZTF photometry with spectroscopy from LT/SPRAT and MMT/BINOSPEC to characterize the SN evolution and CSM interaction. We estimated the explosion and peak times from early light-curve fitting, and quantified the chance-coincidence probability with resampling simulations that scramble neutrino right ascensions while preserving declinations and error contours. Using a simple post-shock-breakout interaction model in a dense wind, we estimated the expected muon-neutrino yield for IceCube real-time Bronze stream. Results. Spectra of SN2025cbj obtained after the neutrino epoch show persistent narrow Balmer lines superposed on broad Lorentzian electron-scattering wings, consistent with sustained dense-CSM interaction. For the multi-messenger association, resampling simulations against the TNS catalog give a chance-coincidence probability for observing $k \ge 1$ events of $p \simeq 0.24$ (and $p \simeq 0.078$ against the ZTF-BTS catalog). These values are sensitive to the size of the SNe and neutrino samples. A post-breakout interaction scenario predicts an expected $N_{\nu_\mu} \sim 10^{-3}$ events in the IceCube Bronze alert stream over 76 days per this one candidate. We discuss the implications of these numbers and possible biases that may affect these results. - oai:arXiv.org:2512.07936v1 + Non-Equilibrium Thermodynamics of Black-Hole Coronae: QPOs, Turbulence, and Jets + https://arxiv.org/abs/2512.09026 + arXiv:2512.09026v1 Announce Type: new +Abstract: The variability of X-rays observed from accreting black hole systems, including quasi-periodic oscillations (QPOs), suggests a complex nonlinear dynamics in the corona. Here, we propose a new theoretical framework for this problem, based on non-equilibrium thermodynamics. In this model, coronal variability arises from feedback between a macroscopic oscillation of the plasma and the rate at which it is cooled by the inverse Compton scattering of soft photons from the disc. The "pair thermostat'' mechanism then allows the corona to act as a heat engine that extracts work cyclically from the underlying thermal disequilibrium between the low-entropy heating and the high-entropy cooling by the soft photons, in close analogy to the well-known $\kappa$-mechanism for pulsating stars. This coronal self-oscillation may explain QPOs without the need to invoke an external resonant driving. Moreover, we argue that this mechanism can provide the power to generate turbulence and jets in the corona. + oai:arXiv.org:2512.09026v1 astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + physics.flu-dyn + physics.plasm-ph + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - S. Garrappa, E. A. Zimmerman, T. Wasserman, E. O. Ofek, A. Gal-Yam, R. Konno, P. Chen, O. Yaron, S. Ben-Ami, C. M. Copperwheat, S. Fainer, A. Horowicz, A. Humpe, P. A. Mazzali, D. Polishook, E. Segre, S. A. Spitzer + Vanessa L\'opez-Barquero (University of Maryland, College Park), Alejandro Jenkins (Universidad de Costa Rica, University of Gda\'nsk), Christopher S. Reynolds (University of Maryland, College Park), Andrew Fabian (University of Cambridge) - Detecting Neutrino Emission from Supernova Remnants: A Theoretically Motivated Target Catalog - https://arxiv.org/abs/2512.07940 - arXiv:2512.07940v1 Announce Type: new -Abstract: Galactic supernova remnants (SNRs) are thought to accelerate cosmic rays (CRs) to several PeV energies, but this has yet to be confirmed as general behavior. Although several sources show ~100 TeV gamma rays, their hadronic origin is uncertain; a matching neutrino signal would provide definitive evidence. Using insight from the theory of diffusive shock acceleration, we evaluate the spectra and environments of the sample of Galactic SNRs to identify those most likely to be hadronic, categorizing them into a tiered catalog depending on their likelihood to produce neutrinos detectable in the TeV-PeV range. We then calculate the estimated stacked sensitivity of IceCube for each tier using IceCube's ten-year public data. Our results suggest that this strategy of stacking SNRs and carefully excluding leptonic sources by using theoretical arguments may allow for a detection of this source class that would otherwise be impossible. A follow-up analysis of these catalogs using TeV-PeV sensitive neutrino data from IceCube (or similar telescopes like KM3NeT/ARCA) offers the most decisive, near-future test for the hadronic nature of these SNRs and the maximum energies of their CR spectra. - oai:arXiv.org:2512.07940v1 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Enhanced rates of stellar radial migration in gas-rich discs at high redshift + https://arxiv.org/abs/2512.09030 + arXiv:2512.09030v1 Announce Type: new +Abstract: Radial migration and dynamical heating redistribute stars within galactic discs and thereby modify the chemo-kinematic structure of their host galaxies. Usually, these secular processes are studied in N-body and hydrodynamical simulations of Milky Way analogues with stellar-dominated discs. In contrast, discs at high redshift are gas-rich, which may qualitatively change how secular evolution proceeds. We use the Nexus framework to construct and evolve a suite of isolated galaxies with fixed halo and disc mass but varying initial disc gas fraction, from 0% to 100%. We show that in gas-rich models, the root-mean-square change in stellar angular momentum is up to a factor of two larger than in gas-poor analogues and is accompanied by stronger radial and vertical heating, leading to enhanced radial mixing. We further dissect the role of gas in specific migration channels. For bar-driven migration, corotation resonance dragging dominates in gas-poor discs, whereas in gas-rich discs, stars more readily reach and accumulate at the outer Lindblad resonance, which acts as a barrier. The high radial mixing efficiency in gas-rich phases can flatten the stellar metallicity gradient relative to that of the initial gaseous disc within only a few orbital timescales. Together, these results imply that radial mixing in early, gas-rich discs is substantially more vigorous than in late-time, gas-poor discs, naturally producing distinct evolutionary tracks for chemically bimodal discs such as that of the Milky Way. + oai:arXiv.org:2512.09030v1 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Emily Simon, Rebecca Diesing, Damiano Caprioli, Stephen Sclafani + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + HanYuan Zhang, Thor Tepper-Garc\'ia, Vasily Belokurov, N. Wyn Evans, Takafumi Tsukui, Hillary Davis, Joss Bland-Hawthorn, Jason L. Sanders, Oscar Agertz - The HIP 54515 b Superjovian Planet as an Early, Critical Look at the Roman Coronagraph's Performance in the Faint Target Star, Small IWA Limit - https://arxiv.org/abs/2512.07942 - arXiv:2512.07942v1 Announce Type: new -Abstract: The Roman Coronagraph's capabilities in the faint star, small IWA limit has enormous scientific (programmatic) impacts. Testing its performance in this limit provides a first look at challenges that may be encountered with the Habitable Worlds Observatory in imaging rocky planets around the nearest K and M stars. We propose such a rigorous test with the HLC/575nm targeting a newly-discovered superjovian planet HIP 54515 b, whose predicted contrast is $\sim$4.7 $\times$10$^{-8}$--2.5 $\times$10$^{-7}$. The companion lies close to the coronagraph IWA (well interior to the TTR5 performance region) and orbits a V = 6.8 star, near the limit for which the coronagraph may yield deep contrasts. Multiple reference stars are available that will further test CGI's performance as a function of $\Delta$ pitch angle to assess how the telescope's thermal environment impacts contrasts. - oai:arXiv.org:2512.07942v1 - astro-ph.IM - astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + Core-wing transitions and the breakdown of diffusion in Lyman-$\alpha$ radiative transfer + https://arxiv.org/abs/2512.09031 + arXiv:2512.09031v1 Announce Type: new +Abstract: The Lyman alpha (LyA) line of neutral hydrogen plays a central role in observations of star-forming galaxies. However, resonant scattering makes it difficult to directly interpret LyA signatures. Monte Carlo radiative transfer (MCRT) calculations have become the gold standard for modeling LyA, but it becomes extremely computationally expensive in optically thick environments. Workarounds, such as core-skipping to avoid repetitive low-transport scatterings, greatly increase the efficiency of MCRT simulations but introduce errors in the solutions. While core-skipping is designed to preserve emergent spectra, the internal radiation field, most importantly, the momentum imparted, is not properly preserved. On the other hand, to make analytical and numerical progress, it is often assumed that photons diffuse in both frequency and physical space. We find that these diffusion approximations break down for frequencies near the core and positions at finite optical depths. We propose a more physically-motivated definition for the core-wing transition frequency to isolate such effects. We derive new spectral distributions of internal radiation properties and compare the results with simulations. We analyze the diffusive properties of LyA photons and demonstrate anomalous spatial diffusion behavior with fat-tailed distributions. This work deepens our understanding of diffusion in resonant-line transfer and identifies areas where simulations or analytics may be failing and how these failures may be resolved. + oai:arXiv.org:2512.09031v1 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Thayne Currie, Yiting Li, Brianna Lacy, Mona El Morsy, Masayuki Kuzuhara, Naoshi Murakami, Danielle Bovie + Kevin Lorinc (UT Dallas), Aaron Smith (UT Dallas), Olof Nebrin (Stockholm), Joshua Kasiri (UT Dallas) - The mass-to-flux ratio in molecular clouds. What are we really measuring? - https://arxiv.org/abs/2512.07943 - arXiv:2512.07943v1 Announce Type: new -Abstract: The mass-to-magnetic flux ratio of molecular clouds is a parameter of central importance as it quantifies the dynamical significance of the magnetic field with respect to gravitational forces. Therefore, it can provide invaluable information on the fate of clouds, and the sites of star formation. Our objective was to study the accuracy with which we can measure the true mass-to-flux ratio in molecular clouds under various projection angles and identify systematic biases. We used a 3D nonideal magnetohydrodynamic chemo-dynamical simulation of a turbulent collapsing molecular cloud. We quantified the accuracy with which the mass-to-flux ratio is recovered under various projection angles and dynamical stages by analyzing the magnetic field - gas column density relation, and comparing the "observed" mass-to-flux ratio against the true values. We find that projection effects have a major effect on measurements of the mass-to-flux ratio. Zeeman measurements can overestimate the true mass-to-flux ratio of the cloud by more than an order of magnitude when the magnetic field primarily lies on the plane of the sky. Therefore, measurements of the mass-to-flux ratio based on Zeeman observations should be considered as upper limits. Mass-to-flux ratio estimates inferred from polarization observations do not provide a physically meaningful probe of the true mass-to-flux ratio and can lead to unphysical results as they fail to capture the underlying correlation between the magnetic field and column density. - oai:arXiv.org:2512.07943v1 + Optimizing Photometric Redshift Training Sets I: Efficient Compression of the Galaxy Color-Redshift Relation with UMAP + https://arxiv.org/abs/2512.09032 + arXiv:2512.09032v1 Announce Type: new +Abstract: Spectroscopic datasets are essential for training and calibrating photometric redshift (photo-$z$) methods. However, spectroscopic redshifts (spec-$z$'s) constitute a biased and sparse sampling of the photometric galaxy population, which creates difficulties for the common grid-based approach for mapping color to redshift using self-organizing maps (SOMs). Instead, we utilized the uniform manifold approximation and projection (UMAP) algorithm to compress a Rubin-Roman-like $ugrizyJH$ color space into a thin and densely-sampled manifold. Crucially, the manifold varies continuously and monotonically in redshift and specific star formation rate in roughly orthogonal directions. Using $\sim$110,000 COSMOS2020 many-band photo-$z$'s and $\sim$15,000 spec-$z$'s as representative and non-representative samples, respectively, we trained and tested redshift estimation from a SOM (SOM-$z$) and from nearest neighbors in UMAP space (UMAP-$k$NN-$z$). Compared to SOM-$z$, UMAP-$k$NN-$z$ exhibited smaller photo-$z$ scatter and fraction of outliers for the representative training set. When training with the highly biased spec-$z$ sample, UMAP-$k$NN-$z$ maintained similar performance, but the outlier fraction for SOM-$z$ increased by nearly three times. The physically-meaningful trends across the UMAP manifold allow for accurate redshift regression even in regions of color space sparsely populated by spectroscopic objects, which comprise nearly 25% of the photometric sample. This suggests that representative, spectroscopically-anchored training sets can be produced by interpolating between spectroscopic sources at the UMAP coordinates of photometric objects, maximizing the performance of photo-$z$ algorithms. + oai:arXiv.org:2512.09032v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Aris Tritsis + Finian Ashmead, Jeffrey A. Newman, Brett H. Andrews, Rachel Bezanson, Biprateep Dey, Daniel C. Masters, S. A. Stanford - Heavy element enriched atmospheres and where they are born - https://arxiv.org/abs/2512.07944 - arXiv:2512.07944v1 Announce Type: new -Abstract: The heavy element content of giant exoplanets, inferred from structure models based on their radius and mass, often exceeds predictions based on classical core accretion. Pebble drift, coupled with volatile evaporation, has been proposed as a possible remedy to this with the level of heavy element enrichment a planet can accrete, as well as its atmospheric composition, being strongly dependent on where in the disc it is forming. We use a planet formation model which simulates the evolution of the protoplanetary disc, accounting for pebble growth, drift and evaporation, and the formation of planets from pebble and gas accretion. The growth and migration of planetary embryos is simulated in 10 different protoplanetary discs which have their chemical compositions matched to the host stars of the planets which we aim to reproduce, providing a more realistic model of their growth than previous studies. The heavy element content of giant exoplanets is used to infer their formation location and thus make a prediction of their atmospheric abundances. We focus here on giants more massive than Saturn, as we expect that their heavy element content is dominated by their envelope rather than their core. The heavy element content of 9 out of the 10 planets simulated is successfully matched to their observed values. Our simulations predict formation in the inner disc regions, where the majority of the volatiles have already evaporated and can thus be accreted onto the planet via the gas. As the majority of the planetary heavy element content originates from water vapour accretion, our simulations predict a high atmospheric O/H ratio in combination with a low atmospheric C/O ratio, in general agreement with observations. For certain planets, namely WASP-84b, these properties may be observable in the near future, offering a method of testing the constraints made on the planet's formation. - oai:arXiv.org:2512.07944v1 - astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + A High-resolution Study of the Cold Neutral Medium in and around 30 Doradus + https://arxiv.org/abs/2512.09035 + arXiv:2512.09035v1 Announce Type: new +Abstract: With the aim of evaluating the roles of the cold neutral medium (CNM) in the cloud-scale baryon cycle, we perform a high-resolution study of the CNM in and around the extreme star-forming region 30 Doradus (30 Dor). For our study, we use Galactic Australian Square Kilometre Array Pathfinder H I Survey data and produce H I emission and absorption cubes on 7 pc scales. To examine the CNM structures toward 30 Dor, we decompose the H I absorption cube into 862 Gaussian components and find that these components are distributed at four velocity ranges (B1, B2, B3, and B4, respectively): 200$-$230 km s$^{-1}$, 230$-$260 km s$^{-1}$, 260$-$277 km s$^{-1}$, and 277$-$300 km s$^{-1}$. We derive line-of-sight average spin temperatures and opacity-corrected total H I column densities and show that the B1$-$B4 structures have systematically different properties, indicating that they are physically distinct. As for the nature of the observed CNM structures, we find that B2 is associated with the main dense structure where ionized, atomic, and molecular gases are concentrated. B3 and B4 trace inflows whose combined mass flux rate of 0.14 $M_{\odot}$ yr$^{-1}$ is comparable to the current star formation rate, while B1 probes outflows with a much lower mass flux rate of 0.007 $M_{\odot}$ yr$^{-1}$. Interestingly, the H I column densities in B1$-$B4 are nearly uniform with a factor of two spatial variations, implying the presence of H I shielding layers for H$_{2}$ formation. + oai:arXiv.org:2512.09035v1 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Barry O'Donovan, Bertram Bitsch + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Gyueun Park, Min-Young Lee, John M. Dickey, Nick M. Pingel, James Dempsey, Helga D\'enes, Steven Gibson, Katie Jameson, Ian Kemp, Chang-Goo Kim, Denis Leahy, Bumhyun Lee, Callum Lynn, Yik Ki Ma, Antoine Marchal, Naomi M. McClure-Griffiths, Eric Muller, Hiep Nguyen, Sne\v{z}ana Stanimirovi\'c, Jacco Th. Van Loon - On the missing dust of super-early galaxies: Supernova blowout and gas-dust venting in Blue Monsters - https://arxiv.org/abs/2512.07945 - arXiv:2512.07945v1 Announce Type: new -Abstract: A subset of very young, super-early galaxies at $z\gtrsim10$, often termed Blue Monsters, shows extremely blue UV continua and faint far-IR emission, which could imply much less dust than expected from standard enrichment scenarios. We seek to understand the possible reason behind the apparent absence of dust in the Blue Monsters. We show how clustered supernovae drive mechanical blowout in stratified, self-gravitating clouds by combining full 3-D hydrodynamical dust-survival yields with 3-D thin-shell scalings, and we predict the retained dust-to-stellar mass ratio at the cluster scale and the corresponding galaxy-integrated value. We take the net dust yield per unit stellar mass from existing 3-D hydrodynamical studies of young stellar clusters with sequential supernovae, and we set the blowout radius as a function of gas concentration using established 3-D thin-shell scalings. Assuming gas-dust coupling across the blowout boundary, the retained dust-to-stellar ratio accounts for the fraction of supernovae that remain confined versus those that vent mechanically. Across typical cluster masses, sizes, and cloud-scale star formation efficiencies, mechanical venting removes a large share of gas and dust. The retained dust-to-stellar mass ratio is lowered by about half to two orders of magnitude relative to the supernova net dust yield. The outcome depends mainly on gas concentration and only weakly on metallicity, so it remains effective at low $Z$. After weighting by a Schechter cluster mass function and a Weibull core-radius distribution, the galaxy-integrated value falls in the same range inferred for spectroscopically confirmed Blue Monsters. Thus, mechanical venting at the cluster scale can account for the very low dust fractions inferred for Blue Monsters without requiring extreme in situ destruction and without fine-tuning. - oai:arXiv.org:2512.07945v1 + Probing the origin of the kilonova candidate GRB 230307A: analysis of host galaxy and offset + https://arxiv.org/abs/2512.09036 + arXiv:2512.09036v1 Announce Type: new +Abstract: We investigate the host galaxy of the long gamma-ray burst GRB 230307A, which is associated with a kilonova candidate likely produced by a binary neutron-star (BNS) merger. The transient occurred at a projected offset of $\sim 40$ kpc from its spiral-galaxy host. We consider two explanations for this large distance: (i) NSs that merge inside a remote globular cluster, or (ii) a BNS that formed in the disk whose orbit was strongly modified by the NS natal kicks. Using JWST data and comparisons with known globular clusters, we show that a globular-cluster origin is extremely unlikely, ruling out case (i). Considering case (ii), using JWST and MUSE data, we derive the host galaxy morphology, stellar mass, estimate the atomic gas (HI+He) contribution, and the host rotation curve. Assuming an NFW halo and applying Bayesian inference, we obtain a mass model for the host galaxy. From this model, we compute the time required for a disk-formed BNS, with a given natal kick, to reach the observed offset while marginalizing over uncertainties and over the initial position in the disk. We compare these results with BNS-merger simulations from the SEVN population-synthesis code combined with PARSEC stellar evolutionary tracks, which provide the coalescence time and kick velocity for each realization. The two approaches have an overlap in the kick-time diagram, but only 0.1\% of the simulated systems fall within the 2$\sigma$ region of the galaxy mass model. This indicates that a disk origin is possible, but requires fine-tuned conditions for the kilonova to occur at such a large distance from the host galaxy. + oai:arXiv.org:2512.09036v1 + astro-ph.HE astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Sergio Mart\'inez-Gonz\'alez, Santiago Jim\'enez, Casiana Mu\~noz-Tun\'on + Clecio R. Bom, Davi C. Rodrigues, Arianna Cortesi, Amanda E. Araujo-Carvalho, Daniel Ruschel-Dutra, Giuliano Iorio, Luidhy Santana-Silva, Charles D. Kilpatrick, Fabricio Ferrari, Luis Lomeli-Nu\~nez, Thomas Harvey, Duncan Austin, Christopher J. Conselice, Nathan Adams, Roberto Cid Fernandes - How is cold, star-forming gas in galaxies affected by magnetic fields? - https://arxiv.org/abs/2512.07948 - arXiv:2512.07948v1 Announce Type: new -Abstract: Numerical simulations provide a unique opportunity to improve our understanding of the role of magnetic fields in the interstellar medium of galaxies and in star formation. However, many existing galaxy-scale numerical simulations impose a Kennicutt-Schmidt (KS) star formation law by construction. In this paper, we present two Arepo simulations of an isolated star-forming galaxy with and without magnetic fields, using sink particles to model star formation without imposing a KS relation. We examine global differences between the models, and investigate the impacts on star formation. We include a time-dependent, non-equilibrium chemical network coupled to a thermal evolution scheme and supernova feedback. Our magnetic field amplifies via dynamo action from a small initial seed field. We find a more compact magnetohydrodynamic (MHD) disc (radius ~ 5.1kpc, compared to ~ 7.4kpc), with a diffuse atomic envelope above and below the plane that is not seen in the hydrodynamic (HD) case. The HD disc displays a smoother, more even radial distribution of gas and star formation, and more bubbly substructure. Our MHD simulation has a higher proportion of dense, gravitationally unbound gas than the HD case, but a lower star formation rate, an average between 125-150Myr of ~ 4.8 solar masses per year, compared to ~ 8.4 solar masses per year. We see a clear shift in the KS relation to higher gas surface densities in the MHD case, more consistent with observations. The additional magnetic support against gravitational collapse seems to raise the threshold gas surface density required for star formation. - oai:arXiv.org:2512.07948v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Characterising the X-ray variability of QSOs to the highest Eddington ratios and black hole masses with eROSITA light curves + https://arxiv.org/abs/2512.09047 + arXiv:2512.09047v1 Announce Type: new +Abstract: An important diagnostic of the inner structure of accretion flows onto supermassive black holes are the stochastic flux variations at X-ray wavelengths. Despite its significance, a systematic characterisation of the statistical properties of the X-ray variability to the highest Eddington ratios and most massive black holes is still lacking. In this paper we address this issue using SRG/eROSITA 5-epoch light curves to characterise the mean X-ray variability of optically selected SDSS QSOs extending to black holes masses of $10^{10}$ solar and accretion rates close to the Eddington limit. The adopted variability statistic is the ensemble normalised excess variance, which is measured using a novel hierarchical Bayesian model (eBExVar) tailored to the Poisson nature of the X-ray light curves. We find a clear anti-correlation of the ensemble variability with black hole mass, extending previous results to time scales of months. This can be interpreted as evidence for an X-ray corona size and/or physical conditions that scale with black holes mass. We also find an unexpected increase of the ensemble normalised excess variance close to the Eddington limit, which is contrary to the predictions of empirical variability models. This result suggests an additional variability component for fast growing black holes that may be related to systematic variations of the hot corona size with Eddington ratio or shielding of the hot corona by an inner puffed-up disk and/or outflows. + oai:arXiv.org:2512.09047v1 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Kamran R. J. Bogue, Rowan J. Smith, Robin G. Tress, Mordecai-Mark Mac Low, David Whitworth, Ralf S. Klessen, No\'e Brucy, Philipp Girichidis, Simon C. O. Glover, Junia G\"oller, Juan D. Soler, Alessio Traficante + http://creativecommons.org/licenses/by/4.0/ + Antonis Georgakakis, Angel Ruiz, Johannes Buchner, Iossif Papadakis, Maria Chira, Kirpal Nandra, Shi-Jiang Chen, Maurizio Paolillo, Qingling Ni, Mara Salvato, Thomas Boller, Andrea Merloni - The dynamic central environment of NGC 3516 revealed by XRISM - https://arxiv.org/abs/2512.07950 - arXiv:2512.07950v1 Announce Type: new -Abstract: We present a detailed, time-resolved analysis of the Fe K band of the Seyfert 1.5 galaxy NGC 3516 observed with XRISM. The 249 ks observation spanning $\sim$310 ks in elapsed time reveals an exceptionally rich and time-variable absorption spectrum. Six distinct absorption components are detected across multiple ionization states, spanning more than an order of magnitude in ionization parameter and a wide range of systemic velocities, from a potential inflow ($+4300~\rm km~s^{-1}$) to a mildly relativistic ultra-fast outflow ($-9800~\rm km~s^{-1}$). Despite their diversity, the components exhibit relatively small broadening ($\lesssim$$400~\rm km~s^{-1}$), implying comparable internal dynamics within a medium of a complex structure. Time-resolved spectroscopy reveals pronounced variability in three highly ionized absorbers, with Fe XXV$-$Fe XXVI features that appear and disappear on timescales of tens of kiloseconds. This behavior likely reflects a combination of geometrical transits of clumpy gas and ionization-state changes driven by continuum variability. An additional temporary absorption feature in the red wing of the Fe K$\alpha$ line, consistent with Fe XXV absorption, indicates a possible transient ultra-fast inflow at $\sim$$15\,000~\rm km~s^{-1}$ ($\sim$5% $c$). Finally, the continuum light curve exhibits a tentative $\sim$40 ks oscillatory pattern, accompanied by correlated shifts of a weak, narrow Fe K$\alpha$ emission feature, suggesting dynamic coupling between the continuum and the line-emitting region. Together, these results reveal that the nuclear environment of NGC 3516 is dominated by rapidly evolving, multi-phase gas flows, where accretion, ejection, and ionization processes are tightly coupled on sub-parsec scales. - oai:arXiv.org:2512.07950v1 + On the connection between galaxy orientation and halo absorption properties + https://arxiv.org/abs/2512.09075 + arXiv:2512.09075v1 Announce Type: new +Abstract: We present a systematic investigation of the azimuthal dependence of metal-line absorption in the circumgalactic medium (CGM) using a uniformly selected sample of 87 isolated galaxies at z < 0.4 from the Magellan MagE MgII (M3) halo survey. High-quality archival imaging enables quantitative morphological measurements -- including disk inclination and position angle -- for every galaxy, providing a robust framework for assessing how absorber strength depends on the geometric alignment between galaxies and the QSO sightlines. All galaxies have associated constraints on MgII lambda 2796 absorption, and a subset of 56 galaxies also have measurements of CaII lambda 3934. We compare rest-frame MgII and CaII equivalent widths with both projected distance and deprojected galactocentric distance. Across the full sample, we find no statistically significant correlation between absorption strength and azimuthal angle. Restricting to the 71 galaxies with well-determined disk orientations reveals a mild excess of strong MgII absorbers near the projected major axis, but a Kendall's tau test confirms that this trend is not statistically significant. CaII absorption, which exhibits a low covering fraction of kappa_CaII = 0.18^{+0.06}_{-0.04} within 50 kpc for W_r(3934) > 0.1 Ang, shows no measurable azimuthal dependence. To assess potential biases, we quantify the effects of projection, disk inclination, and variations in imaging quality. After accounting for these systematics, the spatial distribution of low-redshift MgII and CaII absorbers is consistent with arising from a randomly distributed population, with no compelling evidence for azimuthal anisotropy at d <~ 50 kpc. A larger sample with robust constraints on the disk orientation will be required to uncover or rule out subtle anisotropic trends. + oai:arXiv.org:2512.09075v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Anna Jur\'a\v{n}ov\'a, Erin Kara, Ehud Behar, Elisa Costantini, Jon M. Miller, Daniele Rogantini, James N. Reeves, Valentina Braito, Jacobo Ebrero, Luigi Gallo, Noa Keshet, Gerard A. Kriss, Missagh Mehdipour, Hirofumi Noda, Atsushi Tanimoto, Francesco Tombesi, Tracey J. Turner, Satoshi Yamada - - - LEGA-C stellar populations scaling relations. I: Chemo-archaeological downsizing trends at z~0.7 - https://arxiv.org/abs/2512.07952 - arXiv:2512.07952v1 Announce Type: new -Abstract: We analyze stellar population properties of 552 galaxies at redshift 0.6<z<0.77 from the LEGA-C spectroscopic survey. This first paper in a series presents the catalog of revised absorption indices for LEGA-C DR3 and inferred physical parameters, and derives benchmark scaling relations for the general massive galaxy population at intermediate redshift. We estimate light-weighted mean ages and stellar metallicities by interpreting key stellar absorption features and rizYJ photometry in a Bayesian framework with a comprehensive library of model spectra based on stochastic star formation and metallicity histories and dust attenuations. We discuss systematic uncertainties within our method and compared to other spectral fitting approaches. We derive volume-weighted scaling relations of light-weighted mean ages and stellar metallicities with stellar mass for the general galaxy population at <z>=0.7 and masses >10^10Msun. The downsizing trends observed locally were already in place 6 Gyr ago. We observe bimodal age distribution as a function of mass, transitioning around 10^11Msun. No bimodality appears in the stellar metallicity-mass relation, which changes from steep to flat across 10^10.8Msun. Similar trends emerge for age and metallicity with velocity dispersion, but with sharper transition from young to old around log(sigma)=2.3. Differences with respect to trens with stellar mass suggest that age primarily depends on velocity dispersion below and above the transition regime, while both stellar mass and velocity dispersion contribute to stellar metallicity. The catalogs of revised absorption index measurements for LEGA-C DR3 and inferred stellar population physical parameters will be released to public repositories. (Abridged) - oai:arXiv.org:2512.07952v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Anna R. Gallazzi (INAF-Arcetri Astrophysical Observatory), Stefano Zibetti (INAF-Arcetri Astrophysical Observatory), Arjen van der Wel (Sterrenkundig Observatorium Universiteit Gent), Angelos Nersesian (Sterrenkundig Observatorium Universiteit Gent), Yasha Kaushal (University of Pittsburgh), Rachel Bezanson (University of Pittsburgh), Francesco D'Eugenio (University of Cambridge), Eric F. Bell (University of Michigan), Joel Leja (Pennsylvania State University), Laura Scholz-Diaz (INAF-Arcetri Astrophysical Observatory), Po-Feng Wu (National Taiwan University), Camilla Pacifici (StSCI Baltimore), Michael Maseda (StSCI Baltimore), Daniele Mattolini (INAF-Arcetri Astrophysical Observatory, Universita' di Trento) + Rohan Venkat (The University of Chicago), Soo May Wee (The University of Chicago), Hsiao-Wen Chen (The University of Chicago) - Tracing Nitrogen Enrichment across Cosmic Time with JWST - https://arxiv.org/abs/2512.07955 - arXiv:2512.07955v1 Announce Type: new -Abstract: We present a comprehensive analysis of the nitrogen-to-oxygen (N/O) abundance ratio in star-forming galaxies at redshift z~1-6, with a median redshift of z=2.7, using deep JWST/NIRSpec spectroscopy. Leveraging detections of faint auroral emission lines in 76 galaxies at z>1 from both the MARTA survey and a large compilation of high-redshift literature objects, we derive direct electron temperature-based abundances for nitrogen and oxygen using rest-frame optical lines. We establish the first high-redshift calibrations of strong-line N/O diagnostics based on direct abundance measurements, finding no significant evolution for either N2O2 = [NII]6585/[OII]3727,3729 and N2S2 = [NII]6585/[SII]6717,6731 diagnostics compared to local realisations. We then investigate the N/O-O/H relation across cosmic time using both direct abundances and strong-line based measurements (additional 430 galaxies). We find evidence for mild but systematic nitrogen enhancement at high redshift: galaxies at z>1 exhibit N/O ratios elevated by ~0.18 dex (median offset) at fixed O/H compared to the local relation, with a more pronounced enhancement at low metallicity (12+log(O/H) < 8.1) where the offset reaches up to ~0.3-0.4 dex. Our results provide the most extensive confirmation of elevated N/O ratios at high-redshift to date based on rest-optical diagnostics. The chemical signatures of N/O-enhanced galaxies in our sample resembles that of first-generation globular cluster stars, suggesting that the moderate nitrogen enhancement may reflect the late stages of a cluster-driven enrichment mode that dominated at earlier cosmic epochs. However, the relevance and relative contribution of different mechanisms (e.g. burstiness of the star-formation history, contribution from older stellar populations, differential metal-loaded outflows, inflows of pristine gas) remains to be fully disentangled. - oai:arXiv.org:2512.07955v1 + Unsupervised Kinematic Dissection of the Solar Neighborhood: Identifying Stellar Moving Groups with Gaia DR3 + https://arxiv.org/abs/2512.09078 + arXiv:2512.09078v1 Announce Type: new +Abstract: We present a comprehensive kinematic analysis of the solar neighborhood (d < 50 pc) using high-precision astrometric data from the third Gaia Data Release (DR3). By leveraging the full six dimensional phase space information (positions and velocities), we apply the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm to blindly identify stellar overdensities in the Galactocentric Cartesian velocity space (U, V, W ). Our unsupervised machine learning approach successfully recovers the kinematic cores of major local moving groups, including the Hyades and Pleiades streams, without prior assumptions regarding their membership or spatial distribution. We analyze the velocity dispersion and structural properties of these associations, demonstrating that automated clustering algorithms are robust tools for mapping the complex dynamical history of the local Milky Way disk. These results confirm the hierarchical nature of stellar kinematic substructures and provide a catalog of high-probability members for future spectroscopic follow-up. + oai:arXiv.org:2512.09078v1 astro-ph.GA - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - E. Cataldi, F. Belfiore, M. Curti, B. Moreschini, A. Marconi, R. Maiolino, A. Feltre, M. Ginolfi, F. Mannucci, G. Cresci, X. Ji, A. Amiri, M. Arnaboldi, E. Bertola, C. Bracci, M. Ceci, A. Chakraborty, F. Cullen, Q. D'Amato, C. Kobayashi, I. Lamperti, C. Marconcini, M. Scialpi, L. Ulivi, M. V. Zanchettin + Aanmay Raj - Forecasting Dark Matter Subhalo Constraints from Stellar Streams using Implicit Likelihood Inference - https://arxiv.org/abs/2512.07960 - arXiv:2512.07960v1 Announce Type: new -Abstract: The evidence for dark matter (DM) remains compelling, although attempts to understand its particle nature remain inconclusive. One promising method to study DM is detecting DM subhalos through their gravitational interactions with stellar streams. In this study, we apply Neural Posterior Estimation (NPE) to constrain subhalo interaction parameters, including mass, scale radius, velocity, and encounter geometry, from stellar stream kinematics. We generate particle spray simulations based on the Lagrange Cloud stripping technique, focusing on the ATLAS-Aliqa Uma stream as a test case. We train multiple NPE models across multiple observational scenarios, quantifying how kinematic completeness affects inference and forecasting constraints from upcoming surveys including LSST, 4MOST, and 10-year Gaia data. Our results demonstrate that NPE can produce accurate and well-calibrated posteriors. In the idealized case with full 6D coordinates, we achieve subhalo mass uncertainties of 15-20% for a $10^7 \, \mathrm{M_\odot}$ subhalo, with 5D coordinates (excluding radial velocities) achieving similar performance. Under realistic observational conditions, mass uncertainties range from 50% (present-day) to 20-40% (future scenarios), with comparable performance between the photometric-only LSST sample and a smaller sample that includes Gaia proper motions and 4MOST radial velocities. Most notably, we find that velocity bimodality emerges when phase space is poorly sampled, whether due to missing kinematic information or limited stellar tracers. Combining large photometric samples with targeted spectroscopic follow-up can effectively resolves this degeneracy. These results demonstrate the power of implicit likelihood inference for optimizing stellar stream observational strategies and forecasting DM subhalo constraints from upcoming surveys. - oai:arXiv.org:2512.07960v1 + High deuteration of methanol in L1544 + https://arxiv.org/abs/2512.09110 + arXiv:2512.09110v1 Announce Type: new +Abstract: Isotopic fractionation is a very powerful tool to follow the evolution of material from one stage to the next in the star-formation process. Pre-stellar cores exhibit some of the highest levels of deuteration because their physical conditions greatly favor deuteration processes. Deuteration maps are a measure of the effectiveness of the deuteration across the core, and they are useful to study both the deuteration as well as the formation mechanism of the main species. Methanol is the simplest O-bearing complex organic molecule (COM) detected in the interstellar medium (ISM). It represents the beginning of molecular complexity in star-forming regions, thus a complete understanding of its formation and deuteration is a necessary step to understand the development of further chemical complexity. In this paper, we use single-dish observations with the IRAM 30 m telescope and state-of-the-art chemical models to investigate the deuteration of methanol towards the prototypical pre-stellar core L1544. We also compare the results of the chemical models with previous observations of deuterated methanol towards the pre-stellar cores HMM1 and L694-2. The spectra extracted from the CHD$_2$OH map show that the emission is concentrated in the center and towards the north-west of the core. Using deep observations towards the dust and the methanol peaks of the core, we derive a very large deuterium fraction for methanol ($\sim20\%$) towards both peaks. The comparison of our observational results with chemical models has highlighted the importance of H-abstraction processes in the formation and deuteration of methanol. Deep observations combined with state-of-the-art chemical models are of fundamental importance in understanding the development of molecular complexity in the ISM. Our analysis also shows the importance of non-LTE effects when measuring the D/H ratios in methanol. + oai:arXiv.org:2512.09110v1 astro-ph.GA - astro-ph.CO - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Tri Nguyen, Rutong Pei, Zhuofu Li, Nora Shipp, Scott Dodelson, Denis Erkal, Peter S. Ferguson, Tjitske K. Starkenburg, Markus M. Rau, Alexander H. Riley, Alan Junzhe Zhou, the LSST Dark Energy Science Collaboration + S. Spezzano, W. Riedel, P. Caselli, O. Sipil\"a, Y. Lin, H. A. Bunn, E. Redaelli, L. H. Coudert, A. Meg\'ias, I. Jimenez-Serra - Probing Infrared eXcess to Investigate Early-Universe Dust (PIXIEDust) - https://arxiv.org/abs/2512.07964 - arXiv:2512.07964v1 Announce Type: new -Abstract: Despite the implied presence of dust through reddened UV emission in high-redshift galaxies, no dust emission has been detected in the (sub)millimetre regime beyond $z > 8.3$. This study combines around two hundred hours of Atacama Large Millimeter/submillimeter Array (ALMA) and Northern Extended Millimeter Array (NOEMA) observations on ten $z > 8$ galaxies, revealing no significant dust emission down to a $1 \sigma$ depth of $2.0$, $2.0$, and $1.5 \,\mu$Jy at rest-frame 158, 88 $\mu$m, and across all the data, respectively. This constrains average dust masses to be below $< 10^{5}$ M$_{\odot}$ at $3 \sigma$ and dust-to-stellar mass ratios to be below $3.7 \times{} 10^{-4}$ (assuming $T_{\rm dust} = 50$ K and $\beta_{\rm dust} = 2.0$). Binning by redshift ($8 < z < 9.5$ and $9.5 < z < 15$), UV-continuum slope ($\beta_{\rm UV} \lessgtr -2$) and stellar mass ($\log_{10} M_{\ast}/{\rm M_{\odot}} \lessgtr 9$) yields similarly stringent constraints. Combined with other studies, these results are consistent with inefficient dust build-up in the $z > 8$ Universe, likely due to inefficient supernova production, limited interstellar grain growth and/or ejection by outflows. We provide data and tools online to facilitate community-wide high-redshift dust searches. - oai:arXiv.org:2512.07964v1 + Distance to the Globular Cluster M 3 from the Infrared Surface Brightness Technique applied to RR Lyrae stars + https://arxiv.org/abs/2512.09119 + arXiv:2512.09119v1 Announce Type: new +Abstract: The Infrared Surface Brightness (IRSB) technique is a specific application of the Baade-Wesselink method. Given a proper calibration, well covered optical and near-infrared photometry, as well as radial velocity curves, it allows for estimation of distances to individual pulsating stars and determination of their mean radii. The technique is fully empirical and does not depend on stellar atmosphere models. + The goal of the work is to test the precision of distance determinations to individual RR Lyrae stars and to their host system as a whole using the IRSB technique for a relatively distant globular cluster M 3 (NGC 5272). We also aim to determine mean radii and period-radius relations for these stars in order to compare them with the existing theoretical prediction and empirical estimations for the field stars from the solar neighborhood. + We use data available in the literature and the calibration of the IRSB technique based on the RR Lyrae stars from the solar neighborhood we published previously in order to determine distances to 14 RR Lyrae stars in the globular cluster M 3. We study the impact of the selection of the fitting procedure (bisector v.s. the LS fit) on the results. We apply five different empirical surface brightness-color relations from the literature in the analysis. + We obtained a mean distance to M 3 of $r_{M3} = (10.07 \pm 0.19 \pm 0.29) \,kpc$ that corresponds to a distance modulus ${\mu}_{M3} = (15.015 \pm 0.041 \pm 0.063) \,mag$ and a $7\%$ scatter of individual stellar distances for 14 RR Lyrae stars in M 3. We received a very good agreement between the two fitting techniques. We also determined mean stellar radii for pulsators from the sample with a precision of $0.5\%$ and obtained excellent agreement with a theoretical prediction of the period-radius relation for RRab stars available in the literature. + oai:arXiv.org:2512.09119v1 + astro-ph.SR astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Tom J. L. C. Bakx, Hiddo S. B. Algera, Jean-Baptiste Jolly, Clarke Esmerian, Kirsten Knudsen, Laura Sommovigo, Joris Witstok, Stefano Carniani, Jianhang Chen, Stephen Eales, Andrea Ferrara, Yoshinobu Fudamoto, Masato Hagimoto, Takuya Hashimoto, Hanae Inami, Akio K. Inoue, Theo Khouri, Ikki Mitsuhashi, Gunnar Nyman, Gustav Olander, Stephen Serjeant, Renske Smit, Ilsang Yoon, Jorge Zavala, Susanne Aalto, Caitlin M. Casey, Yoichi Tamura, Wouter Vlemmings + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Bart{\l}omiej Zgirski, Wolfgang Gieren, Grzegorz Pietrzy\'nski, Gergely Hajdu, Piotr Wielg\'orski, Marek G\'orski, Jesper Storm, Nicolas Nardetto, Alexandre Gallenne, Garance Bras, Pierre Kervella, Paulina Karczmarek, Weronika Narloch - von Zeipel-Kozai-Lidov oscillations in nearby bright stars. I. Lambda Ophiuchi - https://arxiv.org/abs/2512.07970 - arXiv:2512.07970v1 Announce Type: new -Abstract: The challenge of constraining both the inner and the outer orbits in multiple stars has resulted in a growing abyss between the rich theoretical and the sparse observational studies of von Zeipel-Kozai-Lidov (ZKL) oscillations in stellar systems. Here we solve for the full orbital architecture of the bright intermediate-mass nearby system Lambda Ophiuchi based on astrometric measurements of the outer orbit (period of 129 years) compiled in the Sixth Catalog of Orbits of Visual Binary Stars and new VLTI/GRAVITY interferometric measurements that are used to determine the inner orbit (period of 42 days). The orbits are retrograde and misaligned by either $88.5\pm1.9^o$ or $113.5\pm1.9^o$, which in either case results in the inner binary currently undergoing ZKL oscillations. While pure Newtonian point source evolution would have predicted the stars in the inner binary to have merged long ago, in reality the eccentricity oscillations are significantly modulated by general relativistic, tidal and rotational bulge precession. We show that due to the effect of ``slaved'' precession the dynamics can still be solved semi-analytically. We find that the (currently unknown) inclination angles between the stellar spins axes and the inner orbital axis play a very important role in the amplitude of the ZKL oscillations, which is at a minimum $\Delta e = e_{\mathrm{max}} - e_{\mathrm{min}} \simeq 0.15$ and could be as high as $\Delta e \simeq 0.70$. We argue that currently feasible spectroscopic and interferometric observations could allow for a complete and unique dynamical solution for this system. - oai:arXiv.org:2512.07970v1 - astro-ph.SR + Metrics for Optimizing Searches for Orbital Precession and Tidal Decay via Transit- and Occultation-Timing + https://arxiv.org/abs/2512.09122 + arXiv:2512.09122v1 Announce Type: new +Abstract: Short-period exoplanets may exhibit orbital precession driven by several different processes, including tidal interactions with their host stars and secular interactions with additional planets. This motion manifests as periodic shifts in the timing between transits which may be detectable via high-precision and long-baseline transit- and occultation-timing measurements. Detecting precession and attributing it to a particular process may constrain the tidal responses of planets and point to the presence of otherwise undetected perturbers. However, over relatively short timescales, orbital decay driven by the same tidal interactions can induce transit-timing signals similar to the precession signal, and distinguishing between the two processes requires robust assessment of the model statistics. In this context, occultation observations can help distinguish the two signals, but determining the precision and scheduling of observations sufficient to meaningfully contribute can be complicated. In this study, we expand on earlier work focused on searches for tidal decay to map out simple metrics that facilitate detection of precession and how to distinguish it from tidal decay. We discuss properties for a short-period exoplanet system that can maximize the likelihood for detecting such signals and prospects for contributions from citizen-science observations. + oai:arXiv.org:2512.09122v1 astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Idel Waisberg, Ygal Klein, Boaz Katz + Brian Jackson, Elisabeth R. Adams, Rachel M. Huchmala, Malia Barker, Marvin Rothmeier, Jeffrey P. Morgenthaler, Amanda A. Sickafoose - Stellar Multiplicity via Speckle Interferometry with the 3.6 m Devasthal Optical Telescope - https://arxiv.org/abs/2512.07971 - arXiv:2512.07971v1 Announce Type: new -Abstract: Conventional ground-based optical telescopes, even those with large apertures, primarily observe stars, close binaries, and multiple systems as unresolved point sources through photometric measurements. Spectroscopy can identify multiple stellar components within a system, but both techniques are fundamentally limited in resolving stellar surfaces and providing direct angular separations. Although photometric and spectroscopic observations yield critical information on magnitudes/flux, metallicities, and orbital properties, complementary high-angular-resolution methods are required to constrain additional system characteristics, including angular orbital parameters, model-independent distances, radii, and stellar masses. The limitations of these two methods arise due to the Diffraction Limit of the telescopes and atmospheric turbulence. Speckle Interferometry (SI) is a clever and affordable method for ground-based telescopes to work around atmospheric turbulence. In this work, we utilize the speckle images obtained by the 3.6 m DOT and demonstrate the capability of SI to resolve binary systems, measure their orbital separations, and determine their position angles. For systems with faint companions where conventional analysis fails, we employ Bayesian inference to model speckle patterns and estimate orbital parameters with high precision. These results establish the effective methodology for using a medium-sized, 4-m class telescope like the DOT as a high-resolution stellar interferometer and demonstrate the potential of speckle interferometry as a powerful technique to advance optical interferometric studies within Indian astronomy. - oai:arXiv.org:2512.07971v1 + Computing the Electronic Gain for Detectors Read Out Up-The-Ramp + https://arxiv.org/abs/2512.09131 + arXiv:2512.09131v1 Announce Type: new +Abstract: The electronic gain -- the conversion between photoelectrons on a pixel and the digital number recorded to disk -- gives physical units to an astronomical image and sets the relation between pixel value and photon noise. This paper presents a new, likelihood-based approach to derive the gain from images taken up-the-ramp, where the detector is read out nondestructively many times before being reset. Our method makes full use of the individual reads assuming an ideal detector subject to photon noise and Gaussian read noise. We extend the method to account for slight nonlinearities in the relation between photoelectrons and measured counts. We demonstrate that our likelihood-based approach provides a consistent (i.e. asymptotically correct) and nearly unbiased estimator of the gain both with and without fitting for nonlinearity. Finally, we apply this approach to a single detector from the Wide-Field Instrument on the Roman Space Telescope, and show how pixel-to-pixel gain variations describe much of the variations in pixel response seen in flatfield images. Code to compute gain and regenerate figures in this paper is available at https://github.com/RomanSpaceTelescope/SOCReferenceFileCode. + oai:arXiv.org:2512.09131v1 astro-ph.IM - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Km Nitu Rai, Neelam Panwar, Jeewan C Pandey, T S Kumar, Subrata Sarangi, Prasenjit Saha + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Timothy D. Brandt - Chemical Signatures of AGB Mass Transfer in Gaia White Dwarf Companions - https://arxiv.org/abs/2512.07972 - arXiv:2512.07972v1 Announce Type: new -Abstract: We present a homogeneous abundance analysis of 160 main-sequence stars in astrometric white-dwarf + main-sequence (WD+MS) binaries with orbits from Gaia DR3. These systems have AU-scale separations and are thought to have undergone mass transfer (MT) when the WD progenitor was an asymptotic giant branch (AGB) star. Using high-resolution spectroscopy, we measure chemical abundances of the MS stars, focusing on s-process elements. Since s-process nucleosynthesis occurs mainly in AGB stars, s-process enhancement in the MS star is a key signature of accretion from an AGB companion. We identify 40 barium dwarfs -- 36 of them newly discovered -- roughly doubling the known population in astrometric WD+MS binaries and extending it to lower metallicities than previously studied. The s-process abundances show large star-to-star variations that correlate with component masses and with metallicity but not with orbital separation. At the lowest metallicities, three barium dwarfs display strong CH and $\rm C_2$ absorption bands, linking them to CEMP-s stars and implying that AGB mass transfer usually leads to strong carbon enhancement at low metallicity. By comparing the observed abundance patterns to AGB nucleosynthesis models, we show that the diversity of s-process enhancements can be explained by variations in donor mass, metallicity, and most importantly, the number of thermal pulses the AGB star experienced before the onset of MT. Variation in the depth of the accretors' convective envelopes, with which accreted material is diluted, strengthens correlations with MS star mass and metallicity. Our results establish Gaia WD+MS binaries as a powerful laboratory for constraining binary mass-transfer physics and the origins of chemically peculiar stars. - oai:arXiv.org:2512.07972v1 - astro-ph.SR - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + A Classic Nonlinearity Correction Algorithm for Detectors Read Out Up-The-Ramp + https://arxiv.org/abs/2512.09132 + arXiv:2512.09132v1 Announce Type: new +Abstract: We derive an algorithm for computing a classic nonlinearity correction -- applicable to constant and uniform illumination -- in the presence of read noise and photon noise. The algorithm operates simultaneously on many nondestructive ramps at a range of count rates and directly computes the function transforming measured counts into linearized counts. We also compute chi squared for the corrected ramps, enabling the user to identify the polynomial degree beyond which chi squared ceases to improve significantly. The computational cost of our algorithm is linear in the number of reads and ramps, reaching ~100 hours to derive a correction for all 4096 x 4096 pixels of a Hawaii-4 RG detector from 186 illuminated 55-read ramps on a 2023 Macbook Pro laptop (~10,000 reads per pixel). We identify a potential source of bias in the nonlinearity correction when combining ramps of very different illuminations, together with effective mitigations. We apply our algorithm to a random set of pixels from the Roman Space Telescope's Wide Field Instrument. We find that a >=9th order nonlinearity correction is needed, at which point chi squared is close to its theoretically expected value and beyond which chi squared improves little with increasing polynomial order. Python software implementing our algorithm is available at https://github.com/RomanSpaceTelescope/SOCReferenceFileCode. + oai:arXiv.org:2512.09132v1 + astro-ph.IM + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Natsuko Yamaguchi, Kareem El-Badry, Henrique Reggiani, Ren\'e Andrae, Sahar Shahaf + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Timothy D. Brandt - Danger Zone: Establishing Buffers for Enhanced Classification in BPT Diagrams - https://arxiv.org/abs/2512.07975 - arXiv:2512.07975v1 Announce Type: new -Abstract: This study utilizes unsupervised machine learning, specifically the uniform manifold approximation and projection (UMAP) algorithm, to classify optical spectra originating from star-forming regions, Seyferts, and low-ionization (nuclear) emission-line regions (LI(N)ERs) based on their line ratios. Typically, the ionization source of a region is determined from intensity ratio of different combinations of pairs of spectral lines. However, using current boundary definitions, $\sim10$\% of spectra change classes between diagnostic diagrams. We apply the machine learning technique to $\sim$1.3 million optical spectra from 6,439 galaxies observed in the MaNGA survey. By training UMAP on consistently classified data, we can classify these ``ambiguous'' spectra, and delineate boundary zones where such ambiguities arise. Furthermore, we identify physically interesting subsets within the ambiguous spectra. Future work will incorporate additional parameters, such as alternative emission line ratios and velocity dispersions, to enhance classification accuracy. - oai:arXiv.org:2512.07975v1 + The Early Maturity of High-Redshift Galaxies: Insights from sSFR, M/L and SFHs at z~7-14 + https://arxiv.org/abs/2512.09139 + arXiv:2512.09139v1 Announce Type: new +Abstract: The James Webb Space Telescope (JWST) has revealed an unexpected excess of UV-bright galaxies at z>10, unaccounted for by extrapolations from pre-JWST observations and theoretical models. Understanding the physical properties and star formation histories (SFH) of high redshift systems is key to distinguish between the different proposed scenarios. We identify and analyse a sample of 2420 robust candidates at z~7-14 drawn from the ASTRODEEP-JWST dataset over ~0.2 deg^2 and model their properties with non-parametric SFHs to derive their specific star formation rate (sSFR) and stellar population properties. We find that the median sSFR and M/L remain roughly constant across the probed redshift range. We show that this result is robust against potential systematics unless a hidden population of dust-enshrouded starbursts, undetectable in current data, exists at these redshifts. In any case, the absence of observed high-sSFR systems at the highest redshifts suggests that any dust-free starburst phase must be short-lived. The observed sSFR evolution is in tension with most (though not all) theoretical models, making it a key quantity for discriminating among competing scenarios. The sample shows a wide range of physical conditions and galaxy classes, including systems with low sSFR and high mass-to-light ratios (M/L) up to z~10, indicative of already evolved galaxies only a few hundred Myr after the Big Bang, and different degrees of dust attenuation. We finally attempt to reconstruct the assembly histories of two sub-samples: a) the highest-M/L galaxies at z~7-8, which appear to have formed the bulk of their stars at least 500 Myr before observation, implying progenitors observable as UV-bright sources at z>20, and b) z>11 galaxies, which formed through stochastic SFH, remaining UV-faint for most of their early evolution, before undergoing recent (~50 Myr old) episodes of major growth. + oai:arXiv.org:2512.09139v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Changhyun Cho, Ahmad Nemer, Ivan Yu. Katkov, Joseph D. Gelfand + P. Santini, M. Castellano, A. Calabr\`o, A. Fontana, E. Merlin, D. Bevacqua, P. Bergamini, S. Cantarella, L. Ciesla, A. Ferrara, S. L. Finkelstein, F. Fortuni, G. Gandolfi, T. Gasparetto, E. Giallongo, N. A. Grogin, S. T. Guida, A. M. Koekemoer, N. Menci, L. Napolitano, D. Paris, L. Pentericci, B. Perez-Diaz, B. Stoyanova, T. Treu - Growth and thermal evolution of icy planetesimals - https://arxiv.org/abs/2512.07978 - arXiv:2512.07978v1 Announce Type: new -Abstract: Icy planetesimals are likely to supply volatiles to terrestrial planets and serve as building blocks of icy bodies in the outer Solar System. Samples from the C-type asteroid Ryugu, collected by the Hayabusa-2 spacecraft, indicate a low-temperature history with aqueous alteration and organic materials. In contrast, iron meteorites with isotopic ratios similar to carbonaceous chondrites suggest exposure to higher temperatures. These findings imply that the thermal evolution of icy planetesimals is highly diverse. Since direct exploration provides only localized data, understanding this diversity requires comparing observational results with model calculations incorporating key evolutionary processes. We develop a model including radial growth, impact heating, water phase changes, aqueous alteration, and structural differentiation, to re-evaluate the thermal evolution of icy planetesimals during the first 100 Myr after CAI formation. The model considers final radius (10-1000 km), growth onset (1.0 or 2.0 Myr after CAI), growth duration (0.4 or 4.0 Myr), and growth mode (linear or runaway). Our results show that larger planetesimals generally reach higher temperatures, but growth timing and mode significantly affect thermal evolution. Early accretion leads to higher temperatures, with some bodies reaching the Fe-FeS eutectic (1250 K), while delayed or prolonged growth reduces heating. Our results show that the constituent materials of Ryugu, which kept below 40 degC, likely formed near the surface of a hydrated mineral layer. This is possible even in planetesimals several hundred kilometers in size due to efficient heat transport via convection. If accretion begins 2.0 Myr after CAI and completes in 0.4 Myr, a wide region in such a body could yield Ryugu's material. - oai:arXiv.org:2512.07978v1 - astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + Tidal disruption event Calorimetry: Observational constraints on the physics of TDE optical flares + https://arxiv.org/abs/2512.09143 + arXiv:2512.09143v1 Announce Type: new +Abstract: Tidal disruption events are routinely discovered as bright optical/UV flares, the properties of which are now well categorized on the population level. The underlying physical processes that produce the evolution of their X-ray emission and their long-lasting UV/optical plateau are well understood; however, the origin of their early-time optical/UV emission remains the subject of much debate and uncertainty. In this paper we propose and perform ``Calorimetric'' tests of published theories of these optical flares, contrasting theoretical predictions for the scaling of the radiated energy and peak luminosity of these flares with black hole mass (something which is predicted by each theory), with the observed (positive) black hole mass scaling. No one theory provides a satisfactory description of observations at all black hole mass scales. Theories relating to the reprocessing of an Eddington-limited compact accretion disk, or emission (energy) released in the formation of a Keplerian disk near the circularisation radius, perform best, but require extending. Models whereby the optical/UV flare are directly produced by shocks between debris streams (e.g., TDEmass), or the efficient reprocessing of the fallback rate (e.g., MOSFIT, or any other model in which $L \propto \dot{M}_{\mathrm{fb}}$), are ruled out at high $(>5\sigma)$ significance by the data. + oai:arXiv.org:2512.09143v1 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Jun Kimura, Ryusei Satoh, Kentaro Terada, Sho Sasaki + Andrew Mummery, Brian Metzger, Sjoert van Velzen, Muryel Guolo - Was the Solar System's dynamical instability triggered by a (sub)stellar flyby? - https://arxiv.org/abs/2512.07979 - arXiv:2512.07979v1 Announce Type: new -Abstract: An instability among the giant planets' orbits can match many aspects of the Solar System's current orbital architecture. We explore the possibility that this dynamical instability was triggered by the close passage of a star or substellar object during the Sun's embedded cluster phase. We run N-body simulations starting with the giant planets in a resonant chain and an outer planetesimal disk, with a wide-enough planet-disk separation to preserve the planets' orbital stability for $>$100 Myr. We subject the system to a single flyby, testing a wide range in flyby mass, velocity and closest approach distance. We find a variety of outcomes, from flybys that over-excite the system (or strip the planets entirely) to flybys too weak to perturb the planets at all. An intermediate range of flybys triggers a dynamical instability that matches the present-day Solar System. Successful simulations -- that match the giant planets' orbits without over-exciting the cold classical Kuiper belt -- are characterized by the flyby of a substellar object ($3-30 M_{Jup}$) passing within 20 au of the Sun. We performed Monte Carlo simulations of the Sun's birth cluster phase, parameterized by the product of the stellar density $\eta$ and the cluster lifetime $T$. The balance between under- and over-excitation of the young Solar System is at $\eta T \approx 5 \times 10^4$~Myr pc$^{-3}$, in a range consistent with previous work. We find a probability of $\sim$1% that the Solar System's dynamical instability was triggered by a substellar flyby. The probability increases to $\sim$5% if the occurrence rate of free-floating planets and low-mass brown dwarfs is modestly higher than predicted by standard stellar initial mass functions. - oai:arXiv.org:2512.07979v1 + Modeling the meteoroid environment far from the ecliptic plane + https://arxiv.org/abs/2512.09171 + arXiv:2512.09171v1 Announce Type: new +Abstract: We describe a new version (numbered 3.1) of NASA's Meteoroid Engineering Model (MEM) in which we extend the model to handle locations that lie more than a few degrees in latitude off the ecliptic plane. We provide our algorithms for computing the spatial density and directionality of meteoroids far from the ecliptic and discuss their applications. In particular, we demonstrate how correct modeling of the out-of-ecliptic environment is critical for accurately assessing the risk posed by meteoroids to solar observation missions such as Solaris. + oai:arXiv.org:2512.09171v1 astro-ph.EP - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Sean N. Raymond, Nathan A. Kaib + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + 10.3847/PSJ/ae27cb + Althea V. Moorhead, Petr Pokorn\'y, Marcus A. Holden, William Kosmann - SAGAN-VI: When Jets Meet Filaments -- Environmental Imprints on the Growth of Giant Radio Galaxies - https://arxiv.org/abs/2512.07985 - arXiv:2512.07985v1 Announce Type: new -Abstract: Giant radio galaxies (GRGs) represent the largest individual astrophysical structures, rivalling galaxy clusters in physical extent. Understanding how they attain such scales demands examining their large scale cosmic surroundings, particularly the under explored filament environment. We quantify the three dimensional (3D) distance of GRGs from the nearest filament spine; test how this distance correlates with their growth and formation of different morphological classes; assess whether their radio jets exhibit preferred orientations relative to filament axes; and examine how filament anisotropy from spine to periphery modulates radio morphology. We employed a filament catalogue from the SDSS together with the largest GRG catalogue currently available. For each source, we measured the comoving distance to the nearest filament spine, the projected jet spine orientation angle, and quantified lobe asymmetry via the arm length ratio (ALR). These metrics trace proximity, directionality, and the impact of filamentary environment on morphology. We then compared GRGs with a control sample of small radio galaxies (SRGs) to constrain the environmental factors that regulate the attainment of giant sizes. We validated the robustness of our results via bootstrap resampling and non parametric statistical tests. Our results show that GRGs and SRGs have similar filament occupancy. By contrast, GRGs preferentially display larger alignment angles relative to filament spines, while SRG orientations are consistent with a random distribution. GRGs further show enhanced morphological asymmetry, reflected in lower ALR values than SRGs. Attainment of giant sizes is not governed by proximity to filaments; rather, it correlates with jet filament alignment. Abridged. - oai:arXiv.org:2512.07985v1 + TiNy Titans HI: Discovering Satellites via HI Gas in an Isolated, Compact Group of Dwarf Galaxies + https://arxiv.org/abs/2512.09174 + arXiv:2512.09174v1 Announce Type: new +Abstract: We report on the HI content of an isolated, compact group of 6 dwarf galaxies at a distance of 145 Mpc. The distribution and kinematics of the HI, including multiple gaseous bridges, indicate the group is a gravitationally bound system. The HI maps further reveal two newly discovered dwarf satellites easily identified by their gas but only barely visible in optical images. The four dwarf group members previously identified in SDSS have 9.06 < log(Mstar/Msun) < 9.43 and 9.42 < log(MHI/Msun) < 9.73. The two newly discovered dwarf satellites have log(Mstar/Msun) = 6.10 with log(MHI/Msun) = 8.71 and log(Mstar/Msun) = 7.07 with log(MHI/Msun) = 9.18. New Gemini optical spectra link the HI detections and their optical counterparts. The group's 3D velocity dispersion (188 km/s), mass-to-light ratio (M_L/B ~44), dynamical-to-baryonic mass ratio (Mdyn/Mbary ~ 21), size (69 kpc), and gas fraction (0.56) are all consistent with the compact dwarf groups in the TNG50 simulation. The group has a top-heavy satellite mass function that is inconsistent with predictions for LMC-sized hosts and may instead be two or more groups coming together. A Voronoi tessellation reveals the group resides in a tendril outside the intersection of two filaments. These intermediate density environments within large scale structure provide the conditions needed for groups of star forming, gas-rich dwarf galaxies to form and eventually merge. Our results further show that it is possible to uncover fainter dwarf satellites around dwarf galaxy hosts via HI maps. + oai:arXiv.org:2512.09174v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Mousumi Mahato, Elmo Tempel, Shishir Sankhyayan, Pratik Dabhade, Kshitij Chavan + http://creativecommons.org/licenses/by/4.0/ + Sabrina Stierwalt, Nicholas Luber, Zelie Goldberg Little, George C. Privon, Gurtina Besla, Kelsey E. Johnson, Nitya Kallivayalil, David R. Patton, Mary Putman, David Simpson Heil - Analytical Solutions for the Dynamics of Planetary Nebulae with and without Common Envelope Evolution - https://arxiv.org/abs/2512.07987 - arXiv:2512.07987v1 Announce Type: new -Abstract: We present new analytical solutions for the dynamics of planetary nebulae. These equations consider the temporal variation of the mechanical luminosity as well as the common envelope evolution scenario. By comparing a database of nebulae with these solutions, a large portion of planetary nebulae can be better explained by the common envelope evolution scenario, especially the fast and slow ones. Single AGB stellar models can only reproduce nebulae with expansion velocities between 20 and 30 km/s. - oai:arXiv.org:2512.07987v1 + iSTARMOD: A Python Code to Quantify Chromospheric Activity by Using the Spectral Subtraction Technique + https://arxiv.org/abs/2512.09192 + arXiv:2512.09192v1 Announce Type: new +Abstract: The use of the spectral subtraction technique allows measurements of chromospheric activity in late-type stars across several activity indicators, such as H$\alpha$ and the other Balmer lines in the visible, He I D3 and Na I D1, D2, Ca II H and K, and Ca II infrared triplet, as well as the Paschen series and He I $\lambda$10830 lines in the near-infrared. iSTARMOD is an updated and extended version of the original STARMOD code and its subsequent modifications. iSTARMOD is presented in this paper as a Python code developed to quantify chromospheric activity by using the spectral subtraction technique. iSTARMOD improves usability, modularity, and integration with modern data analysis workflows and is publicly available, including several examples that help one learn how to use and test the code. The iSTARMOD code is accompanied here with a series of calibrations of $\chi$-functions, to transform the excess emission equivalent widths measured through iSTARMOD into absolute surface fluxes. The method provided with this code and the corresponding flux calibrations allows for the automatic characterization of the chromospheric activity of a large number of spectra or a large number of stars and is also very useful for mitigating the effect of activity on radial velocities in the search for exoplanets. + oai:arXiv.org:2512.09192v1 astro-ph.SR - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.EP + astro-ph.IM + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/publicdomain/zero/1.0/ - G. Garcia-Segura + http://creativecommons.org/licenses/by/4.0/ + 10.3847/1538-3881/ae173e + The Astronomical Journal AJ 171 15 (2026) + Fernando Labarga, David Montes - Can meridional flow variations explain the observed rising/declining phase asymmetry in the solar cycle? - https://arxiv.org/abs/2512.07989 - arXiv:2512.07989v1 Announce Type: new -Abstract: Accurate prediction of the 11-year solar cycle remains a major challenge in solar physics and is important for space weather forecasting. A persistent property of the cycle is its asymmetry: the rise phase is usually much shorter than the decay phase. This asymmetry is often linked to variations in the Sun's meridional circulation, but it is unclear whether these variations are mainly deterministic, produced by Lorentz-force feedback, or stochastic in nature. We investigate this question using kinematic flux-transport dynamo simulations that include three types of time-dependent meridional flow: deterministic variations, stochastic fluctuations, and hybrid combinations of both. We evaluate cycle asymmetry using the ratio of rise to decay times and correlations of cycle amplitude with rise time, rise rate, and decay rate. Our results show that the temporal evolution of the meridional flow strongly controls cycle asymmetry. When both the meridional circulation and the Babcock-Leighton mechanism vary stochastically, the model does not produce cycles in which the decay phase is consistently longer than the rise phase. In contrast, deterministic variations motivated by Lorentz-force feedback and linked to the latitude of maximum toroidal field reproduce the observed asymmetry. In these cases, the meridional flow weakens near cycle maximum, stays reduced for some time, and then recovers, producing a longer decay phase. Hybrid models that mix deterministic and stochastic variability also match the observed rise-decay asymmetry. Across all simulations, cycle amplitude correlates strongly with rise rate, while correlations with rise time and decay rate are weaker but remain significant. These results highlight the key role of meridional flow variability in shaping solar cycle asymmetry and show that incorporating such variability can improve forecasting tools such as Solar Predict. - oai:arXiv.org:2512.07989v1 + Double tidal disruption events or repeating partial tidal disruption events in AT 2020vdq + https://arxiv.org/abs/2512.09204 + arXiv:2512.09204v1 Announce Type: new +Abstract: AT 2020vdq has been known as a candidate of repeating partial tidal disruption events (pTDEs), due to its two flares with a time interval of $\sim$1000 days. Here, a simplified method is proposed to test such repeating pTDEs scenario considering a main-sequence star tidally disrupted twice. For the two flares in AT 2020vdq if related to the repeating pTDEs scenario, theoretical TDE model determined stellar mass of the original star disrupted for the first flare should be not very different from the mass of the star (to trace the reminder of the original star) disrupted for the second flare, because a partial TDE with impact parameter $\beta$ smaller than 1 can lead to most of (probable higher than 90\%) the stellar mass also bound to the reminder of the original star. After considering theoretical TDE model applied to describe the two flares in AT 2020vdq, the model determined stellar masses are about 2${\rm M_\odot}$ and $0.36{\rm M_\odot}$ for the stars disrupted in the first flare and the second flare. The large mass difference cannot be reasonably expected by the repeating pTDEs with $\beta$ around 0.6 in AT 2020vdq. The results in this manuscript indicate that the repeating pTDEs scenario is not preferred at current stage in AT 2020vdq, but the probable double TDEs for two individual stars tidally disrupted should be currently recommended. + oai:arXiv.org:2512.09204v1 + astro-ph.GA + astro-ph.HE astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Soumitra Hazra, Allan Sacha Brun, Laurene Jouve + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Zhang XueGuang (GXU) - The Drivers of the Decline in Supermassive Black Hole Growth at $z<2$ - https://arxiv.org/abs/2512.08004 - arXiv:2512.08004v1 Announce Type: new -Abstract: It is well established that cosmic supermassive black hole (SMBH) growth peaks at $z\approx1.5-2$, followed by a strong decline of $\approx1-1.5\,\rm dex$ toward the present day, with the comoving number density of higher-luminosity active galactic nuclei (AGNs) peaking at higher redshift (referred to as "AGN downsizing"). We leverage the best current measurements of the SMBH accretion distribution, based upon data from nine well-characterized extragalactic fields with a "wedding-cake" design, to investigate and quantify the drivers of the drastic decline in cosmic SMBH growth. The decline in the typical Eddington ratio ($\lambda_\mathrm{Edd}$) of AGNs (decreasing by $\approx1.35\,\rm dex$ from $z\approx1.5-2$ to $z\approx0.2$) is the dominant driver for the broad decline in SMBH growth, rather than a shift of accretion activity to less-massive SMBHs. As $\lambda_\mathrm{Edd}$ decreases toward lower redshift, the primary contributor to the cosmic SMBH accretion density ($\rho_\mathrm{BHAR}$) has shifted from high-$\lambda_\mathrm{Edd}$ AGNs to low-$\lambda_\mathrm{Edd}$ AGNs, even though the latter always dominate the comoving AGN number density at $z<4$. We also find that the decline in SMBH growth toward lower SMBH mass in less-massive galaxies is primarily due to the decreasing outburst luminosity rather than the duty cycle. - oai:arXiv.org:2512.08004v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Delving into the depths of NGC 3783 with XRISM IV. Mapping of the accretion flow with Fe K$\alpha$ emission lines + https://arxiv.org/abs/2512.09207 + arXiv:2512.09207v1 Announce Type: new +Abstract: Using XRISM/Resolve $439 \, \rm ks$ time-averaged spectra of the well-known Seyfert-1.5 active galactic nucleus (AGN) in NGC 3783, we investigate the nature of the Fe K$\alpha$ emission line at 6.4 keV, the strongest and most common X-ray line observed in AGN. Even the narrow component of the line is resolved with evident Fe K$\alpha_{1}$ (6.404 keV) and K$\alpha_{2}$ (6.391 keV) contributions in a 2:1 flux ratio, fully consistent with a neutral gas with negligible bulk velocity. The narrow and intermediate-width components have a full-width at half maximum (FWHM) of 350 $\pm$ 50 km/s and $3510 \pm 470 \, \rm km/s$, respectively, suggesting that they arise in the outer disk/torus and/or BLR. We detect a $10\%$ excess flux around 4 $-$ 7 keV that is not well described by a symmetric Gaussian line, but is consistent with a relativistically broadened emission line. In this paper, we take the simplest approach to model the asymmetric line as a single emission line (assuming either neutral, He-like or H-like iron) convolved with a relativistic disk line model. As expected, the inferred inclination angle is highly sensitive to the assumed ionization state, and ranges between $i=17-44^{ \circ}$. This model also constrains the black hole spin via the extent of the red wing: the required gravitational redshift in the fitted disk-line profile disfavors a non-spinning (Schwarzschild) black hole. The derived inner radius is close to the radius of the innermost stable circular orbit $r_{\rm ISCO}$ and strongly correlated with the black hole spin. To better constrain the spin, we fix the inner radius at $r_{\rm ISCO}$ and derive a lower limit on the spin of $a \ge 0.29$ at the 3 $\sigma$ confidence level. A Compton shoulder is detected in our data as well as a $2-3 \, \sigma$ detection of the Cr K$\alpha$ and Ni K$\alpha$ lines. + oai:arXiv.org:2512.09207v1 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Chen Li, Jelle S. Kaastra, Liyi Gu, Missagh Mehdipour, Megan E. Eckart, Matteo Guainazzi, Erin Kara, Laura W. Brenneman, Misaki Mizumoto, Jon Miller, Keigo Fukumura, Ehud Behar, Christos Panagiotou, Matilde Signorini, Keqin Zhao, Ralf Ballhausen, Camille M. Diez, Timothy R. Kallman, Shoji Ogawa, Atsushi Tanimoto, Yoshihiro Ueda + + + Frequency- and phase-resolved polarimetry of millisecond pulsars and its application to timing + https://arxiv.org/abs/2512.09220 + arXiv:2512.09220v1 Announce Type: new +Abstract: Pulsar timing is used for a variety of applications including tests of fundamental physics, probing the structure of neutron stars, and detecting nanohertz gravitational waves. Development of robust methods and generation of high-quality timing data is therefore of utmost importance. In this paper, we present a new technique for creating high-fidelity templates that can be used to measure the pulse times of arrival with significantly increased precision compared to existing methods. Our framework makes use of all available polarimetric information to generate frequency-dependent models of pulse-shape evolution of all four Stokes parameters. We apply this method to millisecond pulsars observed by the Parkes Pulsar Timing Array and show that it results in timing measurement uncertainties reduced up to $\sim$20-30\%. We also present, for the first time, phase- and frequency-resolved polarimetric measurements of millisecond pulsars observed with the Parkes Murriyang ultra-widebandwith-low receiver. The data, plots and the code underlying this analysis are made publicly available. + oai:arXiv.org:2512.09220v1 + astro-ph.HE + astro-ph.IM + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by-sa/4.0/ - 10.3847/1538-4357/ae173d - Zhibo Yu, W. N. Brandt, Fan Zou, Bin Luo, Qingling Ni, D. P. Schneider, Fabio Vito + Ma{\l}gorzata Cury{\l}o, Andrew Zic, Shuangqiang Wang, Eric Thrane, Paul D. Lasky, Jacob Cardinal Tremblay, Zu-Cheng Chen, Shi Dai, Valentina Di Marco, George Hobbs, Agastya Kapur, Wenhua Ling, Marcus E. Lower, Saurav Mishra, Daniel J. Reardon, Christopher J. Russell, Ryan M. Shannon, Xing-Jiang Zhu - The GLEAM 4-Jy (G4Jy) Sample: IV. Multiwavelength data and analysis - https://arxiv.org/abs/2512.08008 - arXiv:2512.08008v1 Announce Type: new -Abstract: We provide an updated 'multiwavelength' version of the G4Jy catalogue (available at https://github.com/svw26/G4Jy, https://zenodo.org/communities/g4jy/records, and through VizieR), which has 127 new host-galaxy identifications, as described in Paper III of this paper series. We also supplement the redshift information (0.0 < z < 3.6) gathered in Paper III with $griz$ photometry available through DR10 of the DESI Legacy Surveys. Together, this legacy dataset allows us to investigate the multiwavelength properties of these southern radio-bright galaxies, which includes an initial analysis of radio spectral-curvature for this complete sample (S_151MHz > 4 Jy). For example, we present (for the first time in the literature) the radio-power--size diagram as a function of radio spectral-curvature, [P--D](SCI), noting that the spectral-curvature index (SCI) can act as a proxy for the spectral age of the radio source. This radio-power--size--age diagram shows an interesting predominance of candidate remnant radio-galaxies (SCI > 0.15) with D < 200 kpc (although these may instead be young radio-sources), and a vast range of linear sizes for candidate restarted radio-galaxies (SCI < -0.15). We also show that (i) G4Jy sources populate the entirety of WISE colour-colour space, (ii) optically point-like sources (i.e. candidate quasars) are brighter than the well-studied K--z relation (as expected), and (iii) there is no relation between the SCI of the radio source and its host-galaxy properties. - oai:arXiv.org:2512.08008v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + An extragalactic gamma-ray binary formed in supernova 2022jli + https://arxiv.org/abs/2512.09223 + arXiv:2512.09223v1 Announce Type: new +Abstract: On May 5 2022, a type Ic supernova (SN) explosion SN~2022jli was discovered. This SN showed additional optical emissions, which were found to exhibit 12.4-day periodic undulations and concordant periodic velocity shifts. These key features likely indicate a compact object in a binary system was formed. A faint $\gamma$-ray source was also detected at the position of the SN and upon checking the $\gamma$-ray photons' arrival times, it was revealed that the same 12.4-day periodicity was likely present. Here we report our detailed analysis results for the $\gamma$-ray source. Not only was the $\gamma$-ray emission detectable for $\sim$1.5\,years since the discovery time, but a strong modulation at period 12.5\,day was also clearly determined. Considering the newly formed compact object to be a neutron star or a stellar-mass black hole, the putative binary, having an orbital period of 12.5\,day, is likely the first extragalactic high-energy system detected. The system may serve as a valuable example for the formation of many such binaries observed in the Milky Way and nearby galaxies. + oai:arXiv.org:2512.09223v1 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by/4.0/ + Pengfei Zhang (Yunnan University, China), Zhongxiang Wang (Yunnan University, China), Shunhao Ji (Yunnan University, China) + + + Tracing a Multi-Temperature Quiescent Prominence's Thermodynamic Evolution from Sun to Earth + https://arxiv.org/abs/2512.09234 + arXiv:2512.09234v1 Announce Type: new +Abstract: Solar prominences are cool, dense stable structures routinely observed in the corona. Prominences are often ejected from the Sun via coronal mass ejections (CMEs). However, they are rarely detected in a cool, low-ionized state within CMEs measured in situ, making their evolution hard to study. We examine the thermodynamic evolution of one of these rare cases where a quiescent prominence eruption clearly preserves its low-ionized charge state as evidenced by in situ detection. We use multi-viewpoint Extreme Ultraviolet (EUV) observations to track and estimate the density, temperature and speed of the prominence as it erupts. We observe that part of the prominence remains in absorption well beyond initial liftoff, indicating the bulk of the prominence experiences minimal ionization and suggesting any strong heating is balanced by radiative losses, expansion, or conduction. From its subsequent in situ passage near 1au, charge states reveal that the prominence is composed of both cool, low-ionized ions as well as hotter plasma reflected by the presence of highly ionized iron, Fe$^{16+}$. Simulated non-equilibrium ionization and recombination results using observationally derived initial conditions match the in situ multi-thermal state for a prominence composed of 70% cool plasma with a 1.8MK peak temperature, and 30% hot plasma with a 4.3MK peak temperature. This suggests that the prominence may not be heated uniformly or that parts of it cools more rapidly. The complex, multi-thermal nature of this erupting prominence emphasizes the need for more comprehensive spectral observations of the global corona. + oai:arXiv.org:2512.09234v1 + astro-ph.SR + physics.plasm-ph + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Sarah V. White, Precious K. Sejake, Kshitij Thorat, Heinz Andernach, Thomas M. O. Franzen, O. Ivy Wong, Anna D. Kapinska, Joseph R. Callingham, Christopher J. Riseley, Nick Seymour, Randall Wayth, Lister Staveley-Smith, Rajan Chhetri, Natasha Hurley-Walker, John Morgan, Paul Hancock, Francesco Massaro, Abigail Garcia-Perez, Ana Jimenez-Gallardo, Harold A. Pena-Herazo + Callie A. Garc\'ia, Yeimy J. Rivera, Samuel T. Badman, John C. Raymond, Katharine K. Reeves, Tatiana Niembro, Kristoff W. Paulson, Michael L. Stevens - UVOIR spectrum, X-ray emission, and proper motion of the isolated neutron star RX J2143.0+0654 - https://arxiv.org/abs/2512.08033 - arXiv:2512.08033v1 Announce Type: new -Abstract: We observed the isolated neutron star RX J2143.0+0654 with the Hubble Space Telescope (HST) in the UVOIR wavelength range (0.14-1.7 $\mu$m). The UV part is consistent with a Rayleigh-Jeans tail of a thermal spectrum, $f_\nu\propto \nu^2$, while a power-law spectrum, $f_\nu \propto \nu^\alpha$ with $\alpha \sim -0.8$, dominates in the NIR-optical. A joint fit of the UVOIR and contemporaneous X-ray spectra with a two-component blackbody with possible absorption features + power-law optical spectrum yields the following temperature and apparent radius of the colder component (which gives the main contribution in the UV): $kT_{\rm cold}\approx 45$ eV, $R_{\rm cold}\approx 6 d_{260}$ km, where $d_{260}$ is the distance in units of 260 pc. The temperature and radius of the hotter component, $kT_{\rm hot}\approx 106$ eV and $R_{\rm hot} \approx 1.5d_{260}$ km, the parameters of an absorption feature at 0.74 keV, and the properties of X-ray pulsations, are the same as found in previous X-ray observations. In the NIR images the neutron star is possibly surrounded by extended emission with a characteristic size of $\sim 2''$ and flux densities of about 1.7 and 0.9 $\mu$Jy at 1.54 and 1.15 $\mu$m, respectively. Comparison with a previous HST observation in the optical 14 years ago shows a proper motion $\mu\approx 6$ mas yr$^{-1}$, which corresponds to a small transverse velocity of $7d_{260}$ km s$^{-1}$. It is consistent with the hypothesis that the neutron star was born in the vicinity of the solar system about 0.5 Myr ago. - oai:arXiv.org:2512.08033v1 + The ONs and OFFs of Pulsar Radio Emission: Characterizing the Nulling Phenomenon + https://arxiv.org/abs/2512.09274 + arXiv:2512.09274v1 Announce Type: new +Abstract: Radio emission from pulsars is known to exhibit a diverse range of emission phenomena, among which nulling, where the emission becomes temporarily undetectable, is an intriguing one. Observations suggest nulling is prevalent in many long-period pulsars and must be understood to obtain a more comprehensive picture of pulsar emission and its evolution. One of the limitations in observational characterisation of nulling is the limited signal-to-noise, making individual pulses often not easily distinguishable from noise or any putative faint emission. Although some of the approaches in the published literature attempt to address this, they lose efficacy when individual pulses appear indistinguishable from the noise, and as a result, can lead to less accurate measurements. Here we develop a new method (the $\mathbb{N}$sum algorithm) that uses sums of pulses for better distinguishability from noise and thus measures the nulling fraction more robustly. It can be employed for measuring nulling fractions in weaker pulsars and observations with a limited number of observed pulses. We compare our algorithm with the recently developed Gaussian Mixture Modelling approach, using both simulated and real data, and find that our approach yields consistent results for generic and weaker pulsars. We also explore quasi-periodicity in nulling and measure the related parameters for five pulsars, including PSRs~J1453$-$6413, J0950$+$0755 and J0026$-$1955, for which these are also the first such measurements. We compare and contrast our analysis of quasi-periodic nulling with previously published work and explore the use of spin-down energy loss ($\dot E$) to distinguish between different types of modulation behaviour. + oai:arXiv.org:2512.09274v1 astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + physics.data-an + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.3847/1538-4357/ae1efa - George G. Pavlov (Pennsylvania State University), Vadim Abramkin (Independent Researcher), B. Posselt (University of Oxford, Pennsylvania State University) + Garvit Grover, N. D. Ramesh Bhat, Samuel J. McSweeney, Christopher P. Lee, Chia Min Tan, Shih Ching Fu, Bradley W. Meyers - Spatially Resolved Physical Properties of Young Star Clusters and Star-forming Clumps in the Brightest z>6 Galaxy, the Strongly Lensed Cosmic Spear at z=6.2 - https://arxiv.org/abs/2512.08054 - arXiv:2512.08054v1 Announce Type: new -Abstract: We present spatially resolved analysis of stellar populations in the brightest $z>6$ galaxy known to date (AB mag 23), the strongly lensed MACS0308$-$zD1 (dubbed the ``Cosmic Spear'') at $z_{\rm spec}=6.2$. New JWST NIRCam imaging and high-resolution NIRSpec IFU spectroscopy span the rest-frame ultraviolet to optical. The NIRCam imaging reveals bright star-forming clumps and a tail consisting of three distinct, extremely compact star clusters that are multiply-imaged by gravitational lensing. The star clusters have effective radii of $R_{\rm{eff}} \sim 5$ pc, stellar masses of $M_{*} \sim 10^{6}-10^{7}\,M_{\odot}$, and high stellar mass surface densities of $\Sigma_{*} > 10^{4}\,M_{\odot}~\rm{pc}^{-2}$. While their stellar populations are very young ($\sim 5-9$ Myr), their dynamical ages exceed unity, consistent with the clusters being gravitationally bound systems. Placing the star clusters in the size vs.~stellar mass density plane, we find they occupy a region similar to other high-redshift star clusters within galaxies observed recently with JWST, being significantly more massive and denser than local star clusters. Spatially resolved analysis of the brightest clump reveals a compact, intensely star-forming core. The ionizing photon production efficiency ($\xi_{\rm{ion}}$) is slightly suppressed in this central region, potentially indicating a locally elevated Lyman continuum escape fraction facilitated by feedback-driven channels. - oai:arXiv.org:2512.08054v1 + Deblending the MIGHTEE-COSMOS survey with XID+: The resolved radio source counts to $S_{1.4}\approx 5\mu$Jy + https://arxiv.org/abs/2512.09290 + arXiv:2512.09290v1 Announce Type: new +Abstract: Deep radio continuum surveys provide fundamental constraints on galaxy evolution, but source confusion limits sensitivity to the faintest sources. We present a complete framework for producing high-fidelity deblended radio catalogs from the confused MIGHTEE maps using the probabilistic deblending framework XID+ and prior positions from deep multi-wavelength data in the COSMOS field. To assess performance, we construct MIGHTEE-like simulations based on the Tiered Radio Extragalactic Continuum Simulation (T-RECS) radio source population, ensuring a realistic distribution of star-forming galaxies and active galactic nuclei (AGN) for validation. Through these simulations, we show that prior catalog purity is the dominant factor controlling deblending accuracy: a high-purity prior, containing only sources with a high likelihood of radio detection, recovers accurate flux densities and reproduces input source counts down to $\sim 3\sigma$ (where $\sigma = $ thermal noise). On the other hand, a complete prior overestimates the source counts due to spurious detections. Our optimal strategy combines the high-purity prior with a mask that removes sources detected above $50~\mu$Jy. Applied to the $\sim$1.3\,deg$^2$ area of the MIGHTEE-COSMOS field defined by overlapping multi-wavelength data, this procedure yields a deblended catalog of 89,562 sources. The derived 1.4\,GHz source counts agree with independent P(D) analyses and indicate that we resolve the radio background to $\sim 4.8\,\mu$Jy. We also define a recommended high-fidelity sample of 20,757 sources, based on detection significance, flux density, and goodness-of-fit, which provides reliable flux densities for individual sources in the confusion-limited regime. + oai:arXiv.org:2512.09290v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Eliab D. Malefahlo, Matt J. Jarvis, Mario G. Santos, Catherine Cress, Daniel J. B. Smith, Catherine Hale, Jos\'e Afonso, Imogen H. Whittam, Mattia Vaccari, Ian Heywood, Shuowen Jin, Fangxia An + + + Galaxy Cluster Detection and Dynamical Analysis in the VIPERS High-Redshift Spectroscopic Survey + https://arxiv.org/abs/2512.09303 + arXiv:2512.09303v1 Announce Type: new +Abstract: We present a dynamical analysis of galaxy clusters identified in the VIPERS spectroscopic survey within the redshift range 0.5 <= z <= 1.2. Cluster candidates were first detected as overdense regions in redshift space through the Finger-of-God (FoG) effect, and cluster membership was assigned using the GalWeight technique within the FoG-GalWeight methodology developed by our team. For each cluster, we derived the virial radius (R200), velocity dispersion (sigma200), and virial mass (M200) using the virial mass estimator. We identified ten VIPERS clusters spanning a mass range of 0.59 x 10^14 <= M200/(h^-1 Msun) <= 4.32 x 10^14 and velocity dispersions of 360 <= sigma200 <= 900 km s^-1. We cross-matched the VIPERS clusters with published catalogs and found at least one matching system for each cluster, offering external validation for our detections. We investigated the velocity dispersion-mass relation for these systems and obtained log(sigma200) = (2.73 +/- 0.06) + (0.36 +/- 0.18) log(M200), with an intrinsic scatter of sigma_int = 0.04 +/- 0.07. The derived relation is consistent with theoretical predictions from N-body and hydrodynamical simulations, confirming the reliability of the FoG-GalWeight methodology and the robustness of the virial mass estimator. Our findings demonstrate that the velocity dispersion can serve as a reliable and direct proxy for cluster mass, even at high redshift, without requiring additional dynamical mass modeling. + oai:arXiv.org:2512.09303v1 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Abdurro'uf, Dan Coe, Tom Resseguier, Calla Murphy, Xinfeng Xu, Angela Adamo, Namrata Roy, Alaina Henry, Vasily Kokorev, Gabriel Brammer, Seiji Fujimoto, Henry C. Ferguson, Amanda Pagul, Rogier A. Windhorst, Timothy Heckman, Jose M. Diego, Hollis B. Akins, Joseph Allingham, Ricardo O. Amor\'in, Danielle A. Berg, Maru\v{s}a Brada\v{c}, Larry D. Bradley, Wenlei Chen, John Chisholm, Christopher J. Conselice, Pratika Dayal, Miroslava Dessauges-Zavadsky, Andreas L. Faisst, Steven L. Finkelstein, Yoshinobu Fudamoto, Lukas J. Furtak, Yuichi Harikane, Tiger Yu-Yang Hsiao, Yolanda Jimenez-Teja, Anton M. Koekemoer, Rebecca L. Larson, Ray A. Lucas, Matteo Messa, Lamiya Mowla, Minami Nakane, Ga\"el Noirot, Richard Pan, Massimo Pascale, Johan Richard, Massimo Ricotti, Luke Robbins, Daniel Schaerer, Fengwu Sun, Eros Vanzella, Brian Welch, Chris Willott, Adi Zitrin + Mohamed H. Abdullah, Omnia I. Adly, Gillian Wilson, Magdy Y. Amin, A. Ahmed - The Two-Infall Model Revisited: Constraints on Milky Way Bulge Assembly from >30,000 Galactic Chemical Evolution Models and Machine Learning - https://arxiv.org/abs/2512.08090 - arXiv:2512.08090v1 Announce Type: new -Abstract: We constrain the formation history of the Milky Way bulge using a two-infall Galactic Chemical Evolution (GCE) framework implemented in the OMEGA++ code. We recover a best-fit scenario in which the bulge forms through an early, rapid starburst (t1 ~ 0.1Gyr, tau1 ~ 0.09Gyr, star-formation efficiency (SFE) ~ 3Gyr^-1 followed by a delayed, lower mass second infall (t2 ~ 5.1Gyr, tau2 ~ 1.7Gyr, sigma2 ~ 0.69). Our model adopts mass- and metallicity-dependent nucleosynthetic yields from modern stellar grids and explores a wide GCE parameter space in infall timing, star formation efficiency, mass partitioning, IMF upper mass, and SN Ia normalization, optimized via a hybrid genetic algorithm with MCMC refinement. The later infall features a reduced star formation efficiency (Delta SFE ~ 0.72), reproducing the metal-rich peak of the bulge metallicity distribution function (MDF) and the decline in [alpha/Fe] at high [Fe/H]. Our model naturally favors the Joyce et al. (2023) age--metallicity relation over the ages in Bensby et al. (2017). Degeneracy and principal component analysis show that the infall history, SFE, and mass partitioning are strongly covariant -- the bulge's observed MDF, abundance trends, and age distribution constrain only their combinations, not each parameter independently. The results support a composite bulge origin -- a classical collapse builds the majority of the mass, while a younger component is required to match the late stage enrichment. - oai:arXiv.org:2512.08090v1 + Four Giant Planets from 2024 KMTNet Microlensing Campaign + https://arxiv.org/abs/2512.09325 + arXiv:2512.09325v1 Announce Type: new +Abstract: In this work, we present analyses of four newly discovered planetary microlensing events from the 2024 KMTNet survey season: KMT-2024-BLG-0176, KMT-2024-BLG-0349, KMT-2024-BLG-1870, and KMT-2024-BLG-2087. In each case, the planetary nature was revealed through distinct types of anomalies in the lensing light curves: a positive bump near the peak for KMT-2024-BLG-0176, an asymmetric peak for KMT-2024-BLG-0349, a short-duration central dip for KMT-2024-BLG-1870, and a caustic-crossing feature for KMT-2024-BLG-2087. Detailed modeling of the light curves confirms that these anomalies are produced by planetary companions with planet-to-host mass ratios in the range of $(1.5\text{--}17.9)\times 10^{-3}$. Despite the diversity of signal morphologies, all planets detected in these events are giant planets with masses comparable to or exceeding that of Jupiter in the Solar System. Each planet orbits a host star less massive than the Sun, emphasizing the strength of microlensing in uncovering planetary systems around low-mass stellar hosts. + oai:arXiv.org:2512.09325v1 + astro-ph.EP astro-ph.GA - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by/4.0/ + Cheongho Han, Andrzej Udalski, Ian A. Bond, Chung-Uk Lee, Jiyuan Zhang, Michael D. Albrow, Sun-Ju Chung, Andrew Gould, Youn Kil Jung, Kyu-Ha Hwang, Yoon-Hyun Ryu, Yossi Shvartzvald, In-Gu Shin, Jennifer C. Yee, Weicheng Zang, Hongjing Yang, Doeon Kim, Dong-Jin Kim, Byeong-Gon Park, Przemek Mr\'oz, Micha{\l} K. Szyma\'nski, Jan Skowron, Rados{\l}aw Poleski, Igor Soszy\'nski, Pawe{\l} Pietrukowicz, Szymon Koz{\l}owski, Krzysztof A. Rybicki, Patryk Iwanek, Krzysztof Ulaczyk, Marcin Wrona, Mariusz Gromadzki, Mateusz J. Mr\'oz, Fumio Abe, David P. Bennett, Aparna Bhattacharya, Ryusei Hamada, Stela Ishitani Silva, Yuki Hirao, Asahi Idei, Shota Miyazaki, Yasushi Muraki, Tutumi Nagai, Kansuke Nunota, Greg Olmschenk, Cl\'ement Ranc, Nicholas J. Rattenbury, Yuki Satoh, Takahiro Sumi, Daisuke Suzuki, Takuto Tamaoki, Sean K. Terry, Paul J. Tristram, Aikaterini Vandorou, Hibiki Yama, Yuchen Tang, Yunyi Tang, Shude Mao, Dan Maoz, Wei Zhu + + + Discovery of the redback millisecond pulsar PSR J1728-4608 with ASKAP + https://arxiv.org/abs/2512.09339 + arXiv:2512.09339v1 Announce Type: new +Abstract: We present the discovery of PSR J1728-4608, a new redback spider pulsar identified in images from the Australian SKA Pathfinder telescope. PSR J1728-4608 is a millisecond pulsar with a spin period of 2.86 ms, in a 5.05 hr orbit with a companion star. The pulsar exhibits a radio spectrum of the form $S_\nu \propto \nu^\alpha$, with a measured spectral index of $\alpha = -1.8(3)$. It is eclipsed for 42% of its orbit at 888 MHz, and multi--frequency image--domain observations show that the egress duration scales with frequency as a power law with index $n = -1.74$, where longer duration eclipses are seen at lower frequencies. An optical counterpart is detected in archival Gaia data within $0.5''$ of the radio position. It has a mean G-band magnitude of 18.8 mag and its light curve displays characteristics consistent with a combination of ellipsoidal modulation and irradiation effects. We also report the nearest Fermi $\gamma$-ray source, located 2$'$ away from our source, as a possible association. A radio timing study constrains the intrinsic and orbital properties of the system, revealing orbital period variations that we attribute to changes in the gravitational quadrupole moment of the companion star. At the eclipse boundary, we measure a maximum dispersion measure excess of $2.0 \pm 1.2 \ \mathrm{pc\ cm^{-3}}$, corresponding to an electron column density of $5.9 \pm 3.6 \times10^{18} \ \mathrm{cm^{-2}}$. Modelling of the eclipse mechanism suggests that synchrotron absorption is the dominant cause of the eclipses observed at radio wavelengths. The discovery and characterisation of systems like \psr\ provide valuable insights into pulsar recycling, binary evolution, the nature of companion-driven eclipses, and the interplay between compact objects and their plasma environments. + oai:arXiv.org:2512.09339v1 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Niall Miller, Meridith Joyce, Christian I. Johnson, Jamie Tayar, Thomas Trueman, R Michael Rich + manuscript ID PAS-2025-0177.R3 + F. Petrou, Y. Wang, N. Hurley-Walker, S. McSweeney, L. Zhang, R. G. Key, J. Freeburn, B. W. Meyers, David L. Kaplan, A. Zic, Tara Murphy, D. Dobie, Y. Maan - The SOFIA Massive(SOMA)Radio Survey. III. Radio Emission from Intermediate-Mass Protostars - https://arxiv.org/abs/2512.08105 - arXiv:2512.08105v1 Announce Type: new -Abstract: We present results from Very Large Array (VLA) radio continuum observations of twelve intermediate-mass (IM) protostars, as part of the \textit{SOFIA} Massive Star Formation Survey. Using these observations, we studied their morphology, multiplicity and radio spectral energy distributions (SEDs). Across our target regions, we resolve multiple compact sources and report eight new detections, four of which are entirely new and four that have counterparts at other wavelengths, but are detected here for the first time at radio frequencies. Based on radio morphologies and spectral indices, we assess the nature of the detected sources, highlighting seven that display jet-like structures and spectral indices consistent with ionized jets. Combining our results with the SOMA Radio I and II results, we expand the overall sample to 29 protostars, covering a bolometric luminosity range from $L_{\rm bol}\sim 10^2$ to $10^6\:L_\odot$. These sources help define a potential evolutionary sequence in the radio versus bolometric luminosity diagram. IM protostars have radio luminosities that are lower than expected from a simple power law extrapolation from low-mass protostars. However, this result is consistent with theoretical expectations from protostellar evolution models, which show low levels of photoionization and reduced shock ionization emission due to expanded stellar radii during this phase. Overall our expanded SOMA Radio sample provides new constraints on theoretical models of massive protostellar evolution, especially the connection to ionized gas structures. - oai:arXiv.org:2512.08105v1 - astro-ph.SR + The stellar and dark matter distributions in elliptical galaxies measured by stacked weak gravitational lensing + https://arxiv.org/abs/2512.09342 + arXiv:2512.09342v1 Announce Type: new +Abstract: We investigate stellar mass and central dark matter density profiles of photometric luminous red galaxies with stellar masses of $\sim10^{10}-10^{12}M_\odot$ using weak gravitational lensing measurements from the Hyper Suprime-Cam Subaru Strategic Program data obtained with the Subaru Telescope. By stacking weak lensing signals from a large number of galaxies, we obtain average tangential shear profiles down to $\sim 10\,\mathrm{kpc}/h$, which are fitted assuming a two-component model consisting of stellar and dark matter components to constrain their central dark matter distribution. We find a preference for non-zero core radii of dark matter distributions in galaxies with stellar masses of $\sim 10^{11}M_\odot$. Our results imply a stronger feedback effect than that typically predicted by current hydrodynamical simulations. In addition, we provide a new constraint on the stellar-to-halo mass relation, where both stellar and halo masses are, for the first time, directly constrained by weak gravitational lensing. Our results prefer the stellar initial mass function (IMF) that is more bottom-heavy than the Salpeter IMF. + oai:arXiv.org:2512.09342v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Francisco Sequeira-Murillo, Viviana Rosero, Joshua Marvil, Jonathan C. Tan, Ruben Fedriani, Yichen Zhang, Prasanta Gorai, James M. De Buizer, Maria T. Beltr\'an + Momoka Fujikawa, Masamune Oguri - The MAGPI Survey: forward modelled gas-phase metallicity gradients in galaxies at $z\sim 0.3$ - https://arxiv.org/abs/2512.08112 - arXiv:2512.08112v1 Announce Type: new -Abstract: We measure the seeing-deconvolved gas-phase metallicity gradients of 70 star-forming galaxies at $z\sim 0.3$ from the MAGPI survey and investigate their relationship with galaxy properties to understand the mechanisms that influence the distribution of metals and shape the evolution of the galaxies. We use a Bayesian modelling technique, Blobby3D, which accounts for seeing effects (beam smearing) and can model the substructures of the flux distribution. The median metallicity gradient of our sample is $\nabla \mathrm{[O/H]}=-0.013^{+0.059}_{-0.033}$ dex/kpc. Among the galaxies in our sample, 32.9% have negative metallicity gradients (2$\sigma$ significance), 10.0% have positive gradients and 57.1% have flat gradients. The $\nabla \mathrm{[O/H]}$-$M_*$ relation of the MAGPI galaxies generally agrees with theoretical predictions, where a combination of stellar feedback, gas transport, and accretion shapes the metallicity profile, with the dominant processes varying with galaxy mass. We find a positive correlation between $\nabla \mathrm{[O/H]}$ and gas velocity dispersion ($r=0.36$), indicating that stronger gas turbulence is associated with flatter or inverted metallicity gradients, likely due to enhanced gas mixing. Additionally, smaller galaxies tend to have flatter or positive gradients, suggesting that metal dilution by gas accretion or removal via feedback-driven winds may outweigh metal enrichment in small galaxies. - oai:arXiv.org:2512.08112v1 + Bimetric MOND as a framework for variable-$G$ theories -- local systems and cosmology + https://arxiv.org/abs/2512.09353 + arXiv:2512.09353v1 Announce Type: new +Abstract: Bimetric MOND (BIMOND) is used as a platform for variable-$G$ theories that have MOND-specific idiosyncrasies. E.g., MOND premises dictate return to standard dynamics in the high-acceleration limit, predicting the standard value of $G$ for high-acceleration systems. This automatically ensures compliance of such theories with all the constraints on inconstancy of $G$ that emerge from the study of high-acceleration systems: geophysics, solar system, pulsars, supernovae, stellar evolution, emission of gravitational waves, etc. In MOND, constraints deduced from such phenomena have no bearing on possible $G$ variability in cosmology. My guiding motivation is to see if such theories may account for some roles of dark matter in cosmology; e.g., in accounting for the expansion history of the Universe in the matter-dominated era, by having a $G_e\approx 2\pi G$ govern the later stages of the expansion, instead of invoking matter density $\approx 2\pi\times$ baryon density. Without adding degrees of freedom, or new dimensionful constants, BIMOND can be extended to a class of theories that entail what is best described as phenomenon-dependence of Newton's constant, $G$. I cannot yet present a consistent model that complies with all the observations in cosmology, including the expansion history, with all its details. Instead, I describe some examples of theories in the class that predict different values of $G_e$ in different circumstances, including one where $G$ takes its standard value for all subcosmological systems -- even if they are deep in the MOND regime. I also discuss scenarios in which $G_e\approx G$ in the early Universe, as required by constraints from big-bang nucleosynthesis, but with $G_e> G$ setting in at later times, where it can affect the expansion history during the matter-dominated era. + oai:arXiv.org:2512.09353v1 + astro-ph.CO astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + gr-qc + hep-ph + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.1093/mnras/staf2182 - Yifan Mai, Scott M. Croom, Emily Wisnioski, Andrew J. Battisti, J. Trevor Mendel, Marcie Mun, Caroline Foster, Katherine E. Harborne, Claudia D. P. Lagos, Iris Breda, Tianmu Gao, Kathryn Grasha, Tamal Mukherjee, Adriano Poci, Rhea-Silvia Remus, Piyush Sharda, Sarah M. Sweet, Sabine Thater, Lucas M. Valenzuela, Glenn van de Ven, Tayyaba Zafar, Bodo Ziegler + Mordehai Milgrom - Improvements to the NSO Farside Mapping Pipeline: Noise Reduction Updates - https://arxiv.org/abs/2512.08133 - arXiv:2512.08133v1 Announce Type: new -Abstract: The National Solar Observatory (NSO)'s Farside Pipeline is a critical tool of the space weather industry. It enables the detection and tracking of solar active regions that have rotated to the farside (invisible surface) of the Sun without relying on direct observational platforms such as satellites. By applying the technique of helioseismic holography to continuous Doppler images of the front side (visible surface), the pipeline infers the size and location of these regions through the acoustic signatures. These farside maps, produced using data from the NSO's GONG Network, allow scientists and solar observers to monitor the behavior of solar active regions. They support efforts to protect vital telecommunications and national interest infrastructure. While the data from this pipeline are widely used to many scientific, industrial, and national security applications, global helioseismic monitoring remains a developing field, with ongoing refinements in methodology and reliability. In this report, we will outline the updates made to the NSO's Farside Pipeline which have resulted in more accurate and consistent helioseismic maps, strengthening its value for both operational forecasting and scientific research. - oai:arXiv.org:2512.08133v1 - astro-ph.SR + CWTHF: Subhalo Identification with Continuous Wavelet Transform + https://arxiv.org/abs/2512.09359 + arXiv:2512.09359v1 Announce Type: new +Abstract: With advances in cosmology and computer science, cosmological simulations now resolve structures in increasingly fine detail. As key tracers of hierarchical structure formation, subhalos are among the most important objects within these simulations. In our previous work, we established that the continuous wavelet transform (CWT) can effectively extract clustering information and serve as a robust halo finder. Here, we extend the CWT framework to subhalo identification by adapting the CWTHF (Continuous Wavelet Transform Halo Finder) code. This extension extends the unbinding procedure, which enables the reliable identification of gravitationally bound substructures. The algorithm identifies density peaks within known halos or subhalos and segments the surrounding volume accordingly. Once a new subhalo is registered, its position is recorded to prevent duplicate detection. We validate our approach using the TNG50-2 and TNG100-1 simulations, as well as a single Friends-of-Friends (FOF) halo, by comparing the resulting CWT catalog against the reference SUBFIND catalog. Because the method inherits the original computational framework, our subhalo finder maintains a favorable linear time complexity of $\mathcal{O}(N)$. + oai:arXiv.org:2512.09359v1 astro-ph.IM - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Mitchell Creelman, Kiran Jain, Niles Oien, John Britanik, Thomas M. Wentzel + Minxing Li, Yun Wang, Ping He - Inferring main-sequence stage and buoyancy-glitch amplitudes from Fourier spectra of gravity-mode period spacings: Ensemble Analysis of 26 Slowly Pulsating B Stars - https://arxiv.org/abs/2512.08155 - arXiv:2512.08155v1 Announce Type: new -Abstract: Gravito-inertial-mode asteroseismology of intermediate-mass main-sequence stars took off with the 5-month uninterrupted light curves of the CoRoT space mission. It was developed in detail from the 4-year-long Kepler light curves, which provided a practical means to measure the rotation frequency in the transition layer between the convective core and the radiative envelope, where the local buoyancy frequency reaches a maximum. Recently, a new buoyancy glitch inversion method based on the Fourier spectra of gravity-mode period spacings was developed to probe that region further (Guo 2025). We aim to exploit the information contained in the variability of gravity-mode period spacings ($\Delta P$) in Slowly Pulsating B (SPB) stars with rotation. We investigate how well the main-sequence evolutionary stage can be inferred from this variability. We extract the frequency and amplitude of the variability in $\Delta P$ from the Fourier spectrum (FT). Both the period spacing $\Delta P$ and its periodic perturbations $\delta P$ (deviations from their asymptotic values) are used. The measured dominant frequency of $\Delta P$ allows us to infer the central hydrogen mass fraction, $X_c$, which is a main-sequence age indicator. The inferred $X_c$ values from $FT(\Delta P)$ mostly agree with previous results reported in the literature based on forward modelling of individual identified mode frequencies. - We find that the buoyancy glitches $\delta N/N$ in SPB stars are generally less than $2\%$ in amplitude. Ensemble asteroseismic modeling of gravity-mode pulsators can now be carried out efficiently with our novel $FT(\Delta P)$ method once the internal rotation rate of the pulsators is known. Our methodology offers a fast method for gravito-inertial asteroseismic applications in the era of ongoing and future space-based observations. - oai:arXiv.org:2512.08155v1 - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Exploring Machine Learning Regression Models for Advancing Foreground Mitigation and Global 21cm Signal Parameter Extraction + https://arxiv.org/abs/2512.09361 + arXiv:2512.09361v1 Announce Type: new +Abstract: Extracting parameters from the global 21cm signal is crucial for understanding the early Universe. However, detecting the 21cm signal is challenging due to the brighter foreground and associated observational difficulties. In this study, we evaluate the performance of various machine-learning regression models to improve parameter extraction and foreground removal. This evaluation is essential for selecting the most suitable machine learning regression model based on computational efficiency and predictive accuracy. We compare four models: Random Forest Regressor (RFR), Gaussian Process Regressor (GPR), Support Vector Regressor (SVR), and Artificial Neural Networks (ANN). The comparison is based on metrics such as the root mean square error (RMSE) and $R^2$ scores. We examine their effectiveness across different dataset sizes and conditions, including scenarios with foreground contamination. Our results indicate that ANN consistently outperforms the other models, achieving the lowest RMSE and the highest $R^2$ scores across multiple cases. While GPR also performs well, it is computationally intensive, requiring significant RAM and longer execution times. SVR struggles with large datasets due to its high computational costs, and RFR demonstrates the weakest accuracy among the models tested. We also found that employing Principal Component Analysis (PCA) as a preprocessing step significantly enhances model performance, especially in the presence of foregrounds. + oai:arXiv.org:2512.09361v1 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhao Guo, Conny Aerts + Anshuman Tripathi, Abhirup Datta, Gursharanjit Kaur - Estimation of the Hubble parameter from unedited compact object merger catalogues - https://arxiv.org/abs/2512.08164 - arXiv:2512.08164v1 Announce Type: new -Abstract: In recent years, constraints on the Hubble parameter using multiple dark sirens have been made,relying on a galaxy catalogue, correlations between the mass and redshift distributions, or both. Those studies have typically used only significant gravitational wave candidates. In this work, we present a framework for cosmological inference that bypasses per-candidate parameter estimation, uses only detection-level information. This allows the population inference from a candidate list produced directly by a search pipeline, without additional selection cuts. Our method is particularly suited to extracting information from marginal candidates, which are essential for probing the distant universe. - oai:arXiv.org:2512.08164v1 - astro-ph.CO - astro-ph.IM - gr-qc - Wed, 10 Dec 2025 00:00:00 -0500 + Constraining the outer boundary condition for the Babcock-Leighton dynamo models + https://arxiv.org/abs/2512.09371 + arXiv:2512.09371v1 Announce Type: new +Abstract: The evolution of the Sun's large-scale surface magnetic field is well captured by surface flux transport models, which can therefore provide a natural constraint on the outer boundary condition (BC) of Babcock-Leighton (BL) dynamo models. For the first time, we propose a zero radial diffusion BC for BL dynamo models, enabling their surface field evolution to align consistently with surface flux transport simulations. We derive a zero radial diffusion BC from the Magnetohydrodynamic induction equation and evaluate its effects in comparison with two alternatives: (i) a radial outer BC, and (ii) a radial outer BC combined with strong near-surface radial pumping. The comparison is carried out both for the evolution of a single bipolar magnetic region and within a full BL dynamo model. The zero radial diffusion outer BC effectively suppresses radial diffusion across the surface, ensuring consistency between the evolution of the bipolar magnetic region in the BL dynamo and the surface flux transport model. With this outer BC, the full BL dynamo model successfully reproduces the fundamental properties of the solar cycle. In addition, the model naturally produces a surface magnetic field that is not purely radial, in closer agreement with solar observations. The physically motivated zero radial diffusion boundary condition paves the way for deeper insight into the solar and stellar cycles. + oai:arXiv.org:2512.09371v1 + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Reiko Harada, Heather Fong, Kipp Cannon + Yukun Luo, Jie Jiang, Binghang Li, Zebin Zhang, Ruihui Wang - NEOWISE data and Thermophysical Modeling of 98943 Torifune (2001 CC21) - https://arxiv.org/abs/2512.08181 - arXiv:2512.08181v1 Announce Type: new -Abstract: The Hayabusa2# flyby target 98943 Torifune (2001 CC21) has an uncertain size based on an uncertain albedo and uncertain absolute magnitude. We have collected all the NEOWISE observations of 2001 CC21 from Nov 2021 through Feb 2024, a total of 132 frames, and analyzed this data to estimate an infrared radiometric diameter. We analyze the multi-epoch 3.4 and 4.6 micron NEOWISE data using an ellipsoidal rotating, cratered ThermoPhysical Model (TPM) to obtain estimates for the diameter, rotation pole, shape, and thermal inertia. 2001 CC21 is quite faint at 4.6 microns when Delta is about 0.7 AU, so the resulting diameter is substantially smaller than the 700 meters derived from the H magnitude and L spectral type. Recent polarimetric data has also suggested a smaller diameter, but not quite as small as the diameter derived from the thermal IR data. A fit to an ellipsoidal TPM model gives a volume equivalent sphere diameter of 337-27+33 meters [posterior median and central 68% confidence interval]. Prograde rotation with an obliquity of 24-9+6 deg is preferred. We also applied this TPM to the Spitzer data presented by Fornasier etal. (2024) and obtain a diameter of 476 +/- 9% meters which is consistent with the NEATM modeling presented by Fornasier etal. but with more realistic errorbars. Finally, fitting the NEOWISE and Spitzer data together requires unexpectedly large thermal inertias and gives a bimodal posterior diameter distribution. - oai:arXiv.org:2512.08181v1 - astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + SN 2022ngb: a faint, slow-evolving Type IIb Supernova with a low-mass envelope + https://arxiv.org/abs/2512.09384 + arXiv:2512.09384v1 Announce Type: new +Abstract: An extensive photometric and spectroscopic follow-up campaign of the Type IIb SN 2022ngb is presented in the article. Through detailed modeling of this dataset, we aim to constrain the key physical parameters of the explosion, infer the nature of the progenitor star and its environment, and probe the dynamical properties of the ejecta. We analyze photometric and spectroscopic data of SN 2022ngb. By constructing and modeling the bolometric light curve with semi-analytic models, we estimate the primary explosion parameters. The spectroscopic data are compared with those of well-studied SNe IIb and NLTE models to constrain the properties of the progenitor and the structure of the resulting ejecta. SN 2022ngb is a low-luminosity SN IIb with a peak bolometric luminosity of L_bol = 7.76 (+1.15/-1.00) x 10^41 erg/s and a V-band rising time of 24.32 +/- 0.50 days. Light curve modeling indicates an ejecta mass of ~2.9-3.2 M_sun, an explosion energy of ~1.4 x 10^51 erg, and a low synthesized 56Ni mass of ~0.045 M_sun. Nebular phase spectra exhibit asymmetric line profiles, pointing to a non-spherical explosion and an anisotropic distribution of radioactive material. Our analysis reveals a relatively compact stripped-envelope progenitor with a pre-SN mass of approximately 4.7 M_sun (corresponding to a 15-16 M_sun ZAMS star). Our analysis suggests that SN 2022ngb originated from the explosion of a moderate-mass relatively compact, stripped-envelope star in a binary system. The asymmetries inferred from the nebular phase spectral line features suggest a non-spherical explosion. + oai:arXiv.org:2512.09384v1 + astro-ph.SR + astro-ph.GA + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Edward L. (Ned), Wright (UCLA), Jospeh Masiero (IPAC), Amy Mainzer (UCLA) + J. -W. Zhao, S. Benetti, Y. -Z. Cai, A. Pastorello, N. Elias-Rosa, A. Reguitti, G. Valerin, Z. -Y. Wang, E. Cappellaro, G. -F. Feng, A. Fiore, B. Fitzpatrick, M. Fraser, J. Isern, E. Kankare, T. Kravtsov, B. Kumar, P. Lundqvist, K. Matilainen, S. Mattila, P. A. Mazzali, S. Moran, P. Ochner, Z. -H. Peng, T. M. Reynolds, I. Salmaso, S. Srivastav, M. D. Stritzinger, S. Taubenberger, L. Tomasella, J. Vink\'o, J. C. Wheeler, S. Williams, S. -P. Pei, Y. -J. Yang, X. -K. Liu, X. -W. Liu, Y. -P. Yang - Follow-up Observations of Candidate White Dwarf Planets with MIRI - https://arxiv.org/abs/2512.08191 - arXiv:2512.08191v1 Announce Type: new -Abstract: We report on second-epoch imaging of two candidate planet-hosting white dwarfs stars, WD2105-82 and WD1202-232. Both stars showed evidence of resolved, planet-mass candidate companions in observations using the MIRI mid-infrared imager on JWST. WD2105-82 also showed evidence of an infrared excess consistent with an unresolved 1.4 Jupiter mass companion with an orbital separation of <4 au. Our second epoch observations confirm that the source of the excess shares common proper motion with the star. The excess is almost certainly due to a companion planet or debris disk. However, neither of the two resolved sources with projected separations of >1" in the first epoch of JWST observations show measurable proper motion and are thus likely faint, unresolved background galaxies. We also search for common proper motion companions out to hundreds of au, but find no evidence of widely separated companions. - oai:arXiv.org:2512.08191v1 + The Statistical Analysis Of The Galactic Open Clusters' Structure + https://arxiv.org/abs/2512.09387 + arXiv:2512.09387v1 Announce Type: new +Abstract: We present a systematic investigation of 1,481 Galactic open clusters (OCs) through the application of the Limepy dynamical model, from which we derive the fundamental structural parameters of OCs. We conduct the statistical analyses on the structural parameters with clusters' ages and locations within the Milky Way. Our results reveal the higher concentration in the cluster centeris associated with the sharper truncation at the periphery of cluster, which is consistent with previous findings for globular clusters(GCs). We further find the systematic increase of the lower limit of clusters' half-mass radius (Rh) with age. Our results also show that OCs located at larger vertical distances from the Galactic plane systematically display higher central concentrations. Our findings collectively suggest that the structural characteristics of OCs are shaped by both intrinsic evolutionary processes and interactions with the Galactic environment. During the evolution of star clusters, the combined effects of mass segregation and tidal stripping lead to the systematic pattern between central concentration and outer truncation. Clusters of different ages and locations within the Milky Way undergo different evolutionary histories, resulting in correlations between the Rh and age, as well as between central concentration and galactic location. + oai:arXiv.org:2512.09387v1 + astro-ph.GA astro-ph.SR - astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Fergal Mullally, Susan E. Mullally, Misty Cracraft, Samantha N. Bianco, Loic Albert, John Debes, J. J. Hermes, Mukremin Kilic, William T. Reach + Jin-Sheng Qiu, Zhen Wan, Xu-Zhi Li, Qing-Feng Zhu, Lu-lu Fan, Xiao-Hui Xu, Jun-Han Zhao, Zhi-Yong Pu - Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. XV. Reverberation Mapping of Mg II Emission Lines - https://arxiv.org/abs/2512.08192 - arXiv:2512.08192v1 Announce Type: new -Abstract: As the 15th paper in a series reporting on a large reverberation mapping (RM) campaign of super-Eddington accreting massive black holes (SEAMBHs) in active galactic nuclei (AGNs), we present the results of measurements of the Mg II lines in 18 SEAMBHs monitored spectroscopically from 2017 to 2024. Among these, the time lags of Mg II have been successfully determined for 8 of the 18 objects, thereby expanding the current Mg II RM sample, particularly at higher accretion rates. By incorporating measurements of the line widths, we determine the masses of their central supermassive black holes. Based on these new measurements, we update the relation between the Mg II radius and the monochromatic luminosity at 3000 $\mathring{\mathrm{A}}$ ($R_{\rm MgII}-L_{3000}$ relation), yielding a slope of $0.24 \pm 0.03$, which is slightly shallower than, yet still consistent with, previously reported values. Similar to the H$\beta$ lines, the Mg II time lags in SEAMBHs are shorter than those of AGNs with normal accretion rates at comparable luminosities. The deviation of AGNs from the best-fit $R_{\rm MgII}-L_{3000}$ relation shows a strong correlation with the accretion rate, while no significant correlation is found between the deviation and the flux ratio of UV iron to Mg II. - oai:arXiv.org:2512.08192v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Confirming the Magnetic Field Detection at the Surface of $\chi$ Cyg + https://arxiv.org/abs/2512.09392 + arXiv:2512.09392v1 Announce Type: new +Abstract: We present spectropolarimetric observations of $\chi$ Cygni obtained with Neo-Narval at T\'elescope Bernard Lyot in 2025. We obtained observations across three epochs (2025 Jul, Aug, and Oct) near maximum light to search for magnetic field signatures at the stellar photosphere. We detected a clear circular polarization signal in the 2025 Aug observations (pulsation phases $0.99$ to $0.01$). We measure a mean longitudinal magnetic field of $B_l = 3.4 \pm 0.6$ G. No detections were obtained for the 2025 Jul and Oct epochs. The pulsation-phase dependence suggests that field detection is tied to specific shock conditions near maximum light. + oai:arXiv.org:2512.09392v1 + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Hua-Rui Bai (SEAMBH collaboration), Pu Du (SEAMBH collaboration), Chen Hu (SEAMBH collaboration), Yong-Jie Chen (SEAMBH collaboration), Zhu-Heng Yao (SEAMBH collaboration), Yan-Rong Li (SEAMBH collaboration), Yi-Xin Fu (SEAMBH collaboration), Yi-Lin Wang (SEAMBH collaboration), Yu Zhao (SEAMBH collaboration), Hao Zhang (SEAMBH collaboration), Jun-Rong Liu (SEAMBH collaboration), Sen Yang (SEAMBH collaboration), Yue-Chang Peng (SEAMBH collaboration), Feng-Na Fang (SEAMBH collaboration), Yu-Yang Songsheng (SEAMBH collaboration), Ming Xiao (SEAMBH collaboration), Shuo Zhai (SEAMBH collaboration), Sha-Sha Li (SEAMBH collaboration), Kai-Xing Lu (SEAMBH collaboration), Zhi-Xiang Zhang (SEAMBH collaboration), Dong-Wei Bao (SEAMBH collaboration), Wei-Jian Guo (SEAMBH collaboration), Jia-Qi Feng (SEAMBH collaboration), Yi-Peng Zhao (SEAMBH collaboration), Jes\'us Aceituno (SEAMBH collaboration), Jin-Ming Bai (SEAMBH collaboration), Luis C. Ho (SEAMBH collaboration), Jian-Min Wang (SEAMBH collaboration) + http://creativecommons.org/licenses/by/4.0/ + 10.3847/2515-5172/ae290e + Res. Notes AAS 9 327, 2025 + Alexis Lavail, Arturo L\'opez Ariste, Quentin Pilate, Philippe Mathias, Fabrice Herpin, Agn\`es L\`ebre - First detection of X-ray polarization from the long-period X-ray pulsar 4U 1954+319 - https://arxiv.org/abs/2512.08195 - arXiv:2512.08195v1 Announce Type: new -Abstract: We report the first detection of X-ray polarization with the Imaging X-ray Polarimetry Explorer (IXPE) from the X-ray pulsar (XRP) 4U 1954+319. The source belongs to an extremely rare class of systems in which a slowly rotating neutron star accretes from the dense wind of a red supergiant companion. Coherent pulsations are detected at $P_{\rm spin}=5.49\pm0.05$ h, which is one of the longest spin periods known among XRPs. While the phase-averaged analysis shows no significant polarization, with a 99% confidence minimum detectable polarization (MDP$_{99}$) of 5.0% in the 2-8 keV band, the phase-resolved analysis shows one interval at pulse maximum in which the polarization degree (PD) exceeds its MDP$_{99}$, giving ${\rm PD}=10.3\pm3.1$%. The polarization angle (PA) exhibits a smooth $\approx140^{\circ}$ rotation over the pulse, and a joint evaluation of all phase bins yields an overall detection significance of $3.3\sigma$. Using the rotating vector model, we identify the geometric solution that reproduces the observed PA variation. By subsequently applying an event-by-event derotation of the Stokes parameters based on this solution, we remove the PA swing and recover the phase-averaged polarization which is detected at the $5.2\sigma$ level. - oai:arXiv.org:2512.08195v1 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Probing stellar rotation in the Pleiades with gravity-mode pulsators + https://arxiv.org/abs/2512.09395 + arXiv:2512.09395v1 Announce Type: new +Abstract: Due to their proximity, the Pleiades are an important benchmark open cluster. Despite its status, asteroseismic analyses of its members are rare. In particular, the gravity-mode (g-mode) pulsators, which allow inference of stellar near-core properties have not been analysed yet. We aim to identify and analyse the population of g-mode pulsators in the Pleiades. Our focus lies on the internal rotation as measured from asteroseismology to obtain a well defined sample of stellar rotation on the early main sequence. Based on full-frame images from the Transiting Exoplanet Survey Satellite (TESS), we constructed light curves for intermediate-mass Pleiades members and searched for g-mode pulsators among them. For pulsators exhibiting period spacing patterns, we determined their near-core rotation rate and buoyancy periods. For all other g-mode pulsators, we estimated the near-core rotation rate based on the dominant mode frequency to obtain a comprehensive rotation rate distribution. Among our 105 target stars, we find 28 g-mode pulsators distributed across the entire upper main sequence, 19 of which are hybrid pulsators, but only three stars exhibit period spacing patterns in the current TESS data. The near-core rotation rates in A- and early F-type members are distributed between 1 and 3 d$^{-1}$ without any clear mass-dependence. This distribution is much broader than the one in the similar open cluster NGC 2516. A comparison of the buoyancy periods shows that the Pleiades and NGC 2516 are of similar asteroseismic age. With the large population of g-mode and hybrid pulsators, the Pleiades constitute a valuable asteroseismic benchmark cluster, reaffirming its important role in stellar astrophysics. + oai:arXiv.org:2512.09395v1 + astro-ph.SR + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Alexander Salganik, Lingda Kong, Sofia V. Forsblom, Menglei Zhou, Honghui Liu, Sergey S. Tsygankov, Andrea Santangelo, Juri Poutanen + http://creativecommons.org/licenses/by/4.0/ + D. J. Fritzewski, A. Kemp, G. Li, C. Aerts - Supernovae Shock Breakout from Red Supergiants in Two Dimensions - https://arxiv.org/abs/2512.08212 - arXiv:2512.08212v1 Announce Type: new -Abstract: We present new two-dimensional radiation hydrodynamic simulations of supernova shock breakout from red supergiants using the $\texttt{CASTRO}$ code. Our progenitors are 20 and 25 M$_{\odot}$ solar-metallicity stars evolved from the zero-age main sequence with $\texttt{MESA}$ and exploded in one dimension using $\texttt{FLASH}$. We consider a range of circumstellar media (CSM) produced by stellar winds to investigate how pre-explosion mass-loss affects shock breakout. The multigroup flux-limited diffusion scheme in $\texttt{CASTRO}$ captures the interaction between the explosion shock, its radiation precursor, and the surrounding CSM. We find that strong radiation precursors, generated by radiation leakage behind the shock, can drive fluid instabilities and move the effective photosphere outward before the shock reaches the stellar surface. The resulting breakout emissions reach peak luminosities of ${\sim}10^{44}$ erg s$^{-1}$ with full-width half-maximum durations of 1-3 hr, which are much dimmer and longer than those from blue supergiants. The light-curve colors gradually evolve from blue to red after the peak. The 25 M$_{\odot}$ model with explosion energy $E \sim 1.69\times10^{51}$ erg produces ${\sim}$10-30\% higher maximum luminosity than the 20 M$_{\odot}$ model with $E \sim 1.09\times10^{51}$ erg. The dense CSM further extends the breakout rise time by increasing the photon diffusion. These results provide new constraints on red supergiant atmospheres and mass-loss histories prior to core collapse. - oai:arXiv.org:2512.08212v1 + X-ray Polarization and Spectral Variations in an Extreme High-Synchrotron-Peaked Blazar 1ES 1101--232 + https://arxiv.org/abs/2512.09448 + arXiv:2512.09448v1 Announce Type: new +Abstract: We present the first X-ray polarimetric observation of the extreme high-synchrotron-peaked blazar 1ES 1101--232, conducted by the Imaging X-ray Polarimetry Explorer (IXPE). The data analysis incorporates simultaneous and quasi-simultaneous observations from Swift-XRT and NuSTAR. Our results reveal a significant detection of X-ray polarization in the 2--6 keV band at a confidence level (CL) of 6.6$\sigma$, with a polarization degree of $\Pi_{\rm X}=17.9\%\pm2.7\%$ and an electric vector position angle (EVPA) of $\psi_{\rm X}=10^\circ.0\pm4^\circ.4$. An even higher polarization degree of $\Pi_{\rm X}=38.9\%\pm9.1\%$ with an EVPA of $\psi_{\rm X}=13^\circ.9\pm6^\circ.7$ is observed within a narrower time interval, at a CL of 4.3$\sigma$. During the IXPE observational campaign, the X-ray spectrum of 1ES 1101--232 exhibits a clear soft-to-hard spectral evolution in the 0.3--10 keV band, although no significant flux variability is detected. Additionally, a clockwise hysteresis loop is identified in the flux--photon index plane. These findings collectively indicate that the X-ray emission from 1ES 1101--232 originates in a region characterized by a well-ordered magnetic field through synchrotron radiation. + oai:arXiv.org:2512.09448v1 astro-ph.HE - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Wun-Yi Chen, Ke-Jung Chen, Keiichi Maeda, Masaomi Ono, Po-Sheng Ou, F. K. Roepke + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Xin-Ke Hu, Jin Zhang, Fei Xie, Xiang-Gao Wang - The Birth of Be Star Disks II. A High-Resolution Spectroscopic Campaign and TESS Observations of an Outburst of the Classical Be star {\lambda} Pavonis - https://arxiv.org/abs/2512.08214 - arXiv:2512.08214v1 Announce Type: new -Abstract: Be stars are non-supergiant, rapidly rotating B stars that have shown emission lines originating in a circumstellar disk. The exact mechanisms that lead to disk formation and dissipation are not fully known although progress has been made with some systems. Here, we present a study of a disk outburst of the southern Be star {\lambda} Pavonis (HD 173948). Our dataset comprises 698 high-resolution spectra taken contemporaneously with TESS photometry in 2023. During the final days of TESS monitoring, the star began building a disk from a pristine diskless state. We find that the disk built within 5 days in optical H I and He I lines, while the disk is circularized in about 12 days. The disk began to decay in higher energy He I first, then lower energy transitions, with the decay ending last for H{\alpha}. We examine non-radial pulsations both through TESS photometry and the line profile variations in Balmer lines, He I lines, and the weak photospheric Si III 5739 line. Our analysis indicates that two periodicities seen in TESS photometry (at 1.644 and 1.485 cycles/d) are not seen in the spectral lines before, during, or after the outburst. The strongest spectral signal is a periodicity at 0.163 cycles/d, which appears as a difference between the weaker signals. We additionally find evidence for fast non-photometric pulsational variations over the course of spectroscopy obtained before, during, and after the outburst. These fast LPVs are strong, and interfere with the two weaker signals, causing their apparent incoherence. - oai:arXiv.org:2512.08214v1 - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Constraints on Spatial Curvature and Dark Energy Dynamics in the $w$CDM Model from DESI DR1 and DR2 + https://arxiv.org/abs/2512.09486 + arXiv:2512.09486v1 Announce Type: new +Abstract: In this study, we investigate the $w$CDM dynamical dark energy model with spatial curvature utilizing the recently released DESI Collaboration data (DR1 and DR2) in conjunction with other observational probes such as BBN, Observational Hubble Data (OHD), and Pantheon Plus (PP). Our investigation attempts to discover which DESI dataset gives a better match to the $w$CDM framework and assess the impact of spatial curvature on cosmological constraints. We find that the cosmic curvature parameter, $\Omega_k$, disfavors the cosmological constant for the DR2+BBN and DR2+BBN+OHD data combinations. However, the deviation from the cosmological constant remains below the $1\sigma$ level, indicating a mild preference for a open universe. In contrast, when using the DR1 based combinations namely DR1+BBN and DR1+BBN+OHD-the deviation from the cosmological constant increases to approximately $1.2\sigma$, suggesting a slightly stronger indication of a open geometry. Also, the best-fit values of the Hubble constant ($H_0$) obtained from the DR1+BBN+OHD+PP and DR2+BBN+OHD+PP combinations within the dynamical dark energy model are consistent with the results reported by the Planck Collaboration. Our findings provide constraints on the dark energy EoS parameter $ w_{\mathrm{}0}$, reveal a mild but notable deviation from the vacuum energy ($w = -1$) scenario at a significance level $1.8\sigma$ from DR2+BBN+OHD+PP and $0.5\sigma$ from DR1+BBN+OHD+PP, both favoring the quintessence region of dark energy. Furthermore, the key physical distance measures $D_H$, $D_V$, and $D_M$ show better consistency with our model when analyzed with the DR2 data. + oai:arXiv.org:2512.09486v1 + astro-ph.CO + gr-qc + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Sola S. Nova, Noel D. Richardson, Jonathan Labadie-Bartz, Samantha Garcia Flores + http://creativecommons.org/publicdomain/zero/1.0/ + 10.1016/j.jheap.2025.100514 + Journal of High Energy Astrophysics, Vol. 50, Issue February, (2026), Article No. 100514 (11 pages) + Manish Yadav, Archana Dixit, M. S. Barak, Anirudh Pradhan - The Head-on Collision of a Neutron Star with a White Dwarf - https://arxiv.org/abs/2512.08231 - arXiv:2512.08231v1 Announce Type: new -Abstract: We have computed the physical processes involved in a head-on collision between a neutron star (NS) and a white dwarf (WD). The outcomes of such collisions vary depending on the mass and type of the WD. We have separately examined the dynamical processes for collisions between NSs and helium WDs (He-WDs), carbon-oxygen WDs (CO-WDs), and oxygen-neon WDs (ONe-WDs). We aim to investigate whether the collision can trigger a thermonuclear explosion of the WD, and if not, whether the NS can remain bound within the WD to form a Thorne-Zytkow-like object (TZlO). For a thermonuclear explosion to occur, at least two conditions must be satisfied: (i) the collision-induced temperature must reach the ignition threshold of the relevant nuclear reactions, and (ii) the burning material must remain in a degenerate state. For different types of WDs, there exist parameter ranges where both conditions are fulfilled, implying that NS-WD collisions can indeed induce thermonuclear explosions, leading to sub-Chandrasekhar Type Ia supernovae or other exotic optical transients powered by thermonuclear explosion. On the other hand, the formation of a TZlO requires that the WD material exerts sufficient drag on the NS to prevent its escape, while the interaction must not trigger a thermonuclear explosion of the WD. Our results indicate that such conditions can be realized in the case of low-mass CO-WDs and low-mass ONe-WDs, provided that the viscous coefficient is sufficiently large. - oai:arXiv.org:2512.08231v1 + Dirac vs. Majorana Dark Matter Imprints on Neutron Star Observables + https://arxiv.org/abs/2512.09498 + arXiv:2512.09498v1 Announce Type: new +Abstract: The fundamental character of a fermionic dark matter, whether it is a Dirac or Majorana particle remains a key unresolved issue whose answer would profoundly affect dark-sector phenomenology and detection strategies thereby motivates complementary probes across particle and astrophysical experiments. Compact stars, particularly neutron stars, offer unique astrophysical laboratories for probing such fundamental properties under extreme densities. The presence of a fermionic DM admixed with nuclear matter can modify the equation of state, thereby affecting observable quantities such as the mass-radius (M-R) relation and tidal deformability. In this work, we investigate how the intrinsic particle nature of fermionic DM influences neutron star structure. Within a relativistic mean-field framework extended by a scalar (or Higgs like) portal coupling between DM and nucleons, we construct self-consistent equation of states for both Dirac and Majorana cases and solve the Tolman-Oppenheimer-Volkoff equations to obtain stellar configurations. Owing to the difference in internal degrees of freedom, Dirac DM (four degrees of freedom) generally softens the equation of state more strongly than Majorana DM (two degrees of freedom), leading to smaller radii and lower maximum masses. We identify the parameter space consistent with current NICER and gravitational-wave constraints, highlighting the potential of compact-star observations to discriminate between Dirac and Majorana dark matter. + oai:arXiv.org:2512.09498v1 astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + hep-ph + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.3847/1538-4357/ae1583 - Zong-kai Peng, He Gao, Xian-Fei Zhang + M. Bhuyan (IOP BBSR), Jeet Amrit Pattnaik (IOP BBSR), S. K. Patra (SOA Univ.), Sudhanwa Patra (IIT Bhilai,IOP BBSR) - The Impact of Irradiation on the Radius and Thermal Evolution of Transiting Brown Dwarfs - https://arxiv.org/abs/2512.08249 - arXiv:2512.08249v1 Announce Type: new -Abstract: Masses and radii of transiting brown dwarfs can be measured directly in contrast to isolated field brown dwarfs, whose mass and radius inferences are model dependent. Therefore, transiting brown dwarfs are a testbed for the interior and evolutionary models of brown dwarfs and giant exoplanets. We have developed atmospheric and evolutionary models for this emerging population. We show that intense stellar irradiation can cause a large enhancement in the radius of transiting brown dwarfs at all masses, especially if the incident flux exceeds $log_{10}(F/cgs)\ge$9 ($T_{\rm eq}\ge 1450$ K). Stellar irradiation can significantly alter rates of nuclear burning in irradiated brown dwarfs, making the Deuterium-burning and Hydrogen-burning minimum masses strong functions of incident stellar flux. We show that the D-burning and H-burning minimum masses can decrease by 16% and 13%, respectively, between isolated and strongly irradiated brown dwarfs ( $log_{10}(F/cgs)\ge$10 ($T_{\rm eq}\ge 2570$ K)). This shows that stellar irradiation has a larger impact on the planet-brown dwarf-star mass boundaries than metallicity or clouds. We show that metal cores or migration affect their evolution to a much lesser extent, whereas low mass highly irradiated old sources can help us test the physics of hot Jupiter radius anomaly. We fit the observed radii of 46 transiting brown dwarfs and show that our irradiated evolutionary models fit their radii better than models that ignore the host star, especially for highly irradiated objects. However, the measured radii of 10 objects are still inconsistent at $>3\sigma$ level, indicating residual gaps in our irradiated evolutionary model. - oai:arXiv.org:2512.08249v1 - astro-ph.EP - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + SLICE -- Combining Strong Lensing and X-ray in AC\,114. Insights into the Merger Scenario + https://arxiv.org/abs/2512.09512 + arXiv:2512.09512v1 Announce Type: new +Abstract: AC114 is a historically significant galaxy cluster, being one of the first strong lensing clusters detected from the ground in the early 1990s, prior to the launch of the HST. Despite this early prominence, no detailed lensing analyses have been carried out for more than fifteen years. We here study this cluster using JWST imaging obtained as part of the SLICE program, complemented by archival HST and X-ray observations. JWST data reveal ten new multiply imaged systems and enable the identification of conjugate substructures in several of the sixteen systems, significantly increasing the number of strong lensing constraints. Using these data, we construct a parametric mass model with Lenstool and extend it by explicitly incorporating the Chandra data in a combined strong lensing+X-ray fit. Our best-fit model reproduces the multiple images with an RMS of 0.4" while simultaneously matching the X-ray data. The dark matter distribution is unimodal and centered on the brightest cluster galaxy, with a large core radius of 83+-5kpc, consistent with values reported in other strong lensing clusters. The strong lensing constraints require the inclusion of an external shear component which position angle points unambiguously towards a nearby (~1Mpc), well defined mass concentration at the same redshift in the North-West, for which we propose the naming AC114b. The spatial coverage of the XMM-Newton data encompasses the whole structure, allowing us to probe the X-ray properties of the companion cluster and the thermodynamics of AC114, providing evidence for a major merger, in line with previous signatures seen in Chandra, radio and optical spectroscopic data. Our results shed new light on the merging scenario, revealing a major merger caught in a late post-collisional phase, where AC114 is the dominant system and Ac114b has likely been stripped of its hot gas. + oai:arXiv.org:2512.09512v1 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Sagnick Mukherjee, Jonathan J. Fortney, Theron W. Carmichael, C. Evan Davis, Daniel P. Thorngren + Marceau Limousin, Benjamin Beauchesne, Keren Sharon, Johan Richard, Gourav Khullar, Mathilde Jauzac, Mike Gladders, Eric Jullo, Catherine Cerny, Stefano Ettori, Gavin Leroy, Nency Patel - The Milky Way Imaging Scroll Painting Survey: Data Release 1 - https://arxiv.org/abs/2512.08260 - arXiv:2512.08260v1 Announce Type: new -Abstract: We present the first data release (DR1) of the Milky Way Imaging Scroll Painting (MWISP) survey, a mapping in the J=(1-0) transition lines of 12CO, 13CO, and C18O toward the northern Galactic plane during 2011-2022. The MWISP survey was conducted using the PMO 13.7 m telescope at a spatial resolution of approximately 50" and a velocity resolution of 0.16 km/s at 115 GHz. DR1 fully covered 2310 square degrees within the Galactic longitude (l) and latitude (b) range of 9.75 deg =< l=< 229.75 deg and |b| =< 5.25 deg. The surveyed area was divided into cell units of 30'x30' for practical purposes and On-The-Fly (OTF) mapping was performed toward each target cell unit. The data were regridded into a regular 3D datacube in l-b-V_LSR with a pixel size of 30" in l-b axes and 0.16 km/s in theV_LSR axis. The median rms noise is 0.47 K, 0.25 K, and 0.25 K for 12CO, 13CO, and C18O, respectively. The equivalent 3 sigma sensitivity in 12CO luminosity is approximately 0.23 K km/s, making MWISP the most sensitive survey of its kind. In this paper, we describe the survey data, including the calibration, data cleaning, data mosaic processes, and the data products. The final mosaicked data cubes contain about 3.33x10^7 spectra (pixels) for each CO isotopologue line. Color composite images, made from the intensities of the isotopologue lines, and some concise descriptions are provided. We constructed a molecular cloud catalog based on the mosaicked 12CO data cube using the clustering algorithm DBSCAN, detecting 103,517 molecular clouds, 10,790 of which exhibit 13CO emission and 304 of which show C18O emission. Based on the histogram of voxel brightness temperature, we estimated a total 12CO flux of 7.69+/-0.38x10^7 K km/s arcmin^2, 82% of which is captured by the DBSCAN algorithm. The data, together with the cloud sample, provide unique information on molecular gas in the northern Milky Way. - oai:arXiv.org:2512.08260v1 + CASCADE: Filamentary accretion flows in Cygnus X DR20 + https://arxiv.org/abs/2512.09519 + arXiv:2512.09519v1 Announce Type: new +Abstract: Aims. We investigate the role of filaments in high-mass star formation, whether gas flows from large to small scales along them, and what their properties might reveal about the region they are found in. Methods. The Max Planck IRAM Observatory Program (MIOP), the Cygnus Allscale Survey of Chemistry and Dynamical Environments (CASCADE), includes high spatial resolution (~3'') data of HCO+(1-0) and H13CO+(1-0) emission in the star-forming DR20 region in the Cygnus X complex. In this data we identify filaments with the structure identification algorithm DisPerSE. We further analyze these filaments using Gaussian fits to the spectra to determine the line peak velocity and full width half maximum along them. The Python package FilChaP was used to determine filament widths. Results. We find projected velocity gradients inside several filaments between 0.4 to 2.4km/s over projected length-scales of 0.1pc toward star-forming cores. This can be interpreted as a sign of gas flowing along the filaments toward the cores. The filament width distributions exhibit median values between 0.06 and 0.14pc depending on the core, the tracer, and the method. Standard deviations are approximately 0.02 to 0.06pc. These values are roughly in agreement with the filament width of 0.1pc typically found in nearby low-mass star-forming regions. Conclusions. This first analysis of filamentary properties within the Cygnus X CASCADE program reveals potential signatures of gas flows along filaments onto star-forming cores. Furthermore, the characteristics of the filaments in this high-mass star-forming region can be compared to those of filaments in low-mass star-forming regions typically studied before. Extending such studies to the entire CASCADE survey will enhance our knowledge of high-mass filament properties on solid statistical grounds. + oai:arXiv.org:2512.09519v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Ji Yang (Qinghai), Qing-Zeng Yan (Qinghai), Yang Su (Qinghai), Shaobo Zhang (Qinghai), Xin Zhou (Qinghai), Yan Sun (Qinghai), Yiping Ao (Qinghai), Xuepeng Chen (Qinghai), Zhiwei Chen (Qinghai), Fujun Du (Qinghai), Min Fang (Qinghai), Yan Gong (Qinghai), Zhibo Jiang (Qinghai), Shengyu Jin (Qinghai), Chong Li (Qinghai), Yingjie Li (Qinghai), Yi Liu (Qinghai), Dengrong Lu (Qinghai), Chunsheng Luo (Qinghai), Yuehui Ma (Qinghai), Ruiqing Mao (Qinghai), Jixian Sun (Qinghai), Chen Wang (Qinghai), Hongchi Wang (Qinghai), Min Wang (Qinghai), Min Wang (Qinghai), Xindong Wang, Wenting Xu, Ye Xu, Kun Yan, Ping Yan, Lixia Yuan, Miaomiao Zhang, Yongxing Zhang - - - Isocurvature Induced Gravitational Waves at Pulsar Timing Arrays - https://arxiv.org/abs/2512.08301 - arXiv:2512.08301v1 Announce Type: new -Abstract: Gravitational waves (GWs) are powerful probes of new physics in the early Universe. In particular, GWs induced by primordial isocurvature perturbations encode information of novel dynamics beyond the standard $\Lambda$CDM model. Existing studies of isocurvature induced GWs focus on a particular type: cold dark matter (CDM) isocurvature. In this work, we present a more comprehensive study of four kinds of isocurvature involving CDM, baryons, neutrinos and free-streaming dark radiation (DR). We first reformulate initial conditions of isocurvature with coupled neutrinos because modes relevant for observations at Pulsar Timing Arrays enter the horizon before neutrino decoupling. With these new initial conditions, neutrino isocurvature is phenomenologically similar to CDM isocurvature up to an overall coefficient, which leads to an interesting conversion of isocurvature between radiation and matter sectors. We then find that the spectrum of isocurvature induced GWs from free-streaming DR is qualitatively different than that from CDM due to the presence of anisotropic stress. Unlike GWs induced by CDM isocurvature that are suppressed at high frequencies due to matter density being suppressed at early times, DR isocurvature induced GWs is proportional to the constant ratio between DR density and total radiation. Finally, we utilize two general parametrizations of the isocurvature power spectrum: a delta function and a broken power law, and derive novel constraints with recent NANOGrav data. Our results set stringent constraints on isocurvature around $10^{6}\,\textrm{Mpc}^{-1}$, which are complementary to cosmological observations at large scales. - oai:arXiv.org:2512.08301v1 - astro-ph.CO - hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yi-Fu Cai, Peizhi Du, Jiahang Zhong + M. Sawczuck, H. Beuther, S. Suri, F. Wyrowski, K. M. Menten, J. M. Winters, L. Bouscasse, N. Schneider, T. Csengeri, C. Gieser, S. Li, D. Semenov, I. Skretas, M. R. A. Wells - Magnetic activity of ultracool dwarfs in the LAMOST DR11 - https://arxiv.org/abs/2512.08305 - arXiv:2512.08305v1 Announce Type: new -Abstract: Ultracool dwarfs consist of lowest-mass stars and brown dwarfs. Their interior is fully convective, different from that of the partly-convective Sun-like stars. Magnetic field generation process beneath the surface of ultracool dwarfs is still poorly understood and controversial. To increase samples of active ultracool dwarfs significantly, we have identified 962 ultracool dwarfs in the latest LAMOST data release, DR11. We also simulate the Chinese Space Station Survey Telescope (CSST) low-resolution slitless spectra by degrading the LAMOST spectra. A semi-supervised machine learning approach with an autoencoder model is built to identify ultracool dwarfs with the simulated CSST spectra, which demonstrates the capability of the CSST all-sky slitless spectroscopic survey on the detection of ultracool dwarfs. Magnetic activity of the ultracool dwarfs is investigated by using the H$\alpha$ line emission as a proxy. The rotational periods of 82 ultracool dwarfs are derived based on the Kepler/K2 light curves. We also derive the activity-rotation relation of the ultracool dwarfs, which is saturated around a Rossby number of 0.12. - oai:arXiv.org:2512.08305v1 + Surface image and activity-corrected orbit of the RS CVn binary HR 7275: Disentangling activity tracers + https://arxiv.org/abs/2512.09521 + arXiv:2512.09521v1 Announce Type: new +Abstract: Quantifying stellar parameters and magnetic activity for cool stars in double-lined spectroscopic binaries (SB2) is not straightforward, as both stars contribute to the observed composite spectra and are likely variable. Disentangled component spectra allow a detailed analysis of a component's magnetic activity. + We aim at separating the spectra of the two stellar components of the HR\,7275 SB2 system. Our further aim is a more accurate orbital solution by cleaning the observed radial velocities (RV) from activity perturbations of the spotted primary ("RV jitter") and obtain a surface image of this component. + The Doppler image of the primary shows two large cool spots of size $\approx$20\% of the visible hemisphere plus three smaller spots, each still $\approx$13\% in size. In total, HR\,7275a exhibited an impressive spottedness of $\approx$40\%\ of its entire surface in May-June 2022. The RV is modulated by the rotation of the primary with maximum amplitudes of 320\,\ms\ and 650\,\ms\ for two different modulation behaviors during the 250\,d of our observations. This jitter is primarily caused by the varying asymmetries of the apparent disk brightness due to the cool spots. Its removal resulted in roughly ten times higher precision of the orbital elements. Our snapshot magnetic-field measurements reveal phase-dependent (large-scale) surface fields between +0.6$\pm$2.0\,G at phase 0.1 and $-$15.2$\pm$2.7\,G at phase 0.6, indicating a complex magnetic morphology related to the location of the photospheric spots. We also obtain a logarithmic lithium abundance of 0.58$\pm$0.1 for HR\,7275a, indicating considerable mixing, and 0.16$^{+0.23}_{-0.63}$ for HR\,7275b, which is an extremely low value. + } + oai:arXiv.org:2512.09521v1 astro-ph.SR - astro-ph.IM - cs.LG - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yue Xiang, Shenghong Gu, Dongtao Cao + http://creativecommons.org/licenses/by/4.0/ + \"O. Adebali, M. Weber, K. G. Strassmeier, I. V. Ilyin, M. Steffen, Zs. Kov\'ari - Machine learning classification of baseband data of CHIME FRBs - https://arxiv.org/abs/2512.08308 - arXiv:2512.08308v1 Announce Type: new -Abstract: Fast Radio Bursts (FRBs) are bright millisecond radio pulses. Their origin is still unknown in the field of astronomy. A notable distinction among FRBs is that some sources repeat, while others appear to be non-repeating events. Interestingly, repeating FRBs tend to exhibit broader temporal widths and narrower spectral bandwidths compared to non-repeat events, suggesting they may arise from different physical mechanisms. However, current radio telescopes have limited coverage and sensitivity, which hinders a complete survey with continuous long-term monitoring. This issue makes it difficult to confirm repeat activity and potentially leads to misclassification of repeaters as non- repeaters; these are referred to as repeater candidates. To address this, machine learning techniques have emerged as a useful tool for classifying distinct FRB types in previous studies. In this study, we utilize the CHIME/FRB baseband catalog with three orders of magnitude better time resolution than the intensity catalog. Measured fluences are available in the baseband catalog, while only upper limits are reported in the intensity catalog. We apply machine learning to the baseband catalog to evaluate classification outcomes. We identify 15 repeater candidates among 122 non-repeating FRBs in the baseband catalog. Additionally, our classification identifies 31 sources previously categorized as repeater candidates as non-repeaters, highlighting a significant difference from the prior work. Of these repeater candidates, 14 overlap with previous findings, while 1 is newly identified in this work. Notably, one of our candidates was confirmed as a repeater by CHIME/FRB. Follow-up observations for the 14 candidates are highly encouraged. - oai:arXiv.org:2512.08308v1 - astro-ph.HE + Age, Chemistry, and Kinematics of the Inner Galaxy Revealed by MUSE + https://arxiv.org/abs/2512.09527 + arXiv:2512.09527v1 Announce Type: new +Abstract: The bar/bulge and inner disk are fundamental building blocks of the Milky Way, containing a large fraction of its stellar mass. However, stars in these regions are faint, crowded, and have high extinction, which makes studying their formation and evolution challenging. Using the integral-field spectrograph MUSE with adaptive-optics on the Very Large Telescope, we overcome these limitations and measure accurate ages, chemical abundances, and line-of-sight velocities for 98 main-sequence turn-off and subgiant branch stars with $R_{gc}<3.5$ kpc in Baade's Window. We find that 17% stars have ages younger than 5 Gyr, and the age distribution reveals multiple peaks at 3.1, 4.8, 7.6, and 10.8 Gyr, indicating that star formation in the inner Galaxy occurred in multiple episodes. These stars are predominantly metal-rich but span a broad metallicity range ($-1.2<$[Fe/H]$<+0.6$). The [$\alpha$/Fe]-[Fe/H] distribution shows both $\alpha$-rich and $\alpha$-poor sequences, with most stars being metal-rich and low-[$\alpha$/Fe]. Our results demonstrate that IFUs enable reliable measurements of stellar parameters even in the most crowded regions of the Milky Way, opening a new pathway to study the chemodynamical evolution of the inner Galaxy. + oai:arXiv.org:2512.09527v1 + astro-ph.GA astro-ph.IM - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Mohanraj Madheshwaran, Tetsuya Hashimoto, Tomotsugu Goto, William J. Pearson, Murthadza Aznam, Simon C. -C. Ho, Vignesh V. V. Rao, Sridhar Gajendran + http://creativecommons.org/licenses/by/4.0/ + Zixian Wang (Purmortal), Michael R. Hayden, Sanjib Sharma, Joss Bland-Hawthorn, Anil C. Seth, Gail Zasowski - PolySwyft: sequential simulation-based nested sampling - https://arxiv.org/abs/2512.08316 - arXiv:2512.08316v1 Announce Type: new -Abstract: We present PolySwyft, a novel, non-amortised simulation-based inference framework that unites the strengths of nested sampling (NS) and neural ratio estimation (NRE) to tackle challenging posterior distributions when the likelihood is intractable but a forward simulator is available. By nesting rounds of NRE within the exploration of NS, and employing a principled KL-divergence criterion to adaptively terminate sampling, PolySwyft achieves faster convergence on complex, multimodal targets while rigorously preserving Bayesian validity. On a suite of toy problems with analytically known posteriors of a dim(theta,D)=(5,100) multivariate Gaussian and multivariate correlated Gaussian mixture model, we demonstrate that PolySwyft recovers all modes and credible regions with fewer simulator calls than swyft's TNRE. As a real-world application, we infer cosmological parameters dim(theta,D)=(6,111) from CMB power spectra using CosmoPower. PolySwyft is released as open-source software, offering a flexible toolkit for efficient, accurate inference across the astrophysical sciences and beyond. - oai:arXiv.org:2512.08316v1 - astro-ph.IM - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + Can Clump Properties Predict Core Distribution in Star Formation? A Statistical Analysis of MHD Simulations + https://arxiv.org/abs/2512.09529 + arXiv:2512.09529v1 Announce Type: new +Abstract: Dense cores, the progenitors of stars, are in sub-pc scale and fragmented from pc-scale clumps. However, it is still unclear that how strongly the fragmentation process is affected by the properties of the host clumps, and how these properties influence the core distribution observed in recent millimeter (mm) and sub-mm observations. To systematically investigate this relation, we employed MHD simulations of convergent flows to generate a large sample of clumps and analyzed their properties using various techniques. Alignment parameters were used to quantify core distribution, while energy terms were calculated to assess the influence of gravity, magnetic fields, and turbulence. We found the core distribution only exhibiting weak correlations between alignment parameters and clump properties. For an individual clump, turbulence is believed to significantly contribute to these features by inducing non-homologous collapse and ongoing fragmentation. Nevertheless, for the entire population, more compact core distributions are observed due to the dominance of gravity. Overall, these factors suggest that clump properties are not sufficient to accurately determine core distribution. + oai:arXiv.org:2512.09529v1 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Kilian H. Scheutwinkel, Will Handley, Christoph Weniger, Eloy de Lera Acedo + Wei-An Chen, Seamus D. Clarke, Ya-Wen Tang - Extremely energetic EUV late phase of a pair of C-class flares caused by a non-eruptive sigmoid - https://arxiv.org/abs/2512.08324 - arXiv:2512.08324v1 Announce Type: new -Abstract: The EUV late phase is the second increase of the irradiance of the warm coronal lines during solar flares, and has a crucial impact on the Earth's ionosphere. In this paper, we report on the extremely energetic EUV late phase of a pair of C-class flares (SOL2012-06-17T17:26:11) observed on 2012 June 17 in NOAA active region 11504 by the \textit{Atmospheric Imaging Assembly} (AIA) instrument on board the \textit{Solar Dynamics Observatory} (SDO). The light curves integrated over the flaring region show that a factor of 4.2 more energy is released in the ``warm'' (2$-$3$\times 10^6$~K) temperature passbands (e.g. AIA 335 \AA) during the late phase than during the main peaks. The origin of the emission in this extremely energetic EUV late phase is a non-eruptive sigmoid situated in a multi-polar magnetic field configuration, which is rapidly energised by C-class flares. The sigmoid plasma appears to reach temperatures in excess of $10^7$~K, before cooling to produce the EUV late-phase emission. This is seen in high-temperature passbands (e.g. AIA 131 \AA) and by using differential emission measure analysis. Magnetic extrapolations indicate that the sigmoid is consistent with formation by magnetic reconnection between previously existing J-shaped loops. The sigmoid experienced a fast and a slow cooling stages, both of which were dominated by conductive cooling. The estimated total cooling time of the sigmoid is shorter than the observed value. So, we proposed that the non-eruptive sigmoid, heated by the continuous magnetic reconnection, leads to the extremely energetic EUV late phase. - oai:arXiv.org:2512.08324v1 + Ultimate large-$Rm$ regime of the solar dynamo + https://arxiv.org/abs/2512.09536 + arXiv:2512.09536v1 Announce Type: new +Abstract: For more than fourty years, the quest to understand how large-scale magnetic fields emerge from turbulent flows in rotating astrophysical systems, such as the Sun, has been a major thread of computational astrophysics research. Using a parameter scan and phenomenological analysis of maximally-simplified three-dimensional cartesian magnetohydrodynamic simulations of large-scale nonlinear helical turbulent dynamos, I present results in this Letter that strongly point to an asymptotic ultimate regime of the large-scale solar dynamo, at large magnetic Reynolds numbers $Rm$, involving helicity fluxes between hemispheres. I obtained corresponding numerical solutions at both $Pm>1$ and $Pm<1$, and show that they can currently only be achieved in clean, simplified numerical setups. The analysis further strongly suggests that all global simulations to date lie in a non-asymptotic turbulent MHD regimes highly sensitive to changes in kinetic and magnetic Reynolds numbers. Ideas are presented to attempt to reach this ultimate regime in such "realistic" global spherical models at a reasonable numerical cost. Overall, the results clarify the current state, and some hard limitations of the brute-force numerical modelling approach applied to this, and other similar astrophysical turbulence problems. + oai:arXiv.org:2512.09536v1 astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.GA + physics.flu-dyn + physics.plasm-ph + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Ya Wang, Sargam M. Mulay, Lyndsay Fletcher + Fran\c{c}ois Rincon (IRAP, CNRS, UPS) - Kick & spin: new probes for multi-messenger black-hole mergers in AGNs - https://arxiv.org/abs/2512.08382 - arXiv:2512.08382v1 Announce Type: new -Abstract: Recoiling remnants of black-hole mergers in dense environments can produce bright electromagnetic (EM) counterparts to the gravitational-wave (GW) emission. Significance assessments of such GW-EM candidates are restricted to time and sky-localisation consistency, omitting the physics governing the EM emission process. Different emission mechanisms, however, impose different observability constraints on the remnant black-hole recoil and spin, which are gravitational-wave observables. We present a statistical framework that includes such parameters. We assess the consistency of the GW190521-ZTF19abanrhr pair with two types of emission processes: a Blandford-Znajek jet closely aligned with the final spin axis and a diffusive isotropic flare. Assuming the sky-location of ZTF19abanrhr, we find these mechanisms to be respectively strongly and moderately disfavoured with log-evidences $\log_{10}{\cal I}_{\rm jet} = -1.65$ and $\log_{10}{\cal I}_{\rm diff} = -0.075$. Combining these with odds for a common sky-location $\Omega$ we obtain respective combined odds $\log_{10} {\cal O}_{\Omega,{\rm jet}}= -1.17$ and $\log_{10} {\cal O}_{\Omega,{\rm diff}}= +0.39$ for a true GW-EM coincidence as opposed to a random one. Our method leverages a previously unexplored evidence axis to assess GW-EM associations and constrain both the physics powering flare mechanisms and the properties of AGNs. - oai:arXiv.org:2512.08382v1 - astro-ph.HE - gr-qc - Wed, 10 Dec 2025 00:00:00 -0500 + Observational constraints on New Tsallis holographic energy in Rastall theory + https://arxiv.org/abs/2512.09540 + arXiv:2512.09540v1 Announce Type: new +Abstract: The cosmological implications of New Tsallis holographic dark energy (NTHDE) in Rastall theory have been studied. Using the data set that includes DESI BAO (DR2), PantheonPlus SNe Ia, H(z) measurements, and BBN and the MCMC analysis, the key cosmological and model-specific parameters are constrained. The result is compared with that of the {\Lambda}CDM model indicating that in addition to providing a viable dynamical dark energy framework, predictions for H(z) are slightly more consistent with intermediate-redshift observations. Generally, the model remains compatible with current data and offers testable deviations from {\Lambda}CDM for upcoming surveys. It is also seen that when the energy density of quantum fields in vacuum, exposed by NTHDE, is combined with the Rastall correction term to the general relativity, a plausible candidate for dynamical dark energy is obtained that mimic the current value of the dark energy density parameter reported in the {\Lambda}CDM model. The latter cannot be repeated by NTHDE alone. The study also confirms previous theoretical and observational constraints on the Rastall parameter obtained by focusing on the thermodynamics, early universe, pulsars, and the early-type galaxies. + oai:arXiv.org:2512.09540v1 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Samson H. W. Leong, Juan Calder\'on Bustillo + http://creativecommons.org/licenses/by/4.0/ + N. Sadeghnezhad, R. Jalalzadeh, Z. Davari, B. Afshar - Chemical analysis of the Milky Way's Nuclear Star Cluster: Evidence for a metallicity gradient - https://arxiv.org/abs/2512.08387 - arXiv:2512.08387v1 Announce Type: new -Abstract: The Milky Way nuclear star cluster (MWNSC) is located together with its surrounding nuclear stellar disc (MWNSD) in the Galactic centre and they dominate the gravitational potential within the inner 300\,pc. However, the formation and evolution of both systems and their possible connections are still under debate. We reanalyse the low-resolution KMOS spectra in the MWNSC with the aim to improve the stellar parameters ($\rm T_{eff}$, $\rm \log\,g$, and $\rm [M/H])$ for the MWNSC. We use an improved line-list, especially dedicated for cool M giants allowing to improve the stellar parameters and to obtain in addition global $\rm \alpha$-elements. A comparison with high-resolution IR spectra (IGRINS) gives very satisfactory results pinning down the uncertainties to $\rm T_{eff} \simeq 150\,K$, $\rm log\,g \simeq 0.4\,dex$, and $\rm [M/H] \simeq 0.2\,dex$. Our $\rm \alpha$-elements agree within 0.1\,dex compared to the IGRINS spectra. We obtain a high-quality sample of 1140 M giant stars where we see an important contribution of a metal-poor population ($\rm \sim 20\,\%$) centered at $\rm [M/H] \simeq -0.7\,dex$ while the most dominant part comes from the metal-rich population with $\rm [M/H] \simeq 0.26\,dex$. We construct a metallicity map and find a metallicity gradient of $\rm \sim -0.1 \pm 0.02 \,dex/pc$ favouring the inside-out formation scenario for the MWNSC. - oai:arXiv.org:2512.08387v1 - astro-ph.GA - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + The Response of Planetary Atmospheres to the Impact of Icy Comets III: Impact Driven Atmospheric Escape + https://arxiv.org/abs/2512.09556 + arXiv:2512.09556v1 Announce Type: new +Abstract: In an Earth-analogue atmosphere, water vapour is a key carrier of hydrogen in the lower atmosphere with its transport above the tropopause controlling the atmospheric hydrogen escape rate. On the Earth, this escape is limited by transport though the tropospheric cold trap where water vapour condenses. However, on a tidally-locked exoplanet, the strong day-night temperature gradient drives a global-scale circulation. This circulation could rapidly transport water through the cold trap, potentially increasing hydrogen escape and impacting the composition of potentially habitable worlds. We couple cometary impact and planetary atmospheric models to simulate water-depositing impacts with both a tidally-locked and Earth-analogue atmosphere and quantify how atmospheric circulations transport water from the impact site to high altitudes where it can potentially drive escape. The global nature of the atmospheric circulations on a tidally-locked world enhances hydrogen escape, with both our unimpacted tidally-locked and Earth-analogue atmospheres exhibiting similar mass loss rates despite the tidally-locked atmosphere being bpth cooler and drier near the surface. When considering the effects of a cometary impact, we find an order of magnitude difference in peak escape rates between impacts on the day-side ($\Phi_{\mathrm{escape}}=1.33\times10^{10}\,\mathrm{mol\,mth^{-1}}$) and night-side ($\Phi_{\mathrm{escape}}=1.51\times10^{9}\,\mathrm{mol\,mth^{-1}}$) of a tidally-locked atmosphere, with the latter being of the same order of magnitude as the peak escape rate found for an impact with an Earth-analogue atmosphere ($\Phi_{\mathrm{escape}}=2.7\times10^{9}\,\mathrm{mol\,mth^{-1}}$). Our results show the importance of understanding the underlying atmospheric circulations when investigating processes, such as hydrogen escape, which depend upon the vertical advective mixing and transport. + oai:arXiv.org:2512.09556v1 + astro-ph.EP + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - M. Schultheis, L. Serrano, B. Thorsbro, F. Nogueras-Lara, A. Feldmeier-Krause, G. Nandakumar, K. Fiteni, M. C. Sormani + Felix Sainsbury-Martinez, Greg Cooke, Catherine Walsh - Photochemistry of interstellar ice forming Complex Organic Molecules - https://arxiv.org/abs/2512.08413 - arXiv:2512.08413v1 Announce Type: new -Abstract: Astrochemistry is a well-established multidisciplinary field devoted to study molecules in space. While most astrochemists are oriented to observe molecules in the gas phase and reproduce their abundances by modeling the physical conditions of the medium, the microscopic dust particles wandering in the interstellar medium deserve the attention of a smaller community. Radiation and thermally-driven processes taking place in the bare dust, and particularly in dust particles covered by ice mantles, are mimicked in the laboratory. In addition to water, interstellar ice contains other simple species. In this Review we present our current knowledge on ice photochemistry and thermal processing that ultimately leads to formation of complex organic molecules (COMs). Numerous COMs are of astrobiological interest and match those present in comets and asteroids. Upon impact of these minor bodies, water and COMs were delivered to the earth and might have intervened in the first prebiotic reactions. - oai:arXiv.org:2512.08413v1 - astro-ph.GA - astro-ph.EP - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + 3-Dimensional WIMP Effective Velocity Distribution + https://arxiv.org/abs/2512.09567 + arXiv:2512.09567v1 Announce Type: new +Abstract: In this talk, I discussed a 3-dimensional "effective" velocity distribution of Weakly Interacting Massive Particles (WIMPs), which, instead of the theoretically predicted velocity distribution of "entire" Galactic Dark Matter particles, describes the actual velocity distribution of WIMPs "scattering off" (specified) target nuclei in an underground detector. Based on numerical results carried out by our double Monte Carlo scattering-by-scattering simulation of 3-dimensional elastic WIMP-nucleus scattering, an (asymmetric) "forward-backward asymmetry" was also demonstrated. + oai:arXiv.org:2512.09567v1 + astro-ph.HE + hep-ph + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1038/s41570-025-00729-z - Nat. Rev. Chem., 9, 537-552 (2025) - Guillermo M. Mu\~noz Caro, H\'ector Carrascosa de Lucas, Rafael Mart\'in-Dom\'enech + http://creativecommons.org/licenses/by-sa/4.0/ + Chung-Lin Shan - Collisional rate coefficients for OH-H$_2$ at high temperatures - https://arxiv.org/abs/2512.08420 - arXiv:2512.08420v1 Announce Type: new -Abstract: OH is a cornerstone molecule in the chemistry of interstellar and circumstellar media and is ubiquitously detected in warm gas thanks to its infrared rotational lines. However, the excitation processes of OH remain poorly characterized. We provide a new set of collisional rate coefficients for OH with H$_2$, expanding the existing data to $j$ levels up to $j=15/2$ and temperatures up to 750 K. These rate coefficients are obtained from state-to-state collision cross sections calculated by means of well-converged close-coupling quantum scattering calculations for collisions of OH with para- and ortho-H$_2$ with energies up to 1700 cm$^{-1}$ ($\simeq 2450$ K). We reproduce the rate coefficients computed by Klos et al. (2017) and extend their results to higher temperatures and higher rotational levels of OH. The de-excitation rate coefficients are lower in collisions with para-H$_2$ ($j_{\rm H_2} = 0$) due to the absence of a quadrupole moment, but this difference decreases at higher temperatures. We find that the rate coefficients follow scaling relations with the energy gap between the upper and lower levels of a given transition, which allows extrapolation to higher OH rotational states $j_{\rm OH}$. As a first application, we show that under astrophysical conditions typical of warm and dense gas around nascent stars, the populations of low-$j_{\rm OH}$ states are dominated by collisions, even when chemical pumping is included. The full set of rate coefficients is made available in the LAMDA database. - oai:arXiv.org:2512.08420v1 - astro-ph.GA + WASP-12, shrouded in mystery or just cold gas? + https://arxiv.org/abs/2512.09593 + arXiv:2512.09593v1 Announce Type: new +Abstract: Observations of the planet-hosting star WASP-12 show a distinctive depression in the \ion{Mg}{ii} and \ion{Ca}{ii} resonance lines. This has been interpreted as a marker of atmospheric loss from the close-in hot Jupiter WASP-12b and the resulting formation of a gas torus around the star. In this paper we quantify the \ion{Mg}{ii} absorption from this torus, compared to that provided by the stellar wind, the stellar astrosphere and the ISM. To do this we piece together the full density profile of \ion{Mg}{ii} from WASP-12 to an observer on Earth using a combination of hydrodynamical simulations and observations. We find that the bulk of the gas along the line of sight is contained within a dense torus close to WASP-12. However, the temperatures in this torus are sufficient to promote Mg into a doubly (\ion{Mg}{iii}) or higher ionized state. As a result, the singly ionized fraction (\ion{Mg}{ii}) is low. We find that most of the \ion{Mg}{ii} is not in the torus but in the ISM. Despite this, the total column density of \ion{Mg}{ii} is two orders of magnitude lower than required to explain observations of the system. To resolve this discrepancy, we note that the torus gas is at a temperature where it will cool efficiently. We speculate that the onset of the cooling instability will cause the torus to fragment, forming cold clumps with a higher fraction of \ion{Mg}{ii}, capable of explaining the observed absorption. + oai:arXiv.org:2512.09593v1 + astro-ph.EP astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Zeno van den Heuvel, Beno\^it Tabone, Ewine F. van Dishoeck, Gerrit C. Groenenboom, Ad van der Avoird + Simon Daley-Yates, Ricarda Beckmann, Lewis McCallum, Moira Jardine, Andrew Cameron - Self-lensing flares from black hole binaries V: systematic searches in LSST - https://arxiv.org/abs/2512.08427 - arXiv:2512.08427v1 Announce Type: new -Abstract: The Vera C. Rubin Observatory has now seen first light, and over a 10 year duration, LSST is projected to catalogue tens of millions of quasars, many of which are expected to be associated with sub-parsec supermassive black hole binaries (SMBHBs). Out of these SMBHBs, up to thousands of relatively massive binary-quasars are expected to exhibit gravitational self-lensing flares (SLFs) that last for at least 20-30 days. We assess the effectiveness of the Lomb-Scargle (LS) periodogram and matched filters (MFs) as methods for systematic searches for these binaries, using toy-models of hydrodynamical, Doppler, and self-lensing variability from equal-mass, eccentric SMBHBs. We inject SLFs into random realizations of damped random walk (DRW) lightcurves, representing stochastic quasar variability, and compute the LS periodogram with and without the SLF. We find that periodograms of SLF+DRW light-curves do not have maximum peak heights that could not arise from DRW-only periodograms. On the other hand, the matched filter signal-to-noise ratio (SNR) can distinguish SLFs from noise even with LSST-like cadences and DRW noise. Furthermore, we develop a three-step procedure with matched filters, which can also recover injected binary parameters from these light-curves. We expect this method to be computationally efficient enough to be applicable to millions of quasar light-curves in LSST. - oai:arXiv.org:2512.08427v1 - astro-ph.HE - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + First Resolution of a Main Sequence G-Star Astrosphere Using Chandra + https://arxiv.org/abs/2512.09613 + arXiv:2512.09613v1 Announce Type: new +Abstract: We report resolution of a halo of X-ray line emission surrounding the Zero Age Main Sequence (ZAMS) G8.5V star HD 61005 by Chandra ACIS-S. Located only 36.4 pc distant, HD 61005 is young (approx. 100 Myr), x-ray bright (300 times Solar), observed with nearly edge-on geometry, and surrounded by Local Interstellar Medium (LISM) material denser than in the environ of the Sun. HD 61005 is known to harbor large amounts of circumstellar dust in a dense ecliptic plane full of mm-sized particles plus attached, extended wing like structures full of micron sized particles, which are evidence for a strong LISM-dust disk interaction. These properties aided our ability to resolve the 220 au wide astrosphere of HD61005, the first ever observed for a main sequence G-star. The observed x-ray emission morphology is roughly spherical, as expected for an astrospheric structure dominated by the host star. The Chandra spectrum of HD 61005 is a combination of a hard stellar coronal emission (T=8 MK) at Lx = 6 x10e29 erg per sec, plus an extended halo contribution at Lx = 1x10e29 erg per sec dominated by charge exchange (CXE) lines, such as those of OVIII and NeIX. The Chandra CXE x-ray morphology does not track the planar dust morphology but does extend out roughly to where the base of the dust wings begins. We present a toy model of x-ray emission produced by stellar wind (SW)-LISM CXE interactions, similar to the state of the young Sun when it was approximately 100 Myrs old (Guinan and Engle 2007), and transiting through an approximately 1000 times denser part of the interstellar medium (ISM) such as a Giant Molecular Cloud (Stern 2003, Opher and Loeb 2024). + oai:arXiv.org:2512.09613v1 + astro-ph.SR + astro-ph.EP + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Kevin Park, Zoltan Haiman, Chengcheng Xin, Tzuken Shen, Ashley Villar, Jordy Davelaar + C. M. Lisse, S. J. Wolk, B. Snios, R. L. McNutt, Jr., J. D. Slavin, R. A. Osten, D. C Hines, J. H. Debes, D. Koutroumpa, V. Kharchenko, J. L. Linsky, P. Brandt, M. Horanyi, H. M. Guenther, E. F. Guinan, S. Redfield, P. C. Frisch, K. Dennerl, V. Kashyap, K. G. Kislyakova, Y. R. Fernandez, E. Provornikova, M. A. MacGregor, C. H. Chen, L. Paxton, K. Dialynas, L. Gu - Photon Dynamics and Collision Risks in Relativistic Spaceflight: A Comparative Study of Methods and Implications - https://arxiv.org/abs/2512.08447 - arXiv:2512.08447v1 Announce Type: new -Abstract: This dissertation explores the dynamics of relativistic spaceflight, focusing on the risks associated with collisions and photon interactions as a spacecraft approaches velocities near the speed of light. The study emphasizes two primary collision types: (1) collisions with interstellar dust and particles, and (2) interactions with cosmic molecules, specifically hydrogen. Using principles of energy conservation and relativistic mechanics, the energy transfer from these collisions is calculated, showing that even small particles can impart massive energy at relativistic speeds. The dissertation also examines the impact of the cosmic microwave background (CMB) radiation, particularly its blue-shifting effect at high velocities, which influences photon interactions with the spacecraft. Additionally, the Schwinger limit, which sets an upper bound on the electromagnetic field strength for sustained relativistic travel, is discussed in the context of photon-induced pair production. Lastly, advanced photon interactions, such as Compton scattering, are analyzed for their role in thermal management and spacecraft design. The findings highlight the importance of shielding, thermal regulation, and collision avoidance strategies in the design of spacecraft for interstellar travel, offering insights into the potential challenges and solutions for achieving relativistic spaceflight. - oai:arXiv.org:2512.08447v1 + The impact of AGN environmental effects on testing general relativity with space-borne gravitational wave detector + https://arxiv.org/abs/2512.09635 + arXiv:2512.09635v1 Announce Type: new +Abstract: The space-borne gravitational wave detectors such as TianQin offers a new window to test General Relativity by observing the early inspiral phase of stellar-mass binary black holes. A key concern arises if these stellar-mass binary black holes reside in gaseous environments such as active galactic nucleus accretion disks, where environmental effects imprint detectable modulations on the gravita- tional waveform. Using Bayesian inference on simulated signals containing both environmental and dipole deviation, we have assessed the extent to which the presence of environmental effects affects the detectability of dipole radiation. Our results demonstrate that even in the presence of strong environmental coupling, the dipole parameter can be recovered with high precision, and the evidence for dipole radiation remains distinguishable. Crucially, we find that the existence of environmental effects does not fundamentally impede the identification of dipole radiation, provided both effects are simultaneously modelled in the inference process. This study establishes that future tests of modified gravity with space-borne observatories can remain robust even for sources in astrophysical environments. + oai:arXiv.org:2512.09635v1 astro-ph.HE gr-qc - physics.space-ph - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Li Kai Wen, Joao Rodrigues + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Xiangyu Lyu, Hongyu Chen, En-Kun Li, Yi-Ming Hu - Delving into the depths of NGC 3783 with XRISM III. Birth of an ultrafast outflow during a soft flare - https://arxiv.org/abs/2512.08448 - arXiv:2512.08448v1 Announce Type: new -Abstract: The 2024 X-ray/UV observation campaign of NGC 3783, led by XRISM, revealed the launch of an ultrafast outflow (UFO) with a radial velocity of 0.19c (57000 km/s). This event is synchronized with the sharp decay, within less than half a day, of a prominent soft X-ray/UV flare. Accounting for the look-elsewhere effect, the XRISM Resolve data alone indicate a low probability of 2e-5 that this UFO detection is due to random chance. The UFO features narrow H-like and He-like Fe lines with a velocity dispersion of 1000 km/s, suggesting that it originates from a dense clump. Beyond this primary detection, there are hints of weaker outflow signatures throughout the rise and fall phases of the soft flare. Their velocities increase from 0.05c to 0.3c over approximately three days, and they may be associated with a larger stream in which the clump is embedded. The radiation pressure is insuffcient to drive the acceleration of this rapidly evolving outflow. The observed evolution of the outflow kinematics instead closely resembles that of solar coronal mass ejections, implying magnetic driving and, conceivably, reconnection near the accretion disk as the likely mechanisms behind both the UFO launch and the associated soft flare. - oai:arXiv.org:2512.08448v1 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Accretion bottleneck in protoplanetary discs: the role of the stellar spin + https://arxiv.org/abs/2512.09638 + arXiv:2512.09638v1 Announce Type: new +Abstract: We investigate angular momentum transport and accretion properties in a sample of protoplanetary discs with dynamical measurements of stellar masses, disc masses, and scale radii. From these data we infer effective $\alpha$-viscosities, finding a remarkably broad range spanning over three orders of magnitude. This spread correlates with the stellar rotation period: systems with shorter periods exhibit significantly lower accretion rates, suggesting that they are undergoing at least temporary episodes of accretion bottleneck. We interpret this behaviour within the framework of magnetospheric accretion models, where the transition between steady accretion and the propeller regime is set by the relative locations of the co-rotation and magnetospheric radii. Our results indicate that stellar spin is a key parameter in regulating mass transfer from the disc to the star, and provide new evidence that the observed dispersion in $\alpha$ reflects transitions between distinct accretion states rather than differences in global disc properties. + oai:arXiv.org:2512.09638v1 + astro-ph.EP + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.1051/0004-6361/202557189 - A&A, 704, A146 (2025) - Liyi Gu, Keigo Fukumura, Jelle Kaastra, Megan Eckart, Ralf Ballhausen, Ehud Behar, Camille Diez, Matteo Guainazzi, Timothy Kallman, Erin Kara, Chen Li, Missagh Mehdipour, Misaki Mizumoto, Shoji Ogawa, Christos Panagiotou, Matilde Signorini, Atsushi Tanimoto, Keqin Zhao, Hirofumi Noda, Jon Miller, Satoshi Yamada + Cristiano Longarini, Cathie Clarke - Globular Cluster Systems in Dwarf Galaxies: Catalogs and Comparisons - https://arxiv.org/abs/2512.08453 - arXiv:2512.08453v1 Announce Type: new -Abstract: The connection between a galaxy's total globular cluster system (GCS) mass and its halo mass has been studied for decades and it has been found that galaxies at nearly all observed masses adhere to a linear scaling relation between these properties. However, while we have ample, homogeneous data for galaxies with halo masses $M_h \gtrsim 10^{10} M_{\odot}$ the data available for low-mass galaxies is more sparse, and both GCS mass and halo mass estimates are determined using varying methodologies. This work compiles all available literature data for dwarf galaxies with confident stellar mass and GC count estimates, and converts these estimates to GCS masses and peak halo masses using a standard conversion. This allows for a consistent comparison of these masses to be made and a complete study of the behaviour of the $M_{GCS}-M_h$ relation to be conducted. We compare the positions of classical dwarfs on the scaling relation to that of ultra diffuse galaxies and extremely low-surface brightness galaxies and find that these non-classical dwarfs have, on average, systematically higher GC specific frequencies. This also makes them, on average, systematically positively offset from the $M_{GCS}-M_h$ relation, driving much of the high-$M_{GCS}$ scatter observed. - oai:arXiv.org:2512.08453v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Correlations of Simulated Black-Hole Movies Reveal Extreme-Lensing Signatures + https://arxiv.org/abs/2512.09641 + arXiv:2512.09641v1 Announce Type: new +Abstract: A black hole's gravitational pull can deflect light rays to an arbitrary degree. As a result, any source fluctuation near the black hole creates multiple lagged images on an observer's screen. For optically thin stochastic emission, these light echoes give rise to correlations of brightness fluctuations across time-dependent images (movies). The correlation pattern disentangles source-specific characteristics from universal features dictated by general relativity. This picture has motivated a proposal to use the two-point image correlation function as a probe of extreme gravitational lensing in upcoming black-hole imaging campaigns. In this work, we test the feasibility of this method by computing the two-point correlation function of brightness fluctuations in a black-hole movie of state-of-the-art realism. The movie is generated by ray tracing a general relativistic magnetohydrodynamic simulation, which can then be blurred to any angular resolution. At an effective resolution expected to be achieved by next-generation terrestrial very-long-baseline interferometric arrays, the lensing signatures appear in neither time-averaged images nor light-curve autocorrelations. However, we demonstrate that they are clearly visible in the more fine-grained two-point image correlation function. Our positive findings motivate a more comprehensive investigation into the instrument specifications and inference techniques needed to resolve extreme lensing effects through correlations. + oai:arXiv.org:2512.09641v1 + astro-ph.HE + astro-ph.IM + gr-qc + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Veronika Dornan, William E. Harris + Barbora Bezd\v{e}kov\'a, Shahar Hadar, George Wong, Maciek Wielgus - J-PAS: First Identification, Physical Properties and Ionization Efficiency of Extreme Emission Line Galaxies - https://arxiv.org/abs/2512.08484 - arXiv:2512.08484v1 Announce Type: new -Abstract: Extreme emission line galaxies (EELGs) are key tracers of intense star formation and potential analogues of the sources that reionized the early Universe. Their low-redshift counterparts offer a unique opportunity to study the physical conditions that enable high ionizing-photon escape fractions. We present a robust method to photometrically identify EELGs in the J-PAS survey, which provides 56 optical bands over 8500 deg^2. Using data from a fully observed 30 deg^2 region, we combine narrow-band equivalent widths with machine-learning techniques to select galaxies with emission lines above 300 {\AA}. The method achieves 95% purity and 96% completeness for $i_\mathrm{SDSS}<22.5$ mag. We identify 917 EELGs up to $z=0.8$; spectroscopic cross-matching with DESI/DR1 confirms the reliability of our redshifts and emission-line measurements. The selected galaxies show strong correlations between $\xi_\mathrm{ion}$ and EW([OIII]), consistent with previous low- and high-z studies. Most sources exceed the ionizing efficiency threshold required for reionization, reinforcing their role as local analogues of early-Universe galaxies. - oai:arXiv.org:2512.08484v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + An Orbital House of Cards: Frequent Megaconstellation Close Conjunctions + https://arxiv.org/abs/2512.09643 + arXiv:2512.09643v1 Announce Type: new +Abstract: The number of objects in orbit is rapidly increasing, primarily driven by the launch of megaconstellations, an approach to satellite constellation design that involves large numbers of satellites paired with their rapid launch and disposal. While satellites provide many benefits to society, their use comes with challenges, including the growth of space debris, collisions, ground casualty risks, optical and radio-spectrum pollution, and the alteration of Earth's upper atmosphere through rocket emissions and reentry ablation. There is substantial potential for current or planned actions in orbit to cause serious degradation of the orbital environment or lead to catastrophic outcomes, highlighting the urgent need to find better ways to quantify stress on the orbital environment. Here we propose a new metric, the CRASH Clock, that measures such stress in terms of the time it takes for a catastrophic collision to occur if there are no collision avoidance manoeuvres or there is a severe loss in situational awareness. Our calculations show the CRASH Clock is currently 2.8 days, which suggests there is now little time to recover from a wide-spread disruptive event, such as a solar storm. This is in stark contrast to the pre-megaconstellation era: in 2018, the CRASH Clock was 121 days. + oai:arXiv.org:2512.09643v1 + astro-ph.EP + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - A. Gim\'enez-Alc\'azar, R. Amor\'in, J. M. V\'ilchez, A. Hern\'an-Caballero, M. Gonz\'alez-Otero, A. Arroyo-Polonio, J. Iglesias-P\'aramo, A. Lumbreras-Calle, J. A. Fern\'andez-Ontiveros, L. Bonatto, R. M. Gonz\'alez Delgado, C. Kehrig, A. Torralba, P. T. Rahna, Y. Jim\'enez-Teja, I. M\'arquez, I. Breda, A. \'Alvarez-Candal, R. Abramo, J. Alcaniz, N. Benitez, S. Bonoli, S. Carneiro, J. Cenarro, D. Crist\'obal-Hornillos, R. Dupke, A. Ederoclite, C. Hern\'andez-Monteagudo, A. Mar\'in-Franch, C. Mendes de Oliveira, M. Moles, L. Sodr\'e Jr., K. Taylor, J. Varela, H. V\'azquez Rami\'o + http://creativecommons.org/licenses/by-sa/4.0/ + Sarah Thiele, Skye R. Heiland, Aaron C. Boley, Samantha M. Lawler - Relativistic MHD simulations of merging and collapsing stars and effects on GRB transient - https://arxiv.org/abs/2512.08489 - arXiv:2512.08489v1 Announce Type: new -Abstract: Compact binary mergers and the collapse of massive stars can produce intense transients observable across high-energy wavelengths. Events such as gamma-ray bursts and kilonova emissions are often accompanied by gravitational wave detections, making them crucial sources for multimessenger astrophysics. To explore these phenomena theoretically, state-of-the-art approaches of General Relativistic magnetohydrodynamic simulations are used. We present recent findings from our simulations, and discuss observational consequences of the stellar/post-merger environment on the gamma ray burst prompt emission properties. - oai:arXiv.org:2512.08489v1 + A jet bent by a stellar wind in the black hole X-ray binary Cygnus X-1 + https://arxiv.org/abs/2512.09645 + arXiv:2512.09645v1 Announce Type: new +Abstract: Jets provide an important channel for kinetic feedback from accreting black holes into their environment, without which models of the formation of large-scale structure in the universe fail to reproduce the observed properties of galaxies. Hence, an accurate measurement of jet power is critical for understanding black hole growth through accretion and also for quantifying the impact of kinetic feedback. However, the absence of instantaneous jet power measurements has precluded direct comparisons with the accretion luminosity, forcing kinetic feedback models to rely on ad hoc assumptions about how much jet power is released per accreted amount of mass. Here we report the detection of stellar wind-induced bending of the jets in the black hole X-ray binary Cygnus X-1, using 18 years of high-resolution radio imaging. By modeling jet-wind interactions, we determine the current kinetic instantaneous power of the jet to be log$_{10}(L_{\rm jet}/{\rm erg\,s}^{-1}) = 37.3_{-0.2}^{+0.1}$, comparable to the accretion energy determined from its bolometric X-ray luminosity. This result critically places prevailing assumptions about the energetics of black hole powered jets in both galaxy formation simulations, and in scaling models of black hole accretion, on a firm empirical footing. + oai:arXiv.org:2512.09645v1 astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Agnieszka Janiuk, Gerardo Urrutia, Joseph Saji, Piotr Plonka + Steve Prabu, James C. A. Miller-Jones, Arash Bahramian, Valenti Bosch-Ramon, Sebastian Heinz, Steven J. Tingay, Callan M. Wood, Alexandra Tetarenko, Tyrone N. O'Doherty, Valeriu Tudose - Investigating ionising sources and the complex interstellar medium of GHZ2 at $z=12.3$ - https://arxiv.org/abs/2512.08490 - arXiv:2512.08490v1 Announce Type: new -Abstract: An accurate characterisation of the physical properties of galaxies at cosmic dawn is key to understanding the origin of the high abundance of UV-bright galaxies at z$\gtrsim$10. We exploit deep NIRSpec PRISM observations of GHZ2 to constrain the sources of ionising radiation and the properties of the ISM in this bright, compact, and highly ionising galaxy at z=12.3. We measure with high significance the prominent N IV, C IV, He II, O III, C III, O II, and Ne III emission features previously detected in shallower observations, and confirm the detection of the N III] $\lambda 1750$ multiplet, yielding tight constraints on the N/O ratio, which is found to be $\simeq$2 times the solar value. We also detect the Mg II $\lambda 2800$, [Fe IV] $\lambda 2833$ and Si II $\lambda 1812$ doublets, the H8+HeI $\lambda\lambda 3889$ blend, and the Si IV+O IV] $\lambda\lambda 1400$ absorption complex. The O III $\lambda 3133$ fluorescence line is only detected in the first observing epoch, implying variability on a rest-frame time span of 19 days, strongly suggesting the presence of an active nucleus. Combining the NIRSpec dataset with available optical and far-infrared constraints from MIRI and ALMA, we show that the emission spectrum of GHZ2 cannot be reproduced by single-density spectro-photometric models. Multi-zone photoionisation modelling performed with the HOMERUN code demonstrates that star formation must be occurring in a strongly stratified ISM, where both low-/intermediate-density gas and high-density regions (log($n_e$/cm$^{-3}) \gtrsim 4$) coexist. The GHZ2 emission landscape is consistent with either a composite star-formation plus AGN scenario, or with star formation occurring in a combination of radiation- and matter-bounded regions. Purely radiation-bounded stellar models fail to reproduce the observed He II emission, making an additional hard ionising component unavoidable. - oai:arXiv.org:2512.08490v1 + No evidence for accretion around the intermediate-mass black hole in Omega Centauri + https://arxiv.org/abs/2512.09649 + arXiv:2512.09649v1 Announce Type: new +Abstract: For over a decade, both theoretical predictions and observational studies have suggested that $\omega$ Centauri ($\omega$ Cen), the most massive Milky Way globular cluster, might harbor an intermediate-mass black hole (IMBH). Recently, identification of fast-moving stars in the core of $\omega$ Cen provided the strongest evidence to date for the presence of such an IMBH. One of the key questions in the study of IMBHs is their accretion efficiency, which determines their radio and X-ray signatures. We investigate the accretion signature of the IMBH in $\omega$ Cen with ultra-deep radio continuum observations of the central region of the cluster. Using approximately 170 hours of Australia Telescope Compact Array observations, we achieve a root mean square noise of 1.1 $\mu$Jy at 7.25 GHz, making this the most sensitive radio image of the cluster to date. We detect no radio emission at any of the proposed centers of the cluster, imposing stringent constraints on the presence of an accreting IMBH in $\omega$ Cen. Considering the fundamental plane of black hole activity, our findings indicate that the accretion efficiency around the black hole is exceptionally low (with a conservative 3-$\sigma$ upper limit of $\epsilon \lesssim 4\times10^{-3}$). + oai:arXiv.org:2512.09649v1 + astro-ph.HE astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - M. Castellano, L. Napolitano, B. Moreschini, A. Calabr\`o, L. Christensen, M. Llerena, T. J. L. C. Bakx, F. Belfiore, D. Bevacqua, M. Dickinson, A. Fontana, G. Gandolfi, T. Gasparetto, A. Marconi, S. Mascia, E. Merlin, T. Morishita, T. Nanayakkara, D. Paris, L. Pentericci, B. P\'erez-D\'iaz, G. Roberts-Borsani, S. Rojas Ruiz, P. Santini, T. Treu, E. Vanzella, B. Vulcani, X. Wang, I. Yoon, J. Zavala + Angiraben D. Mahida, Arash Bahramian, James C. A. Miller Jones, Susmita Sett, Kristen Dage, Jay Strader, Timothy J. Galvin, Alessandro Paduano - Supervised Classification of LEO Debris Families Using Multi-Set Proper Elements - https://arxiv.org/abs/2512.08495 - arXiv:2512.08495v1 Announce Type: new -Abstract: Machine learning techniques using proper elements to reconnect families of satellite fragmentation debris have recently advanced, becoming key to space sustainability and domain awareness. However, an evolving circumterrestrial environment may limit their applicability, particularly when models are trained on outdated debris representations. In this work, we devise a computational pipeline using synthetic fragmentation data from explosive breakup events, generated via a Standard Breakup Model and propagated under a high-fidelity dynamical model. Proper elements are extracted using adapted algorithms for modified equinoctial (MEE), Poincar'e (PNC), and quaternion (QTN) sets. - Extending beyond previous approaches limited to MEE space, we include PNC and QTN sets to broaden the dynamical fingerprints available to the classifier. Neural networks trained on various element combinations are used to determine if fragment pairs share a parent. Crucially, we identify a fundamental limitation when applying standard quaternion sets to neural networks: the loss of orbital size information during feature normalization. We introduce an augmented representation (QTN$_p$) that explicitly restores the semi-latus rectum, improving accuracy from 0.31 to 0.60 compared to the standard set. In synthetic Starlink-like LEO experiments, expanding proper-element sets generally improves discrimination. The best model, using a joint feature set (MEE + PNC + QTN), achieves an ROC-AUC of 0.858 compared to 0.789 for the MEE-only baseline, alongside higher accuracy and F1 scores. - oai:arXiv.org:2512.08495v1 + Cosmic-Ray Bath in a Past Supernova Gives Birth to Earth-Like Planets + https://arxiv.org/abs/2512.09660 + arXiv:2512.09660v1 Announce Type: new +Abstract: A key question in astronomy is how ubiquitous Earth-like rocky planets are. The formation of terrestrial planets in our solar system was strongly influenced by the radioactive decay heat of short-lived radionuclides (SLRs), particularly $^{26}$Al, likely delivered from nearby supernovae. However, current models struggle to reproduce the abundance of SLRs inferred from meteorite analysis without destroying the protosolar disk. We propose the `immersion' mechanism, where cosmic-ray nucleosynthesis in a supernova shockwave reproduces estimated SLR abundances at a supernova distance ($\sim$1 pc), preserving the disk. We estimate that solar-mass stars in star clusters typically experience at least one such supernova within 1 pc, supporting the feasibility of this scenario. This suggests solar-system-like SLR abundances and terrestrial planet formation are more common than previously thought. + oai:arXiv.org:2512.09660v1 astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.GA + astro-ph.HE + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Michael Ling, Yang Yang + 10.1126/sciadv.adx7892 + Science Advances (2025) + Ryo Sawada, Hiroyuki Kurokawa, Yudai Suwa, Tetsuo Taki, Shiu-Hang Lee, Ataru Tanikawa - Radiation pressure instability: from heart-beat states in black hole binary systems to Quasars and Changing-Look AGN - https://arxiv.org/abs/2512.08502 - arXiv:2512.08502v1 Announce Type: new -Abstract: Radiation-pressure instability was identified soon after the seminal classical accretion disk models of Shakura-Sunyaev and Novikov-Thorne, yet its full implications remain an active area of investigation. These models form the backbone of our understanding of accretion onto compact objects and successfully describe the phenomenology of black hole and neutron star X-ray binaries, as well as luminous active galactic nuclei (AGN), in the regime of high mass accretion rates. At luminosities approaching a significant fraction of the Eddington limit (L/LEdd > 0.1), standard thin disks are predicted to become thermally unstable due to the dominance of radiation pressure. This prediction has found empirical support in several Galactic stellar-mass black hole systems, where the instability manifests as quasi-periodic, large-amplitude luminosity oscillations, so-called "heartbeat states", and has been proposed as a driver of observed signatures of deterministic chaos in accretion-driven light curves. The scope of radiation-pressure-induced variability extends beyond stellar-mass black holes: both black holes across mass scales and accreting neutron stars can exhibit related behavior, though the presence of a boundary layer in neutron stars adds complexity and offers a unique laboratory for testing the interplay between accretion dynamics and the central object. On extragalactic scales, the instability has been invoked to explain the duty cycles and apparent short lifetimes of radio-loud AGN, as well as the dramatic spectral-state transitions seen in Changing-Look AGN. (...) - oai:arXiv.org:2512.08502v1 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Numerical simulations of astrophysical dynamos and applications to giant planets + https://arxiv.org/abs/2512.09725 + arXiv:2512.09725v1 Announce Type: new +Abstract: Magnetic fields pervade astrophysical systems and strongly influence their dynamics. Because magnetic diffusion is usually much faster than system evolution, ancient fields cannot explain the present magnetization of planets, stars, and galaxies. Instead, self-sustaining dynamos, which convert fluid motion into magnetic energy, offer the most robust explanation. Numerical magnetohydrodynamic simulations are essential to understanding this phenomenon. This thesis uses numerical models of self-excited dynamos in two contexts: the interstellar medium (ISM) and the interiors of gas giant planets. First, I use 3D MHD simulations with the Pencil Code to study magnetic growth from irrotational, subsonic expansion flows, a simplified representation of supernova-driven motions in the ISM. These curl-free flows mimic stellar explosions and winds, drive turbulence, and seed magnetic amplification. The second part examines planetary dynamos. I outline the properties of planetary magnetic fields and their modeling through convection in spherical shells. Although many exoplanets are known, their magnetic fields remain difficult to detect, but may be observable through coherent radio emission with new low-frequency instruments. Using 3D dynamo simulations with the MagIC code, coupled to thermodynamic profiles from MESA-based evolution models, I study the magnetic evolution of cold gas giants. The models show a slow decline in field strength, a shift from multipolar to dipolar states, and clear evolutionary trends in dynamo behavior. I also investigate hot Jupiters, where strong irradiation alters convection and rotation. Most remain fast rotators, but massive, distant planets may enter different regimes. When heating is concentrated in outer layers, convection in the dynamo region weakens, reducing expected field strengths and helping explain the absence of confirmed detections in past radio surveys. + oai:arXiv.org:2512.09725v1 + astro-ph.EP + astro-ph.GA + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Agnieszka Janiuk, Bozena Czerny, Pulkit Ojha, Yuri Cavecchi, Federico Vincentelli + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Albert Elias-L\'opez - Small-scale bright point characteristics at high-resolution with the Daniel K. Inouye Solar Telescope - https://arxiv.org/abs/2512.08520 - arXiv:2512.08520v1 Announce Type: new -Abstract: Bright points (BPs) are small-scale, dynamic features that are ubiquitous across the solar disc and are often associated with the underlying magnetic field. Using broadband photospheric images obtained with the Visible Broadband Imager at the National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST), the properties of BPs have been analyzed with DKIST for the first time at the highest spatial resolutions achievable. BPs were observed to have an average lifetime of 95$\pm$29 s and a mean transverse velocity of 1.60$\pm$0.41 km/s. The BPs had a log-normal area distribution with a peak at 2300 km$^2$. Transverse velocity and lifetimes across the DKIST images were comparable and consistent with previous studies. The area distribution of the DKIST data peaked in areas significantly lower than those from the literature. This was explored further and was observed to be due to an overestimation of BP areas due to the merging of close features when the spatial resolution is reduced, in tandem with possible over-splitting of features in the DKIST images. Furthermore, the effect of variable seeing within the data was determined. This showed that the average spatial resolution of the data was around 0.''034$\pm$0.''007 in comparison to the theoretical diffraction-limit of 0.''022. Accounting for the influence of seeing, the peak of the area distribution of BPs in the DKIST data was estimated as 4800 km$^2$, which is still significantly lower than previously observed. - oai:arXiv.org:2512.08520v1 + Predicting CME Arrivals with Heliospheric Imagers from L5: A Data Assimilation Approach + https://arxiv.org/abs/2512.09738 + arXiv:2512.09738v1 Announce Type: new +Abstract: The Solar TErrestrial RElations Observatory (STEREO) mission has laid a foundation for advancing real-time space weather forecasting by enabling the evaluation of heliospheric imager (HI) data for predicting coronal mass ejection (CME) arrivals at Earth. This study employs the ELEvoHI model to assess how incorporating STEREO/HI data from the Lagrange 5 (L5) perspective can enhance prediction accuracy for CME arrival times and speeds. Our investigation, preparing for the upcoming ESA Vigil mission, explores whether the progressive incorporation of HI data in real-time enhances forecasting accuracy. The role of human tracking variability is evaluated by comparing predictions based on observations by three different scientists, highlighting the influence of manual biases on forecasting outcomes. Furthermore, the study examines the efficacy of deriving CME propagation directions using HI-specific methods versus coronagraph-based techniques, emphasising the trade-offs in prediction accuracy. Our results demonstrate the potential of HI data to significantly improve operational space weather forecasting when integrated with other observational platforms, especially when HI data from beyond 35{\deg} elongation are used. These findings pave the way for optimising real-time prediction methodologies, providing valuable groundwork for the forthcoming Vigil mission and enhancing preparedness for CME-driven space weather events. + oai:arXiv.org:2512.09738v1 astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + physics.space-ph + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Peter H. Keys, Ryan J. Campbell, Dylan K. J. Magill, Mateus A. Keating, Mihalis Mathioudakis, David B. Jess, Damian J. Christian, Arthur Berberyan, Samuel D. T. Grant, Shahin Jafarzadeh, Marco Stangalini, Robertus Erd\'elyi + http://creativecommons.org/licenses/by/4.0/ + Tanja Amerstorfer, Justin Le Lou\"edec, David Barnes, Maike Bauer, Jackie A. Davies, Satabdwa Majumdar, Eva Weiler, Christian M\"ostl - Measuring the diffuse Galactic synchrotron spectral index and curvature between 45 and 2300 MHz - https://arxiv.org/abs/2512.08522 - arXiv:2512.08522v1 Announce Type: new -Abstract: We present an all-sky map of the synchrotron spectral index and curvature between 45 and 2300 MHz at a resolution of 1 degree calculated from a combination of numerous partial sky empirical measurements. We employ a least-squares parametric fit which relies on removing a free-free emission template and a component separation technique which fits for both synchrotron and free-free emission. We compare our diffuse sky model estimates against those derived from the models widely used in the community (e.g. pysm3 and GSM) employing external datasets that were not included in the estimation process. Our evaluation focuses on identifying the enhanced consistency at both the map level and in pixel-to-pixel correlations, allowing for a more robust verification of our model's performance. We find our parametric, least-squares synchrotron estimate to be the most reliable across radio frequencies as it consistently provides sky models with average accuracies (when compared to empirical data) of around 20 per cent, whilst other model performances range on average between 10 and 70 per cent accurate. The results obtained have been made publicly accessible online and can be utilized to further develop and refine models of Galactic synchrotron emission. - oai:arXiv.org:2512.08522v1 - astro-ph.GA + Massive Star Clusters as sources of high-energy gamma radiation + https://arxiv.org/abs/2512.09743 + arXiv:2512.09743v1 Announce Type: new +Abstract: This paper investigates the contribution of massive star clusters (MSC) as sources of high-energy gamma rays and their impact on the ultra-high-energy (UHE) emission observed throughout the Galaxy. By modeling proton injection, the study explores how the acceleration of protons in massive star clusters contributes to the gamma radiation detectable from Earth. The analysis focuses on two primary types of clusters: widespread, dispersed clusters and younger, compact massive clusters, both of which host shock waves generated by supernova remnants (SNR). Clusters located near the solar system, within a 3-kiloparsec radius,are identified. Analytical methods are used to calculate energy spectra and gamma-ray production rates. The findings suggest that young and compact MSC contribute to multi-TeV to PeV gamma-ray emission, with the dominant contribution arising from nearby populations. + oai:arXiv.org:2512.09743v1 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by/4.0/ + Luana N. Padilha, Rita C. Anjos + + + Tachyonic dark energy- Constraints from current observations + https://arxiv.org/abs/2512.09744 + arXiv:2512.09744v1 Announce Type: new +Abstract: Recent observations from the Dark Energy Spectroscopic Instrument (DESI) survey have reignited the debate on the true nature of dark energy, challenging the standard cosmological constant model of cosmology. The results suggest a preference for dark energy to be dynamical rather than a cosmological constant. Several recent analyses of DESI data indicate that the universe's expansion may not be accelerating in the way suggested by supernova based cosmology. Motivated by these studies, we investigated a tachyon type scalar field $\phi$ as a model for dark energy, assuming an exponential potential for the field and performed parameter estimation using Markov Chain Monte Carlo (MCMC) techniques. Such a model offers solutions that have $w \sim -1$ and are decelerating without requiring a phantom like equation of state. The present day value of the equation of state parameter is treated as a free parameter; however, for the reference model, we fix its present value to $-1$. The analysis is carried out using the latest Supernovae dataset (Pantheon+) and BAO measurements from DESI. The results show that both types of datasets consistently predict a turnaround in the equation of state, regardless of whether $w_{\phi 0}$ is treated as a free parameter or fixed to $-1$. The corresponding deceleration parameter also exhibits a future turnaround for both datasets when $w_{\phi 0}$ is free. However, in the reference model with $w_{\phi 0} = -1$, the deceleration parameter instead approaches $-1$ asymptotically. A model comparison using the Akaike and Bayesian Information Criteria shows that the Pantheon+ dataset favors the free $w_{\phi 0}$ scenario, while BAO observations prefer the $w_{\phi 0} = -1$ case. This indicates a disagreement in the future evolution trends predicted by the two datasets within the tachyon type dark energy model. + oai:arXiv.org:2512.09744v1 astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Melis O. Irfan, Giuseppe Puglisi + Ramanpreet Singh, Athul C N, H. K. Jassal - A Search for Transit Duration Variations in M dwarf Multi-Planet Systems - https://arxiv.org/abs/2512.08530 - arXiv:2512.08530v1 Announce Type: new -Abstract: The nominal habitable zone for exoplanets orbiting M dwarfs lies close to the host star, making dynamical considerations especially important. One consequence of this proximity is the expectation of spin synchronization, with implications for atmospheric circulation. Several mechanisms can maintain non-zero obliquities over long timescales in compact multi-planet systems, including capture into Cassini State 2 (CS2) and other forms of secular spin-orbit coupling; such pathways are plausible in the orbital architectures of close-in M-dwarf planets. In this study, we search for transit duration variations (TDVs) consistent with the nodal precession rates predicted by Laplace-Lagrange secular theory in compact M-dwarf multi-planet systems. Our sample includes 23 exoplanets orbiting 12 stars. We compare recent, high-precision transit durations obtained from JWST white-light curves with measurements published at the discovery epoch and afterward. The resulting transit duration variation ranges from seconds to minutes, and we fit a linear trend to duration versus time for each planet. All systems are consistent with flat (no TDV) at the 3{\sigma} level. The strongest candidate is TRAPPIST-1d, whose fitted slope differs from zero with 2.2{\sigma} confidence. We calculate the expected TDV signals predicted by secular precession and compare them to the observed limits. Our null detection is consistent with the low-impact-parameter regime, where theoretical TDVs are only a few seconds per decade and below our sensitivity. Higher-impact-parameter configurations predict substantially larger TDVs and are disfavored: under uniformly distributed geometries, at least half of the allowed configurations would be excluded. - oai:arXiv.org:2512.08530v1 - astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + Euclid preparation. Review of forecast constraints on dark energy and modified gravity + https://arxiv.org/abs/2512.09748 + arXiv:2512.09748v1 Announce Type: new +Abstract: The Euclid mission has been designed to provide, as one of its main deliverables, information on the nature of the gravitational interaction, which determines the expansion of the Universe and the formation of structures. Thus, Euclid has the potential to test deviations from general relativity that will allow us to shed light on long-lasting problems in the standard cosmological model, $\Lambda$CDM. Euclid will mainly do this by using two complementary probes: weak gravitational lensing and galaxy clustering. In this paper we review pre-launch Euclid analyses for dark energy and modified gravity. These include forecast constraints with future Euclid data on cosmological parameters for different cosmological models, such as a time-varying dark energy component, phenomenological modifications of the perturbation sector and specific modified gravity models, with further extensions that include neutrino physics and the coupling to the electromagnetic sector through the fine-structure constant. We review the study of the impact of nonlinear clustering methods on beyond-$\Lambda$CDM constraints with Euclid. This is of fundamental importance to efficiently predict the large-scale clustering of matter and dark matter halos, given that we will have access to a wealth of information on scales beyond the linear regime. We inspect the extension of theoretical predictions for observable quantities in alternative cosmologies to $\Lambda$CDM at fully nonlinear scales by means of $N$-body simulations. We discuss the impact of relativistic corrections in extended cosmological models. Overall, this review highlights the significant potential of the Euclid mission to tightly constrain parameters of dark energy and modified gravity models, or perhaps to detect possible signatures of a $\Lambda$CDM failure. + oai:arXiv.org:2512.09748v1 + astro-ph.CO + gr-qc + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Kohhei Bessho, Sarah Ballard, Natalia Guerrero + Euclid Collaboration, N. Frusciante (Department of Physics "E. Pancini", University Federico II, Via Cinthia 6, 80126, Napoli, Italy), M. Martinelli (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy, INFN-Sezione di Roma, Piazzale Aldo Moro, 2 - c/o Dipartimento di Fisica, Edificio G. Marconi, 00185 Roma, Italy), L. Lombriser (Universit\'e de Gen\`eve, D\'epartement de Physique Th\'eorique and Centre for Astroparticle Physics, 24 quai Ernest-Ansermet, CH-1211 Gen\`eve 4, Switzerland), A. Silvestri (Institute Lorentz, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands), M. Archidiacono (Dipartimento di Fisica "Aldo Pontremoli", Universit\`a degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy, INFN-Sezione di Milano, Via Celoria 16, 20133 Milano, Italy), M. Baldi (Dipartimento di Fisica e Astronomia, Universit\`a di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), M. Ballardini (Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), N. Bartolo (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy, INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), E. Bellini (Center for Astrophysics and Cosmology, University of Nova Gorica, Nova Gorica, Slovenia, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), G. Benevento (INFN, Sezione di Roma 2, Via della Ricerca Scientifica 1, Roma, Italy, Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy), D. Bertacca (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), C. Bonvin (Universit\'e de Gen\`eve, D\'epartement de Physique Th\'eorique and Centre for Astroparticle Physics, 24 quai Ernest-Ansermet, CH-1211 Gen\`eve 4, Switzerland), B. Bose (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), P. Brax (Institut de Physique Th\'eorique, CEA, CNRS, Universit\'e Paris-Saclay 91191 Gif-sur-Yvette Cedex, France, CERN, Theoretical Physics Department, Geneva, Switzerland), V. F. Cardone (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy, INFN-Sezione di Roma, Piazzale Aldo Moro, 2 - c/o Dipartimento di Fisica, Edificio G. Marconi, 00185 Roma, Italy), S. Casas (Institute for Theoretical Particle Physics and Cosmology, Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK), M. Y. Elkhashab (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, Dipartimento di Fisica - Sezione di Astronomia, Universit\`a di Trieste, Via Tiepolo 11, 34131 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), P. G. Ferreira (Department of Physics, Oxford University, Keble Road, Oxford OX1 3RH, UK), F. Finelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), F. Hassani (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), S. Ili\'c (Universit\'e Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France, Institut de Recherche en Astrophysique et Plan\'etologie), K. Koyama (Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK), M. Kunz (Universit\'e de Gen\`eve, D\'epartement de Physique Th\'eorique and Centre for Astroparticle Physics, 24 quai Ernest-Ansermet, CH-1211 Gen\`eve 4, Switzerland), F. Lepori (Department of Astrophysics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland), J. Lesgourgues (Institute for Theoretical Particle Physics and Cosmology), C. J. A. P. Martins (Centro de Astrof\'isica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal), D. F. Mota (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), J. Noller (Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK, Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK), F. Pace (Dipartimento di Fisica, Universit\`a degli Studi di Torino, Via P. Giuria 1, 10125 Torino, Italy, INFN-Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy, INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), D. Paoletti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), G. Parimbelli (Institute of Space Sciences, Dipartimento di Fisica, Universit\`a degli studi di Genova, and INFN-Sezione di Genova, via Dodecaneso 33, 16146, Genova, Italy, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy), V. Pettorino (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands), Z. Sakr (Institut f\"ur Theoretische Physik, University of Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany, Institut de Recherche en Astrophysique et Plan\'etologie, Universit\'e St Joseph, Faculty of Sciences, Beirut, Lebanon), S. Srinivasan (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr.~1, 81679 M\"unchen, Germany), E. M. Teixeira (Laboratoire univers et particules de Montpellier, Universit\'e de Montpellier, CNRS, 34090 Montpellier, France), I. Tutusaus (Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Institut de Recherche en Astrophysique et Plan\'etologie), P. Valageas (Institut de Physique Th\'eorique, CEA, CNRS, Universit\'e Paris-Saclay 91191 Gif-sur-Yvette Cedex, France), H. -A. Winther (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), J. Adamek (Department of Astrophysics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland), I. S. Albuquerque (Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal), L. Atayde (Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal), M. -A. Breton (Institute of Space Sciences, Institut de Ciencies de l'Espai, Laboratoire Univers et Th\'eorie, Observatoire de Paris, Universit\'e PSL, Universit\'e Paris Cit\'e, CNRS, 92190 Meudon, France), S. Camera (Dipartimento di Fisica, Universit\`a degli Studi di Torino, Via P. Giuria 1, 10125 Torino, Italy, INFN-Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy, INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), C. Carbone (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), E. Carella (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), P. Carrilho (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), F. J. Castander (Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya), R. Durrer (Universit\'e de Gen\`eve, D\'epartement de Physique Th\'eorique and Centre for Astroparticle Physics, 24 quai Ernest-Ansermet, CH-1211 Gen\`eve 4, Switzerland), B. Fiorini (Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK), P. Fosalba (Institut d'Estudis Espacials de Catalunya, Institute of Space Sciences), M. Marinucci (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), C. Moretti (SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy), M. Pietroni (Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Universit\`a di Parma, Viale delle Scienze 7/A 43124 Parma, Italy, INFN Gruppo Collegato di Parma, Viale delle Scienze 7/A 43124 Parma, Italy), L. Piga (Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Universit\`a di Parma, Viale delle Scienze 7/A 43124 Parma, Italy, INFN Gruppo Collegato di Parma, Viale delle Scienze 7/A 43124 Parma, Italy, INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), G. R\'acz (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA, Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland), F. Sorrenti (Universit\'e de Gen\`eve, D\'epartement de Physique Th\'eorique and Centre for Astroparticle Physics, 24 quai Ernest-Ansermet, CH-1211 Gen\`eve 4, Switzerland), F. Vernizzi (Institut de Physique Th\'eorique, CEA, CNRS, Universit\'e Paris-Saclay 91191 Gif-sur-Yvette Cedex, France), C. Viglione (Institut d'Estudis Espacials de Catalunya, Institute of Space Sciences), L. Amendola (Institut f\"ur Theoretische Physik, University of Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany), S. Andreon (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), C. Baccigalupi (IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy), S. Bardelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), R. Bender (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany, Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr.~1, 81679 M\"unchen, Germany), A. Biviano (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), D. Bonino (INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), E. Branchini (Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), M. Brescia (Department of Physics "E. Pancini", University Federico II, Via Cinthia 6, 80126, Napoli, Italy, INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy, INFN section of Naples, Via Cinthia 6, 80126, Napoli, Italy), J. Brinchmann (Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal, Faculdade de Ci\^encias da Universidade do Porto, Rua do Campo de Alegre, 4150-007 Porto, Portugal), A. Caillat (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), G. Ca\~nas-Herrera (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands, Institute Lorentz, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands), V. Capobianco (INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), J. Carretero (Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), M. Castellano (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), G. Castignani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Cavuoti (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy, INFN section of Naples, Via Cinthia 6, 80126, Napoli, Italy), K. C. Chambers (Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA), A. Cimatti (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), C. Colodro-Conde (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain), G. Congedo (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), C. J. Conselice (Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK), L. Conversi (European Space Agency/ESRIN, Largo Galileo Galilei 1, 00044 Frascati, Roma, Italy, ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), Y. Copin (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), F. Courbin (Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique F\'ed\'erale de Lausanne, Institut de Ci\`encies del Cosmos, Instituci\'o Catalana de Recerca i Estudis Avan\c{c}ats), H. M. Courtois (UCB Lyon 1, CNRS/IN2P3, IUF, IP2I Lyon, 4 rue Enrico Fermi, 69622 Villeurbanne, France), M. Cropper (Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK), A. Da Silva (Departamento de F\'isica, Faculdade de Ci\^encias, Universidade de Lisboa, Edif\'icio C8, Campo Grande, PT1749-016 Lisboa, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal), H. Degaudenzi (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), G. De Lucia (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), A. M. Di Giorgio (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), J. Dinis (Departamento de F\'isica, Faculdade de Ci\^encias, Universidade de Lisboa, Edif\'icio C8, Campo Grande, PT1749-016 Lisboa, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal), H. Dole (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), F. Dubath (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), X. Dupac (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), S. Dusini (INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), A. Ealet (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), S. Escoffier (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), M. Farina (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), S. Farrens (Universit\'e Paris-Saclay, Universit\'e Paris Cit\'e, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France), F. Faustini (Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy, INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), S. Ferriol (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), S. Fotopoulou (School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK), M. Frailis (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), E. Franceschi (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), M. Fumana (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), S. Galeotta (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), B. Gillis (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), C. Giocoli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Via Irnerio 46, 40126 Bologna, Italy), J. Gracia-Carpio (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), A. Grazian (INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), F. Grupp (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany, Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr.~1, 81679 M\"unchen, Germany), L. Guzzo (Dipartimento di Fisica "Aldo Pontremoli", Universit\`a degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy, INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), S. V. H. Haugan (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), H. Hoekstra (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), W. Holmes (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), I. Hook (Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK), F. Hormuth (Felix Hormuth Engineering, Goethestr. 17, 69181 Leimen, Germany), A. Hornstrup (Technical University of Denmark, Elektrovej 327, 2800 Kgs. Lyngby, Denmark, Cosmic Dawn Center), P. Hudelot (Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, France), K. Jahnke (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), M. Jhabvala (NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA), B. Joachimi (Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK), E. Keih\"anen (Department of Physics and Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), S. Kermiche (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), A. Kiessling (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), B. Kubik (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), H. Kurki-Suonio (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), O. Lahav (Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK), A. M. C. Le Brun (Laboratoire Univers et Th\'eorie, Observatoire de Paris, Universit\'e PSL, Universit\'e Paris Cit\'e, CNRS, 92190 Meudon, France), S. Ligori (INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), P. B. Lilje (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), V. Lindholm (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), I. Lloro (SKAO, Jodrell Bank, Lower Withington, Macclesfield SK11 9FT, UK), G. Mainetti (Centre de Calcul de l'IN2P3/CNRS, 21 avenue Pierre de Coubertin 69627 Villeurbanne Cedex, France), D. Maino (Dipartimento di Fisica "Aldo Pontremoli", Universit\`a degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy, INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy, INFN-Sezione di Milano, Via Celoria 16, 20133 Milano, Italy), E. Maiorano (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), O. Mansutti (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), O. Marggraf (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), K. Markovic (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), N. Martinet (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), F. Marulli (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), R. Massey (Department of Physics, Institute for Computational Cosmology, Durham University, South Road, Durham, DH1 3LE, UK), S. Maurogordato (Universit\'e C\^ote d'Azur, Observatoire de la C\^ote d'Azur, CNRS, Laboratoire Lagrange, Bd de l'Observatoire, CS 34229, 06304 Nice cedex 4, France), E. Medinaceli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Mei (Universit\'e Paris Cit\'e, CNRS, Astroparticule et Cosmologie, 75013 Paris, France), M. Melchior (University of Applied Sciences and Arts of Northwestern Switzerland, School of Engineering, 5210 Windisch, Switzerland), Y. Mellier (Institut d'Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France, Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, France), M. Meneghetti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), E. Merlin (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), G. Meylan (Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique F\'ed\'erale de Lausanne), A. Mora (Aurora Technology for European Space Agency), M. Moresco (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), L. Moscardini (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), C. Neissner (Institut de F\'isica d'Altes Energies, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), R. C. Nichol (School of Mathematics and Physics, University of Surrey, Guildford, Surrey, GU2 7XH, UK), S. -M. Niemi (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands), J. W. Nightingale (School of Mathematics, Statistics and Physics, Newcastle University, Herschel Building, Newcastle-upon-Tyne, NE1 7RU, UK), C. Padilla (Institut de F\'isica d'Altes Energies), S. Paltani (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), F. Pasian (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), K. Pedersen (DARK, Niels Bohr Institute, University of Copenhagen, Jagtvej 155, 2200 Copenhagen, Denmark), W. J. Percival (Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada), S. Pires (Universit\'e Paris-Saclay, Universit\'e Paris Cit\'e, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France), G. Polenta (Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy), M. Poncet (Centre National d'Etudes Spatiales -- Centre spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France), L. A. Popa (Institute of Space Science, Str. Atomistilor, nr. 409 M\u{a}gurele, Ilfov, 077125, Romania), L. Pozzetti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), F. Raison (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), R. Rebolo (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain, Consejo Superior de Investigaciones Cientificas, Calle Serrano 117, 28006 Madrid, Spain), A. Renzi (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), J. Rhodes (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), G. Riccio (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), E. Romelli (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), M. Roncarelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), R. Saglia (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr.~1, 81679 M\"unchen, Germany, Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), A. G. S\'anchez (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), D. Sapone (Departamento de F\'isica, FCFM, Universidad de Chile, Blanco Encalada 2008, Santiago, Chile), B. Sartoris (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr.~1, 81679 M\"unchen, Germany, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), R. Scaramella (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), J. A. Schewtschenko (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), M. Schirmer (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), T. Schrabback (Universit\"at Innsbruck, Institut f\"ur Astro- und Teilchenphysik, Technikerstr. 25/8, 6020 Innsbruck, Austria), A. Secroun (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), E. Sefusatti (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy), G. Seidel (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), M. Seiffert (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), S. Serrano (Institut d'Estudis Espacials de Catalunya, Satlantis, University Science Park, Sede Bld 48940, Leioa-Bilbao, Spain, Institute of Space Sciences), C. Sirignano (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), G. Sirri (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), A. Spurio Mancini (Department of Physics, Royal Holloway, University of London, Surrey TW20 0EX, UK, Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK), L. Stanco (INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), J. Steinwagner (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), P. Tallada-Cresp\'i (Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), D. Tavagnacco (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), A. N. Taylor (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), I. Tereno (Departamento de F\'isica, Faculdade de Ci\^encias, Universidade de Lisboa, Edif\'icio C8, Campo Grande, PT1749-016 Lisboa, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal), N. Tessore (Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK), S. Toft (Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen, Jagtvej 128, 2200 Copenhagen, Denmark), R. Toledo-Moreo (Universidad Polit\'ecnica de Cartagena, Departamento de Electr\'onica y Tecnolog\'ia de Computadoras, Plaza del Hospital 1, 30202 Cartagena, Spain), F. Torradeflot (Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra, Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas), E. A. Valentijn (Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands), L. Valenziano (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), J. Valiviita (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), T. Vassallo (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr.~1, 81679 M\"unchen, Germany, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), G. Verdoes Kleijn (Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands), A. Veropalumbo (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy, Dipartimento di Fisica, Universit\`a degli studi di Genova, and INFN-Sezione di Genova, via Dodecaneso 33, 16146, Genova, Italy), Y. Wang (Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA), J. Weller (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr.~1, 81679 M\"unchen, Germany, Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), A. Zacchei (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), G. Zamorani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), E. Zucca (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), E. Bozzo (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), C. Burigana (INAF, Istituto di Radioastronomia, Via Piero Gobetti 101, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), M. Calabrese (Astronomical Observatory of the Autonomous Region of the Aosta Valley, INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), D. Di Ferdinando (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), J. A. Escartin Vigo (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), G. Fabbian (Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge, CB3 0HA, UK, Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK), M. Maturi (Institut f\"ur Theoretische Physik, University of Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany, Zentrum f\"ur Astronomie, Universit\"at Heidelberg, Philosophenweg 12, 69120 Heidelberg, Germany), N. Mauri (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), A. Pezzotta (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), M. P\"ontinen (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland), C. Porciani (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), V. Scottez (Institut d'Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France, ICL, Junia, Universit\'e Catholique de Lille, LITL, 59000 Lille, France), M. Tenti (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), M. Viel (IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy), M. Wiesmann (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), Y. Akrami (Instituto de F\'isica Te\'orica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain, CERCA/ISO, Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA), V. Allevato (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), S. Anselmi (INFN-Padova, Via Marzolo 8, 35131 Padova, Italy, Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, Laboratoire Univers et Th\'eorie, Observatoire de Paris, Universit\'e PSL, Universit\'e Paris Cit\'e, CNRS, 92190 Meudon, France), F. Atrio-Barandela (Departamento de F\'isica Fundamental. Universidad de Salamanca. Plaza de la Merced s/n. 37008 Salamanca, Spain), A. Balaguera-Antolinez (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), A. Blanchard (Institut de Recherche en Astrophysique et Plan\'etologie), L. Blot (Center for Data-Driven Discovery, Kavli IPMU, Laboratoire Univers et Th\'eorie, Observatoire de Paris, Universit\'e PSL, Universit\'e Paris Cit\'e, CNRS, 92190 Meudon, France), H. B\"ohringer (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany, University Observatory, LMU Faculty of Physics, Scheinerstr.~1, 81679 Munich, Germany, Max-Planck-Institut f\"ur Physik, Boltzmannstr. 8, 85748 Garching, Germany), S. Borgani (Dipartimento di Fisica - Sezione di Astronomia, Universit\`a di Trieste, Via Tiepolo 11, 34131 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy), M. L. Brown (Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK), S. Bruton (California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA), R. Cabanac (Institut de Recherche en Astrophysique et Plan\'etologie), A. Calabro (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), B. Camacho Quevedo (Institut d'Estudis Espacials de Catalunya, Institute of Space Sciences), A. Cappi (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, Universit\'e C\^ote d'Azur, Observatoire de la C\^ote d'Azur, CNRS, Laboratoire Lagrange, Bd de l'Observatoire, CS 34229, 06304 Nice cedex 4, France), F. Caro (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), C. S. Carvalho (Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal), T. Castro (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy), F. Cogato (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Contarini (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), A. R. Cooray (Department of Physics \& Astronomy, University of California Irvine, Irvine CA 92697, USA), S. Davini (INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy), G. Desprez (Department of Astronomy \& Physics and Institute for Computational Astrophysics, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia, B3H 3C3, Canada), A. D\'iaz-S\'anchez (Departamento F\'isica Aplicada, Universidad Polit\'ecnica de Cartagena, Campus Muralla del Mar, 30202 Cartagena, Murcia, Spain), S. Di Domizio (Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy), A. G. Ferrari (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), I. Ferrero (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), A. Finoguenov (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland), F. Fornari (INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), L. Gabarra (Department of Physics, Oxford University, Keble Road, Oxford OX1 3RH, UK), K. Ganga (Universit\'e Paris Cit\'e, CNRS, Astroparticule et Cosmologie, 75013 Paris, France), J. Garc\'ia-Bellido (Instituto de F\'isica Te\'orica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain), T. Gasparetto (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), V. Gautard (CEA Saclay, DFR/IRFU, Service d'Astrophysique, Bat. 709, 91191 Gif-sur-Yvette, France), E. Gaztanaga (Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK), F. Giacomini (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), F. Gianotti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), G. Gozaliasl (Department of Computer Science, Aalto University, PO Box 15400, Espoo, FI-00 076, Finland), A. Gregorio (Dipartimento di Fisica - Sezione di Astronomia, Universit\`a di Trieste, Via Tiepolo 11, 34131 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy), M. Guidi (Dipartimento di Fisica e Astronomia, Universit\`a di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), C. M. Gutierrez (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), A. Hall (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), H. Hildebrandt (Ruhr University Bochum, Faculty of Physics and Astronomy, Astronomical Institute), J. Hjorth (DARK, Niels Bohr Institute, University of Copenhagen, Jagtvej 155, 2200 Copenhagen, Denmark), A. Jimenez Mu\~noz (Univ. Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 53, Avenue des Martyrs, 38000, Grenoble, France), J. J. E. Kajava (Department of Physics and Astronomy, Vesilinnantie 5, University of Turku, 20014 Turku, Finland, Serco for European Space Agency), Y. Kang (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), V. Kansal (ARC Centre of Excellence for Dark Matter Particle Physics, Melbourne, Australia, Centre for Astrophysics \& Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia), D. Karagiannis (School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS, UK, Department of Physics and Astronomy, University of the Western Cape, Bellville, Cape Town, 7535, South Africa), C. C. Kirkpatrick (Department of Physics and Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), S. Kruk (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), F. Lacasa (Universit\'e Libre de Bruxelles, Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), M. Lattanzi (Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), S. Lee (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), J. Le Graet (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), L. Legrand (DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA, UK, Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge, CB3 0HA, UK), M. Lembo (Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), T. I. Liaudat (IRFU, CEA, Universit\'e Paris-Saclay 91191 Gif-sur-Yvette Cedex, France), S. J. Liu (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), A. Loureiro (Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, Stockholm, SE-106 91, Sweden, Astrophysics Group, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK), J. Macias-Perez (Univ. Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 53, Avenue des Martyrs, 38000, Grenoble, France), M. Magliocchetti (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), F. Mannucci (INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Firenze, Italy), R. Maoli (Dipartimento di Fisica, Sapienza Universit\`a di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy, INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), J. Mart\'in-Fleitas (Aurora Technology for European Space Agency), L. Maurin (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), R. B. Metcalf (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), M. Migliaccio (Dipartimento di Fisica, Universit\`a di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, INFN, Sezione di Roma 2, Via della Ricerca Scientifica 1, Roma, Italy), M. Miluzio (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain, HE Space for European Space Agency), P. Monaco (Dipartimento di Fisica - Sezione di Astronomia, Universit\`a di Trieste, Via Tiepolo 11, 34131 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), A. Montoro (Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya), G. Morgante (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Nadathur (Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK), K. Naidoo (Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK), P. Natoli (Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), Nicholas A. Walton (Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK), L. Pagano (Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), K. Paterson (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), L. Patrizii (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), A. Pisani (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France, Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544, USA), V. Popa (Institute of Space Science, Str. Atomistilor, nr. 409 M\u{a}gurele, Ilfov, 077125, Romania), D. Potter (Department of Astrophysics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland), P. Reimberg (Institut d'Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France), I. Risso (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy, and INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy), P. -F. Rocci (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), M. Sahl\'en (Theoretical astrophysics, Department of Physics and Astronomy, Uppsala University, Box 516, 751 37 Uppsala, Sweden), E. Sarpa (SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy), A. Schneider (Department of Astrophysics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland), M. Schultheis (Universit\'e C\^ote d'Azur, Observatoire de la C\^ote d'Azur, CNRS, Laboratoire Lagrange, Bd de l'Observatoire, CS 34229, 06304 Nice cedex 4, France), D. Sciotti (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy, INFN-Sezione di Roma, Piazzale Aldo Moro, 2 - c/o Dipartimento di Fisica, Edificio G. Marconi, 00185 Roma, Italy), M. Sereno (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), L. C. Smith (Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK), K. Tanidis (Department of Physics, Oxford University, Keble Road, Oxford OX1 3RH, UK), C. Tao (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), G. Testera (INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy), R. Teyssier (Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544, USA), S. Tosi (Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy), A. Troja (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), M. Tucci (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), C. Valieri (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), D. Vergani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), G. Verza (Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, NY 10003, USA, Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, 10010, New York, NY, USA), P. Vielzeuf (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France) - NICER Perspective on TeV Blazar Mrk~421: X-ray Variability and Particle Acceleration - https://arxiv.org/abs/2512.08531 - arXiv:2512.08531v1 Announce Type: new -Abstract: Mrk~421 is one of the most fascinating blazars, widely studied across the electromagnetic spectrum using observations at various wavebands, from radio to the TeV gamma ray bands. We present the first detailed spectral and timing analysis of the TeV blazar Mrk~421 based on 45 X-ray observations from the \textit{NICER} X-ray telescope, collected over two years from 2022 to 2024. The source exhibits strong X-ray variability across intraday and long-term timescales. During this period, we observe a dramatic change in flux, from $\sim 50$ to $\sim 1380$~counts~s$^{-1}$, representing a $\sim 28$-fold increase. Spectral modeling with power-law, broken power-law, and log-parabolic functions shows that the log-parabola provides the most accurate description of the X-ray spectra. The hardness ratio analysis confirms a \textit{harder-when-brighter} trend, consistent with the anticorrelation between flux and both $\Gamma$ and $\alpha$. Correlation studies reveal a positive relation between $\alpha$ and $\beta$, a negative correlation between $\beta$ and synchrotron peak energy $E_{\mathrm{p}}$, and a positive correlation between $E_{\mathrm{p}}$ and flux. These observed features can be interpreted within the framework of energy-dependent particle acceleration in blazar jets, which are often associated with turbulence, strong magnetic fields, and relativistic outflows. This work demonstrates that observations from \textit{NICER} can play an important role in blazar variability studies and motivate future multiwavelength campaigns aimed at fully characterizing the dynamical processes in relativistic jets. - oai:arXiv.org:2512.08531v1 + Origin of the stellar Fe K{\alpha} line clarified with FUV and X-ray observations of a superflare on the RS Canum Venaticorum-type Star UX Arietis + https://arxiv.org/abs/2512.09750 + arXiv:2512.09750v1 Announce Type: new +Abstract: Fluorescence line diagnostics of the Fe K{\alpha} line at $\sim 6.4$ keV observed in both solar and stellar flares can constrain the latitude and size of the flare loop, even in the absence of imaging observations. However, they are hampered by the unresolved origin of stellar Fe K{\alpha} lines: i.e., it is unclear which of the two mechanisms-photoionization by hard X-ray photons or collisional ionization by non-thermal electrons-is the dominant process. We present clear evidence for the photoionization origin based on simultaneous far ultraviolet (FUV) and soft X-ray observations of a superflare on the RS Canum Venaticorum-type Star UX Arietis with Extreme ultraviolet spetrosCope for ExosphEric Dynamic (EXCEED; 900$-$1480 \r{A}) onboard Hisaki and Neutron Star Interior Composition Explorer (NICER; 0.2$-$12 keV). The flare started at 22:50 UT on 2018 November 15 and released $2 \times 10^{36}$ erg in the 900$-$1480 \r{A} band and $3 \times 10^{36}$ erg in the 0.3$-$4 keV band. The FUV emission, a proxy for non-thermal activity, peaked approximately 1.4 hours before the soft X-rays. In contrast, the Fe K{\alpha} line, detected at a statistical significance of $5.3 \sigma$ with an equivalent width of $67^{+28}_{-20}$ eV, peaked simultaneously with the thermal X-ray maximum rather than the non-thermal FUV peak-strongly supporting the photoionization hypothesis. Radiative transfer calculations, combined with the observed Fe K{\alpha} line intensity, further support the photoionization scenario and demonstrate the potential of this line to provide the flare geometry. + oai:arXiv.org:2512.09750v1 + astro-ph.SR astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Sangeetha Kizhakkekalam, Gopal Bhatta, Navaneeth P K, Tek P. Adhikari + Shun Inoue, Wataru Buz Iwakiri, Tomoki Kimura, Teruaki Enoto, Yuta Notsu, Hiroyuki Uchida, Kenji Hamaguchi, Shin Toriumi, Atsushi Yamazaki, Fuminori Tsuchiya, Go Murakami, Kazuo Yoshioka, Zaven Arzoumanian, Keith Gendreau - Astrometric Reconnaissance of Exoplanetary Systems (ARES). I. Methodology validation with HST point-source images of Proxima Centauri - https://arxiv.org/abs/2512.08533 - arXiv:2512.08533v1 Announce Type: new -Abstract: We present the first results of the Astrometric Reconnaissance of Exoplanetary Systems (ARES) project, aimed at validating and characterizing candidate exoplanets around the nearest systems using multi-epoch Hubble Space Telescope (HST) data. In this first paper, we focus on Proxima Centauri, leveraging archival and recent HST observations in point-source imaging mode. We refine the geometric-distortion calibration of the HST detector used, and develop a robust methodology to derive high-precision astrometric parameters by combining HST measurements with the Gaia DR3 catalog. We determine Proxima's position, proper motion, and parallax with uncertainties at the $\sim$0.4-mas, 50-$\mu$as yr$^{-1}$, and 0.2-mas level, respectively, achieving consistent results with what measured by Gaia within $\sim$1$\sigma$. We further investigate the presence of the candidate exoplanet Proxima c by analyzing the proper-motion anomaly derived from combining long-term HST-based and short-term Gaia astrometry. Under the assumption of a circular, face-on orbit, we obtain an estimated mass of $m_c = 3.4^{+5.2}_{-3.4}$ $M_\odot$, broadly consistent with radial-velocity constraints but limited by our current uncertainties. These results establish the foundation for the next phase of ARES, which will exploit HST spatial-scanning observations to achieve astrometric precisions of a few tens of $\mu$as and enable a direct search for astrometric signatures of low-mass companions. - oai:arXiv.org:2512.08533v1 - astro-ph.EP - astro-ph.IM - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Adding electromagnetic birefringence to pulsar timing and astrometry to detect gravitational waves + https://arxiv.org/abs/2512.09759 + arXiv:2512.09759v1 Announce Type: new +Abstract: It was recently shown that the time variation of the polarization of electromagnetic waves from pulsars can be used, in cross-correlation with pulsar timing, to probe the chirality of an isotropic gravitational wave background. Here, we show that the expression for the cross-correlation is derived efficiently with the total-angular-momentum formalism and use this framework to extend the formulation to cross-correlation with astrometry. We do so for spin-1 gravitational waves (that may arise in alternative-gravity theories) as well as the general-relativistic spin-2 gravitational waves. + oai:arXiv.org:2512.09759v1 + astro-ph.CO + gr-qc + hep-ph + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - M. Libralato, L. Bedin, A. Burgasser + Keisuke Inomata, Marc Kamionkowski - High-Redshift Galactic Outflows: Orientation Effects, Kinematics, and Metallicity in TNG50 and SERRA - https://arxiv.org/abs/2512.08543 - arXiv:2512.08543v1 Announce Type: new -Abstract: Context: Recently, JWST/NIRSpec observations have provided the first detections of warm ionised outflows in low-mass galaxies at high redshifts (z>3), revealing an occurrence rate of 25-40% depending on the intensity of the emission lines. This fraction is lower than predicted by simulations, which suggest that fast outflowing gas should be a common feature of all star-forming galaxies in the early Universe. Aims: In order to better understand the discrepancies between simulations and observations, we identify and characterize outflows in high-redshift galaxies using the TNG50 cosmological and SERRA zoom-in simulations. Our study examines how outflow detectability depends on the line of sight, explores the properties of the fast gas, and investigates its relationship with key galactic properties. Methods: We analyse approximately 60000 galaxies from TNG50 and 3000 galaxies from SERRA over the redshift ranges z=3-5 and z=4-5, respectively, spanning stellar masses of Mstar=10^7.5-10^11Msun. Outflows in the immediate vicinity of each galaxy are identified using a Gaussian mixture model algorithm that uses the gas velocity, star-formation-rate, and location as input parameters. We subsequently compare the simulated outflows to those observed in the JWST/JADES NIRSpec survey. Results: Outflow masses in both TNG50 and SERRA broadly reproduce the JWST/JADES measurements within roughly 0.5dex, though simulations tend to predict slightly higher values, suggesting that optical emission lines capture only a fraction of the multiphase outflow. However, simulated outflow velocities are typically an order of magnitude lower than those inferred from observations. TNG50 indicates a clear orientation dependence as outflows in face-on galaxies are approximately 15% more likely to be detected than in edge-on systems, with this difference increasing to nearly 40% for more massive, disc-shaped galaxies. - oai:arXiv.org:2512.08543v1 + Revisiting the X-ray-to-UV relation of Quasars in the era of all-sky surveys + https://arxiv.org/abs/2512.09767 + arXiv:2512.09767v1 Announce Type: new +Abstract: The X-ray--to--UV relation of active galactic nuclei (AGNs), commonly parametrized via the monochromatic luminosities at $2500\,\mathring{A}$ and $2\,keV$, reflects the energetic interplay between the accretion disc and the X-ray-emitting corona, and is key for understanding accretion physics. Previous studies suggest that disc-dominated emission becomes more prominent with increasing optical luminosity. However, the redshift evolution of this relation remains debated, and a dependence on Eddington ratio, predicted by accretion flow models, is still observationally unconstrained. We revisit this relation using a large, nearly all-sky sample by combining the SDSS DR16Q QSO catalogue with X-ray data from XMM-Newton and the SRG/eROSITA All-Sky Survey DR1, yielding 136,745 QSOs at redshifts $0.5 \leq z < 3.0$. We introduce a hierarchical Bayesian framework that treats X-ray detections and upper limits uniformly, enabling robust inference from both parametric and non-parametric models. We confirm a tight, sublinear $\log L_X({\rm 2\,keV})$-$\log L_{\nu}({\rm 2500\,\mathring{A}})$ correlation, but with a normalization at the lower end of previous estimates. Contrary to most literature results, we detect a mild but systematic redshift evolution: the relation flattens and its intrinsic scatter decreases at higher redshift. This trend is consistent with disc emission increasingly dominated by scattering and enhanced energy transfer to the X-ray corona, potentially indicating redshift evolution in the X-ray bolometric correction. We find no significant dependence on Eddington ratio, in tension with recent accretion flow models. + oai:arXiv.org:2512.09767v1 astro-ph.GA - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Ivan Kostyuk, Stefano Carniani, Mahsa Kohandel, Andrea Pallottini + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + 10.1093/mnras/staf1905 + Maria Chira, Antonis Georgakakis, Angel Ruiz, Shi-Jiang Chen, Johannes Buchner, Amy L. Rankine, Elias Kammoun, Catarina Aydar, Mara Salvato, Andrea Merloni, Mirko Krumpe - The Two-Dimensional Structure of Circumplanetary Disks and their Radiative Signatures - https://arxiv.org/abs/2512.08610 - arXiv:2512.08610v1 Announce Type: new -Abstract: During their formative stages, giant planets are fed by infalling material sourced from the background circumstellar disk. Due to conservation of angular momentum, the incoming gas and dust collects into a circumplanetary disk that processes the material before it reaches the central planet itself. This work investigates the complex vertical structure of these circumplanetary disks and calculates their radiative signatures. A self-consistent numerical model of the temperature and density structure of the circumplanetary environment reveals that circumplanetary disks are thick and hot, with aspect ratios $H/R\sim0.1-0.25$ and temperatures approaching that of the central planet. The disk geometry has a significant impact on the radiative signatures, allowing future observations to determine critical system parameters. The resulting disks are gravitationally stable and viscosity is sufficient to drive the necessary disk accretion. However, sufficiently rapid mass accretion can trigger a thermal instability, which sets an upper limit on the mass accretion rate. This paper shows how the radiative signatures depend on the properties of the planetary system and discuss how the system parameters can be constrained by future observations. - oai:arXiv.org:2512.08610v1 + Water versus land on temperate rocky planets + https://arxiv.org/abs/2512.09785 + arXiv:2512.09785v1 Announce Type: new +Abstract: Water and land surfaces on a planet interact with gases in the atmosphere and with radiation from the star. These interactions define the environments that prevail on the planet, some of which may be more amenable to prebiotic chemistry, some to the evolution of more complex life. This review article covers (i) the physical conditions that determine the ratio of land to sea on a rocky planet, (ii) how this ratio would affect climatic and biologic processes, and (iii) whether future astronomical observations might constrain this ratio on exoplanets. Water can be delivered in multiple ways to a growing rocky planet -- and although we may not agree on the contribution of different mechanism(s) to Earth's bulk water, hydrated building blocks and nebular ingassing could at least in principle supply several oceans' worth. The water that planets sequester over eons in their solid deep mantles is limited by the water concentration at water saturation of nominally anhydrous mantle minerals, likely less than 2000 ppm of the planet mass. Water is cycled between mantle and surface through outgassing and ingassing mechanisms that, while tightly linked to tectonics, do not necessarily require plate tectonics in every case. The actual water/land ratio at a given time emerges from the balance between the volume of surface water on the one hand, and on the other hand, the shape of the planet (its ocean basin volume) that is carved out by dynamic topography, the petrologic evolution of continents, impact cratering, and other surface-sculpting processes. By leveraging the contrast in reflectance properties of water and land surfaces, spatially resolved 2D maps of Earth-as-an-exoplanet have been retrieved from models using real Earth observations, demonstrating that water/land ratios of rocky exoplanets may be determined from data delivered by large-aperture, high-contrast imaging telescopes in the future. + oai:arXiv.org:2512.09785v1 astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Aster G. Taylor, Fred C. Adams, Nuria Calvet + Claire Marie Guimond, Tilman Spohn, Svetlana Berdyugina, Paul K. Byrne, Nicolas Coltice, Donald M. Glaser, Manasvi Lingam, Charles H. Lineweaver, Peter A. Cawood - HI-detected Dwarf Galaxies in the FASHI Survey: Insights from Single- and Double-Peaked Emission-Line Samples - https://arxiv.org/abs/2512.08644 - arXiv:2512.08644v1 Announce Type: new -Abstract: We present a sample of low HI mass dwarf galaxies ($M_{\rm HI} < 10^8 M_\odot$) detected by The FAST All Sky HI Survey (FASHI) project. Due to the faint and irregular morphology of these galaxies, the default photometry is often inaccurate. Therefore, we utilized The Dark Energy Camera Legacy Survey (DECaLS) data to perform careful photometric measurements, and find that the low HI mass galaxies have similar stellar mass densities to dwarf elliptical (dE) galaxies. Compared to other dwarf galaxy populations, the HI-selected dwarfs exhibit higher stellar mass densities than ultradiffuse galaxies, and similar densities to HI-selected low-surface-brightness galaxies, albeit with lower stellar masses, suggesting a possible evolutionary connection among these populations. By classifying the galaxies according to their HI spectral-line profiles, we show that the double-peaked sources conform closely to the Tully-Fisher relation, whereas the single-peaked sources follow the Faber-Jackson relation but with large scatter. This indicates that the single-peaked systems are likely dispersion dominated and that the relationship between stellar mass and halo mass in such systems may remain consistent across both low- and high-mass regimes. These findings suggest that HI-selected dwarf galaxies with single-peaked HI profiles may share a similar dynamical state with massive ellipticals, offering new insights into their structural evolution and the diversity of formation pathways for low-mass galaxies. - oai:arXiv.org:2512.08644v1 + Kinematics of Distant Milky Way Halo RR Lyrae Stars out to 160 kpc + https://arxiv.org/abs/2512.09795 + arXiv:2512.09795v1 Announce Type: new +Abstract: We present a kinematical study of the outer halo (r_GC approximately 60 to 160 kpc) of the Milky Way based on spectroscopy of 55 RR Lyrae stars obtained with the ESI instrument on the Keck II telescope. Our spectroscopic targets were selected from three photometric surveys: NGVS, DES, and Pan-STARRS1. We derive center-of-mass radial velocities with uncertainties of 6 to 35 km s^-1. The halo velocity dispersion measured from our sample is 70 plus/minus 7 km s^-1. The velocity field shows a possible dipole-like structure, with redshifted northern and blueshifted southern hemispheres. Fitting a Milky Way - Large Magellanic Cloud dipole perturbation model yields a weak or marginal dipole signal with amplitude -30 (+16, -20) km s^-1 and apex direction (l, b) = (-38.2 (+42.4, -31.5), -41.3 (+27.9, -23.8)) deg, along with a bulk compression velocity of -16 plus/minus 11 km s^-1. Although limited by sky coverage and sample size, our results are consistent with the presence of LMC-induced disequilibrium in the distant halo beyond 100 kpc. In addition to the 55 RR Lyrae stars, our spectroscopy reveals that 10 additional photometrically selected RR Lyrae candidates are actually quasar or blazar contaminants, highlighting the need for caution regarding such contaminants in sparsely sampled photometric surveys. Our study demonstrates that single-epoch spectroscopy of RR Lyrae stars is a viable method for probing the kinematics of the outer halo, and future surveys such as Rubin LSST and DESI-II have the potential to significantly advance this effort. + oai:arXiv.org:2512.09795v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Cheng Cheng, Jia-Sheng Huang, Wei Du, Hong-Xin Zhang, Chuan-Peng Zhang, Ming Zhu, Gustavo Orellana + http://creativecommons.org/licenses/by/4.0/ + Yuting Feng, Puragra Guhathakurta, Eric W. Peng, Emily C. Cunningham, Patrick C\^ot\'e, Laura Ferrarese, Stephen D. J. Gwyn - Predicting Quasar Counts Detectable in the LSST Survey - https://arxiv.org/abs/2512.08654 - arXiv:2512.08654v1 Announce Type: new -Abstract: The Legacy Survey of Space and Time (LSST), being conducted by the Vera C. Rubin Observatory, is a wide-field multi-band survey that will revolutionize our understanding of extragalactic sources through its unprecedented combination of area and depth. While the LSST survey strategy is still being finalized, the Rubin Observatory team has generated a series of survey simulations using the LSST Operations Simulator to explore the optimal survey strategy that best accommodates the majority of scientific goals. In this study, we utilize the latest simulated data to predict the number of detectable quasars by LSST in each band and evaluate the impact of different survey strategies. We find that the number of quasars and lower luminosity AGNs detected in the baseline strategy (v4.3.1) in the redshift range z=0.3-6.7 will be highest in the i-band and lowest in the u-band. Over 70% of quasars are expected to be detected within the first year in all bands, as LSST will have already reached the break of the luminosity function at most redshifts. With a limiting magnitude of 25.7 mag, we expect to detect 184 million AGNs in the z-band over the 10-year survey, with quasars constituting only 6% of the total AGNs in each band. This arises because, considering that the luminosities of most low-luminosity AGNs are affected by contamination from their host galaxies, we set a magnitude threshold when predicting the number of quasars. We find that variations in the u-band strategy can impact the number of quasar detections. Specifically, the difference between the baseline strategy and that with the largest total exposure in u is 15%. In contrast, changes in rolling strategies, DDF strategies, weather conditions, and Target of Opportunity observations result in variations below 2%. These results provide valuable insights for optimizing approaches to maximize the scientific output of quasar studies. - oai:arXiv.org:2512.08654v1 + Footprints in the Wind: Probing X-ray Outflows in NGC 7469 using Near-Infrared Emission Lines + https://arxiv.org/abs/2512.09815 + arXiv:2512.09815v1 Announce Type: new +Abstract: AGN winds play an important role in the co-evolution of supermassive black holes and their host galaxies, yet their driving mechanisms and impact on star formation remain subjects of active investigation. Critically, the lack of X-ray Integral Field Units currently limits our ability to acquire spatially resolved velocity information in the X-ray regime. However, instead, this can be achieved using the James Webb Space Telescope. As part of an ongoing investigation of the nuclear feedback processes in the nearby luminous AGN NGC 7469, we present an analysis of the kinematics of the X-ray emitting outflows using near-infrared footprint lines such as [Mg VIII] 3.03 um. These high-ionization emission lines are associated with the same gas analyzed in the X-ray, and thus can be used to probe the footprint of the X-ray wind's velocity structure and ionization state. Thanks to the wide wavelength range available with JWST we also use nebular (e.g. [S IV] 10.51 um) and coronal (e.g. [Ne V] 14.32 um) emission lines to offer a comprehensive multi-phase view of the outflows. We present mass and kinetic energy outflow rates, and find that while the feedback processes in NGC 7469 are not efficient by theoretical benchmarks, the most massive and energetic component is the high ionization X-ray gas. + oai:arXiv.org:2512.09815v1 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Guodong Li, Roberto J. Assef, W. N. Brandt, Matthew J. Temple, Franz E. Bauer, Marcin Marculewicz, Swayamtrupta Panda, Alessandro Peca, Claudio Ricci, Gordon T. Richards, Sarath Satheesh Sheeba, Chao-Wei Tsai, Jingwen Wu, Ilsang Yoon + L\'ea M. Feuillet, Steve Kraemer, Anna Trindade Falc\~ao, Valentina Braito, Marcio Mel\'endez, Henrique R. Schmitt, James N. Reeves, Riccardo Middei, Travis C. Fischer, Mitchell Revalski - Pulsars identified in the LOFAR Two-metre Sky Survey at 144 MHz - https://arxiv.org/abs/2512.08663 - arXiv:2512.08663v1 Announce Type: new -Abstract: We present the astrometric identification of 80 known radio pulsars as unresolved continuum sources detected at 144 MHz in the second data release of the LOFAR Two-metre Sky Survey (LoTSS DR2), which covers 27% of the Northern hemisphere. These identifications represent the majority ($\geq$ 86%) of radio pulsars present in the LoTSS DR2 footprint and provide independent celestial positions and flux densities at 144 MHz. We compare LoTSS flux densities with literature values from various image and time-domain observations and find good agreement for all but two pulsars. We attribute these flux density deviations to intrinsic pulsar properties (nulling and off-pulse emission). We investigate criteria to select promising pulsar candidates using data from the upcoming LoTSS release of the entire Northern sky ($\delta>0^\circ$), as well as the LOFAR LBA Sky Survey (LoLSS) at 54 MHz (covering $\delta>24^\circ$). Of the 80 detections, 35 (44%) were blindly redetected based on their linear or circular polarization. Therefore we conclude that candidate selection based on polarization properties is a promising approach. Candidate selection can be supplemented with spectral indices via cross-matching to LoLSS sources at 54 MHz, as the high sensitivity of LoTSS is not matched by image-domain surveys at higher frequencies. - oai:arXiv.org:2512.08663v1 - astro-ph.HE - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + The Oxygen Valve on Hydrogen Escape Since the Great Oxidation Event + https://arxiv.org/abs/2512.09844 + arXiv:2512.09844v1 Announce Type: new +Abstract: The Great Oxidation Event (GOE) was a $200$ Myr transition circa 2.4 billion years ago that converted the Earth's anoxic atmosphere to one where molecular oxygen (O$_2$) was abundant (volume mixing ratio $>10^{-4}$). This significant rise in O$_2$ is thought to have substantially throttled hydrogen (H) escape and the associated water (H$_2$O) loss. Atmospheric estimations from the GOE onward place O$_2$ concentrations ranging between 0.1\% to 150\% PAL, where PAL is the present atmospheric level of 21% by volume. In this study we use WACCM6, a three-dimensional Earth System Model to simulate Earth's atmosphere and predict the diffusion-limited escape rate of hydrogen due to varying O$_2$ post-GOE. We find that O$_2$ indirectly acts as a control valve on the amount of hydrogen atoms reaching the homopause in the simulations: less O$_2$ leads to decreased O$_3$ densities, reducing local tropical tropopause temperatures by up to 18 K, which increases H$_2$O freeze-drying and thus reduces the primary source of hydrogen in the considered scenarios. The maximum differences between all simulations in the total H mixing ratio at the homopause and the associated diffusion-limited escape rates are a factor of 3.2 and 4.7, respectively. The prescribed CH$_4$ mixing ratio (0.8 ppmv) sets a minimum diffusion escape rate of $\approx 2 \times 10^{10}$ mol H yr$^{-1}$, effectively a negligible rate when compared to pre-GOE estimates ($\sim 10^{12}-10^{13}$ mol H y$^{-1}$). Because the changes in our predicted escape rates are comparatively minor, our numerical predictions support geological evidence that the majority of Earth's hydrogen escape occurred prior to the GOE. Our work demonstrates that estimations of how the hydrogen escape rate evolved through Earth's history requires 3D chemistry-climate models which include a global treatment of water vapour microphysics. + oai:arXiv.org:2512.09844v1 + astro-ph.EP + physics.geo-ph + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - G. A. C. Rijkers, C. G. Bassa, J. R. Callingham, T. Shimwell + Gregory J. Cooke, Dan R. Marsh, Catherine Walsh, Felix Sainsbury-Martinez, Marrick Braam - Stochastic gravitational-wave background search using data from five pulsar timing arrays - https://arxiv.org/abs/2512.08666 - arXiv:2512.08666v1 Announce Type: new -Abstract: Using public data from five pulsar timing arrays (PTAs), we search for a stationary, isotropic, and unpolarized nHz stochastic gravitational-wave background (SGWB). We use pulse time-of-arrival data from 121 pulsars, which is more informative than previous searches, carried out separately by the individual PTA collaborations using only their own data. For pulsars observed by more than one PTA, we employ a new "direct combination" method to merge their astrophysical models and data. This avoids the challenge of reconciling the different PTA timing models to obtain a single "best" model. A central result of our analysis is posterior probability distributions for the amplitude $A_{gw}$ and exponent $\gamma_{gw}$ of the putative SGWB energy-density spectrum, modeled as a power law in frequency. While these results are consistent with a nonzero SGWB amplitude $A_{gw}$, the statistical significance--assessed via a Bayesian odds ratio and through noise-marginalized false-alarm probabilities ($p$-values) for three different detection statistics--remains below the conventional $5\sigma$ threshold for a confident detection. We also reconstruct the inter-pulsar timing-residual correlation as a function of the angle $\theta$ between the pulsar lines of sight. This is consistent with the curve predicted by Hellings and Downs (HD). - oai:arXiv.org:2512.08666v1 + Primordial non-Gaussianity -- Fast simulations and persistent summary statistics + https://arxiv.org/abs/2512.09852 + arXiv:2512.09852v1 Announce Type: new +Abstract: We investigate the sensitivity of topological and traditional summary statistics to primordial non-Gaussianity (PNG) using two suites of simulations. First, we introduce a new simulation suite for PNG, PNG-pmwd, comprising more than $20{,}000$ halo catalogs that vary individually local and equilateral shapes, together with variations in $\Omega_m$ and $\sigma_8$. Second, we carry out a systematic comparison of topological descriptors, as well as powerspectrum and bispectrum measurements, evaluating their constraining power on both local and equilateral $f_{\rm NL}$ and how this sensitivity varies with halo mass. This dataset enables likelihood-free neural regression of $f_{\rm NL}$ across multiple halo mass bins for a wide range of summary statistics. Third, we assess the transferability of these learned mappings by testing whether models trained on fast pmwd simulations can robustly infer on simulations from the QuijotePNG suite. We find that a combination of simple descriptive statistics of the topological features (PD-statistics) leads to the best performance to constrain equilateral PNG. We observe that the constraining power of these summaries comes from large-mass halos, with small-mass halos adding noise and degrading performance. Similarly, we find that the transferability of the learned mappings, for both topological and powerspectrum plus bispectrum, degrades if small scales or small-mass halos are included. + oai:arXiv.org:2512.09852v1 astro-ph.CO - gr-qc - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Wang-Wei Yu, Bruce Allen + Juan Calles, Gabriella Contardo, Jorge Nore\~na, Jacky H. T. Yip, Gary Shiu - Low-Mass Neutron Stars and Effective Phase Transitions from a Hybrid Van der Waals-Polytropic Equation of State - https://arxiv.org/abs/2512.08672 - arXiv:2512.08672v1 Announce Type: new -Abstract: We study phase-transition-like behavior in neutron stars using a simplified, piecewise equation of state that couples a modified van der Waals-type core to a polytropic crust. The model remains analytically tractable while allowing for nonlinear density dependence. We impose thermodynamic and causal consistency conditions and determine the critical densities at which the curvature of the pressure-energy density relation changes. In the non-relativistic limit, the generalized Lane-Emden equations describe a smooth core-crust transition layer. We integrate the Tolman-Oppenheimer-Volkoff equations across different $(\tau_1,\sigma_1)$ regimes, where these parameters encode thermal and interaction effects in the core. The resulting mass-radius sequences yield low neutron star masses $(0.99-2.05)M_{\odot}$, and the chemical potential exhibits the characteristic signatures of phase-transition behavior at densities well above the matching point. Our results show that analytic EOS models can reproduce the key phenomenology of phase transitions and provide a controlled framework for exploring low-mass neutron star configurations. - oai:arXiv.org:2512.08672v1 - astro-ph.HE + The Limits of Line Broadening: Modeling Stellar Spectra and Formation Temperatures at High Resolution + https://arxiv.org/abs/2512.09861 + arXiv:2512.09861v1 Announce Type: new +Abstract: The modeling of stellar spectra is pervasive in astronomy. Conventionally, the shapes of absorption lines are modeled by convolving thermal profiles (computed given some model stellar atmosphere and line list) with broadening kernels intended to account for the effects of rotation and other nonthermal sources of broadening (i.e., macroturbulence). Here, we show that the assumptions that permit this convolution can break down at high spectral resolution and produce appreciable errors in the modeled flux. We then consider the effects of rotation, microturbulence, and macroturbulence on the intensity and flux contribution functions, which astronomers use to map individual spectral segments to quasi-physical formation ``locations'' in the stellar atmosphere. We show that proper consideration of 1) the distinction between intensity and flux and 2) the inclusion of rotation and macroturbulence in the contribution function can dramatically change the modeled formation temperatures. To complement this analysis, we provide a package -- FormationTemperatures.jl -- which quickly computes model line contribution functions and formation parameters given bulk stellar properties as input. In closing, we emphasize the assumptions inherent to this analysis, consider in which regimes the convolution expression for flux should be avoided, and caution how the concept of a singular ``formation temperature'' can oversimplify some realities of radiative transfer. + oai:arXiv.org:2512.09861v1 astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - P. H. F. Arruda, S. D. Campos + Michael L. Palumbo III - A magnetar outburst with atypical evolution: the case of Swift J1555.2-5402 - https://arxiv.org/abs/2512.08692 - arXiv:2512.08692v1 Announce Type: new -Abstract: The magnetar Swift J1555.2-5402 was discovered in outburst on 2021 June 3 by the Burst Alert Telescope on board the Swift satellite. Early X-ray follow-up revealed a spin period P~3.86 s, a period derivative Pdot~3e-11 s/s, dozens of short bursts, and an unusually flux decline. We report here on the X-ray monitoring of Swift J1555.2-5402 over the first ~29 months of its outburst with Swift, NICER, NuSTAR, INTEGRAL and Insight-HXMT, as well as radio observations with Parkes soon after the outburst onset. The observed 0.3-10 keV flux remained at levels >~1e-11 erg/cm^2/s for nearly 500 days before dropping by a factor of ~10 from its June 2021 peak towards the end of the monitoring campaign. During this time span, the spectrum was dominated by a single blackbody, with temperature attaining approximately a constant value (~1.2 keV) while the inferred radius shrank from ~1.7 km to ~0.3 km (assuming a source distance of 10 kpc). The long-term spin-down rate (Pdot~3.6e-11 s/s) is only ~15 % higher than that measured in the first 30 days. No periodic or burst-like radio emission was detected, in line with what has been previously reported using different radio facilities. The persistently high temperature, shrinking hotspot, and a prolonged bright flux plateau followed by a fast dimming observed during the outburst evolution pose a challenge for the outburst mechanisms proposed so far. - oai:arXiv.org:2512.08692v1 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - A. Borghese, F. Coti Zelati, M. Imbrogno, G. L. Israel, D. De Grandis, D. P. Pacholski, M. Trudu, M. Burgay, S. Mereghetti, N. Rea, P. Esposito, M. Pilia, A. Possenti, R. Turolla, L. Ducci - - - The frame-dragging vector potential on galaxy scales from DM-only Newtonian $N$-body simulations - https://arxiv.org/abs/2512.08703 - arXiv:2512.08703v1 Announce Type: new -Abstract: Effects of General Relativity are usually neglected in the non-linear evolution of structures, where Newtonian $N$-body simulations are traditionally employed. In the post-Friedmann expansion framework, a weak-field relativistic approximation purpose-built for cosmology, a frame-dragging gravito-magnetic vector potential arises at leading order, sourced by momentum currents, contributing to the metric even if the dynamics of matter fields at this order is Newtonian, and can thus be extracted from $N$-body simulations. Using the Delaunay Tessellation Field Estimator code on the IllustrisTNG simulations, here we extend previous work in order to compute the power spectrum of this vector potential down to galactic scales. The magnitude of the vector potential is two orders of magnitude larger than predicted by perturbation theory, and is a $1\% \sim 0.1\%$ effect compared to the non-linear Newtonian scalar gravitational potential. In the red-shift range considered here, the gravito-magnetic effect remains subdominant, without showing any enhancement during a particular phase in the evolution of structures, aside from the continuous growth of non-linearity at low redshift. Although this seems to suggest that, within the $\Lambda$CDM model, no significant gravito-magnetic effects contribute to the non-linear evolution of cosmic structures, i.e. to the dynamics of massive particles, possible observational consequences, e.g. in lensing, deserve further exploration. - oai:arXiv.org:2512.08703v1 - astro-ph.CO - astro-ph.GA - gr-qc - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - William Beordo, Marco Bruni, Cristian Barrera-Hinojosa, Mariateresa Crosta - - - Thermal design of focal plane assembly of wavefront camera for exoplanet imaging corona module - https://arxiv.org/abs/2512.08708 - arXiv:2512.08708v1 Announce Type: new -Abstract: The focal plane assembly of wavefront camera is the key imaging device of wavefront detection camera and the key load of the exoplanet imaging coronagraph module. In order to ensure the imaging quality and reduce the dark current and thermal noise, it is necessary to effectively dissipate the heat of the focal plane CCD and other high-power electronic devices to ensure the working performance and reliability of the focal plane assembly. Based on the limited space and cooling resources, this paper adopts the flexible graphene heat conducting cable and grooved heat pipes, and carries out detailed thermal design and thermal analysis of its cooling path. The finite element model is established by thermal analysis software and thermal simulation is carried out. in that steady state, the work temperature range of the CCD chip is -12.8 to -10.9 celsius, which meets the temperature control index, and the work temperatures of other components are also within the design requirements, which indicate that the thermal design scheme is reasonable and feasible, and meets the task requirements. - oai:arXiv.org:2512.08708v1 - astro-ph.IM - Wed, 10 Dec 2025 00:00:00 -0500 + Beyond Two Parameters: Revisiting Dark Energy with the Latest Cosmic Probes + https://arxiv.org/abs/2512.09866 + arXiv:2512.09866v1 Announce Type: new +Abstract: Dark energy (DE) models with many free parameters are often considered excessive, as constraining all parameters poses a significant challenge. On the other hand, such models offer greater flexibility to probe the DE sector in more detail. With the rapid advancement of astronomical surveys and the availability of diverse datasets, it is timely to examine whether current combined observations can effectively constrain an extended parameter space in DE models. This article investigates a four-parameter dynamical dark energy (DDE) model that spans a broad region of the universe's expansion history through four key parameters: the present-day value of the DE equation of state ($w_0$), its initial value ($w_m$), the scale factor depicting transition from $w_m$ to $w_0$ occurs ($a_t$), and the steepness of this transition ($\Delta_{\rm de}$). We constrain the model using CMB data from Planck, BAO from DESI DR2, and three distinct compilations of Type Ia Supernovae: PantheonPlus, DESY5, and Union3. Our results show that constraining all four parameters remains difficult: $a_t$ is not constrained by any dataset, while the remaining three parameters can be constrained only when all observational probes are combined (with the exception of DESY5). The results further show that DE has a quintessential nature at present ($w_0 > -1$), while $w_m$ is negative, indicating a phantom-like behaviour at early times. Interestingly, despite its larger parameter space, the proposed DDE model is preferred over the $\Lambda$CDM scenario, based on both $\Delta\chi^2$ and Bayesian evidence, for certain combined datasets, particularly CMB+BAO+DESY5 and CMB+BAO+Union3. + oai:arXiv.org:2512.09866v1 + astro-ph.CO + gr-qc + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.1088/1742-6596/2691/1/012033 - 2024 J. Phys.: Conf. Ser. 2691 012033 - Chengcheng Wen, Shu Jiang, Mingming Xu, Lingyi Kong, Jinning He + Hanyu Cheng, Supriya Pan, Eleonora Di Valentino - Optical polarimetry of the accreting black hole X-ray binary Swift J1727.8$-$1613 over the state transition and radio ejections - https://arxiv.org/abs/2512.08716 - arXiv:2512.08716v1 Announce Type: new -Abstract: We present the first optical ($BVR$) polarimetric observations of Swift J1727.8$-$1613 during its 2023--2024 outburst. Observations were performed during the X-ray hard-to-soft state transition, the soft state and the decaying hard state of the source. For the vast majority of nights, we detect statistically significant polarization of ${\approx}1$\%, a fraction of which is of interstellar origin. We find a significant change of polarization coinciding in time with discrete radio ejections. The direction of this polarization variation differs from the directions inferred from the X-ray, sub-mm and radio polarization angles, as well as from the resolved jet orientation. After correcting for the interstellar component, we find that the intrinsic polarization degree remained approximately constant at PD $\approx 0.3$\% throughout the hard-intermediate state. We explore several possible origins for the polarization and conclude that it is most plausibly produced by scattering within the optically thin accretion disk wind. The intrinsic polarization angle, PA $\approx-15\deg$, is notably offset from the jet axis, which we interpret as evidence for a misalignment between the black hole spin and the orbital axis. - oai:arXiv.org:2512.08716v1 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Binary asteroids in mean-motion resonances + https://arxiv.org/abs/2512.09868 + arXiv:2512.09868v1 Announce Type: new +Abstract: The purpose of this study is to investigate the relation between binary asteroids and mean motion resonances (MMRs). For more than 700 asteroids from two catalogues, the Johnston Archive [Johnston, 2024] and the Gaia DR3 VizieR list of binary candidates from Liberato et al. [2024], we applied a resonance identification algorithm, treating all planetary perturbations. Our results showed that the presence of binary asteroids in MMRs largely depends on their dynamical class. The highest percentage, more than 30%, is found in the Trans- Neptunian region, where most of these objects have exhibited resonant librations longer than 10 Myr. For the main-belt asteroid pairs, + this percentage is about 10-12%. Contrary to expectations, the more unstable region populated with NEOs, showed a higher percentage of resonant pairs (above 17%), but with temporal resonant captures. These results could indicate that the mean motion resonances, particularly the stronger ones, could play a role in the evolution and formation of binary systems. Finally, we highlight that in the present paper, 82 resonant binary asteroids are newly identified. + oai:arXiv.org:2512.09868v1 + astro-ph.EP + Thu, 11 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Anagha P. Nitindala, Alexandra Veledina, Vadim Kravtsov, Andrei V. Berdyugin, Mar\'ia Alejandra D\'iaz Teodori, Vilppu Piirola, Takeshi Sakanoi, Masato Kagitani, Svetlana V. Berdyugina, Juri Poutanen + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Natasa Todorovic, Ivana Milic Zitnik - Neutrino mass constraints in the context of 4-parameter dark energy equation of state and DESI DR2 observations - https://arxiv.org/abs/2512.08752 - arXiv:2512.08752v1 Announce Type: new -Abstract: Cosmological constraints on the total neutrino mass, $\sum m_\nu$, are strongly shaped by assumptions about the dark-energy equation of state due to the well-known degeneracy between massive neutrinos and late-time cosmic acceleration. In this work, we move beyond the two-parameter Chevallier-Polarski-Linder (CPL) form adopted in recent DESI analyses and re-examine neutrino mass constraints using a flexible four-parameter dark energy equation of state (4pDE). We implement the 4pDE model in a modified version of CLASS and perform a full MCMC analysis using Planck, DESI DR2 BAO, and Pantheon+ data. Relative to our previous 4pDE study based on pre-DESI BAO datasets, the inclusion of DESI DR2 substantially tightens the constraints on the transition parameters while still yielding a relaxed neutrino-mass bound compared to $\Lambda$CDM, $\sum m_\nu < 0.101$ eV ($95\%$ C.L.). This upper limit is more stringent than the DESI DR2 constraint obtained within the $w_0w_a$CDM framework. From the best-fit parameters, we reconstruct the evolution of the 4pDE equation of state along with both $68\%$ and $95\%$C.L. We do not find a statistically significant phantom-crossing at $z \sim 0.5$, consistent with the conclusion from the DESI collaboration; at higher redshifts, the reconstructed $w(z)$ follows the CPL evolution and deviates only at low redshift. Additionally we also find reduction in $\Delta \chi^2_{\rm min}=-7.3$ compared to $\Lambda$CDM model. - oai:arXiv.org:2512.08752v1 - astro-ph.CO + GFH-v2 Pipeline for Searches of Long-Transient Gravitational Waves from Newborn Magnetars + https://arxiv.org/abs/2512.09878 + arXiv:2512.09878v1 Announce Type: new +Abstract: This paper presents an enhanced methodology for searching long transient gravitational waves associated with a newborn magnetar using a strongly improved version of the generalized Frequency Hough Transform algorithm, called GFH-v2. We describe the main developments introduced relative to the original implementation and outline the optimized parameter-space selection used in the search. We then compute the theoretical sensitivity of the method and compare it with an empirical sensitivity estimate obtained by injecting simulated signals into LIGO-Virgo-KAGRA O4a data. The updated framework achieves improved sensitivity and computational performance. These results provide a robust basis for future directed searches for long-transient gravitational-wave signals from core-collapse supernovae and other transient events in current and upcoming observing runs. + oai:arXiv.org:2512.09878v1 + astro-ph.IM gr-qc - hep-ph - hep-th - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Gowri S Nair, Amlan Chakraborty, Luca Amendola, Subinoy Das + Sandhya Sajith Menon, Lorenzo Pierini, Pia Astone, Cristiano Palomba, Lorenzo Silvestri, Sabrina D'Antonio, Simone Dall'Osso, Francesco Safai Tehrani, Stefano Dal Pra, Gaetano Dinatale, Sergio Frasca, Dafne Guetta, Paola Leaci, Alessio Orlandi - Backwards Gamma-Ray Bursts: Searching for Exploding Primordial Black Holes in Short-Duration GRB Catalogs - https://arxiv.org/abs/2512.08778 - arXiv:2512.08778v1 Announce Type: new -Abstract: We present a systematic search for signatures of terminal black-hole evaporation in short gamma-ray burst (sGRB) catalogs. An exploding primordial black hole (PBH) undergoing final-stage Hawking radiation is predicted to produce a distinctive "backwards burst"-a very short, spectrally hard transient with monotonically increasing flux and little or no longer-wavelength afterglow. We develop a forward-modeling framework that directly compares theoretical PBH evaporation light curves, computed with full Standard Model particle content and detector response folding, against empirical GRB pulse templates. Analyzing 39 well-characterized Swift sGRBs with non-detected or extremely faint afterglows, we find that all events exhibit fast-rise, slow-decay temporal profiles inconsistent with the PBH prediction. Model comparison via Akaike and Bayesian information criteria decisively favors conventional FRED or ERCA fits over the PBH template for every burst. No candidates for terminal PBH evaporation are identified. The null result yields an upper bound on the local PBH explosion rate density $R_{\mathrm{PBH}} \lesssim 10^5~\mathrm{pc}^{-3}~\mathrm{yr}^{-1}$, comparable to constraints from dedicated TeV $\gamma$-ray searches. Our methodology establishes a robust template-matching approach that can be scaled to larger multi-instrument catalogs, providing a foundation for future searches targeting this unique signature of quantum gravity and early-Universe physics. - oai:arXiv.org:2512.08778v1 - astro-ph.HE - astro-ph.CO + Clumpy, dense gas in the outflow of NGC 1266 + https://arxiv.org/abs/2512.09889 + arXiv:2512.09889v1 Announce Type: new +Abstract: Outflows are one of the most spectacular mechanisms through which active galactic nuclei (AGN) impact their host galaxy, though the role of AGN-driven outflows in global star formation regulation across the galaxy population is unclear. NGC 1266 is an excellent case study for investigating the outflows and star formation quenching because it is a nearby (D\sim30 Mpc) AGN host galaxy with an outflow driving shocks through the interstellar medium (ISM) and has recently quenched its star formation outside the nucleus. While previous works have studied the molecular outflow from its CO emission, to fully characterize the impact the outflow has on the ISM observations probing the dense, cold gas are necessary. Our ALMA cycle 0 observations do not detect a molecular outflow in 13CO(2-1) and yield a lower limit 12CO/13CO \geq 250, suggesting a highly optically thin CO outflow with low 13CO abundance. In contrast, we detect substantial HCN(1-0) emission in the outflow, with an HCN(1-0)/12CO(1-0) ratio of 0.09, consistent with global measurements of many star-forming galaxies and Luminous InfraRed Galaxies (LIRGs). We conclude that the CO emission traces a diffuse component of the molecular gas with a low optical depth, whereas the HCN(1-0) traces dense clumps of gas entrained in the outflow. We measure an upper limit molecular outflow rate of < 85 Msun/yr. Assuming the ongoing nuclear star formation and outflow continue at the same rates, NGC 1266 will deplete its gas reservoirs in 450 Myr or longer, indicating that relatively low-level AGN feedback is capable of gradually expelling the molecular gas reservoir after a rapid quenching event. + oai:arXiv.org:2512.09889v1 astro-ph.GA - hep-ph - hep-th - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Stefano Profumo, Kally Wen - - - Neutrino pair bremsstrahlung due to electromagnetic collisions in neutron star cores revisited - https://arxiv.org/abs/2512.08780 - arXiv:2512.08780v1 Announce Type: new -Abstract: We reconsider the problem of neutrino pair bremsstrahlung emission originating from the electromagnetic collisions of charged particles in nucleonic ($npe\mu$) neutron star cores. Two limiting cases are considered: (i) protons are in the normal state and (ii) protons are in the superconducting state. In both cases, the dominant contribution to the bremsstrahlung emissivity $Q^{\mathrm{em}}_{\mathrm{Br}}$ comes from the transverse part of in-medium electromagnetic interactions. For non-superconducting matter, we obtain an unusual $Q^{\mathrm{em}}_{\mathrm{Br}}\propto T^{23/3}$ temperature dependence due to the dynamical character of plasma screening in the transverse channel, but considerably smaller values of $Q^{\mathrm{em}}_{\mathrm{Br}}$ than in previous studies, rendering the considered process unimportant in practice. In contrast, for superconducting and superfluid matter, the neutrino emission processes involving nucleons are suppressed and $Q^{\mathrm{em}}_{\mathrm{Br}}$ due to lepton collisions provides the residual contribution to the neutrino emissivity of neutron star core matter. In the superconducting case, the plasma screening becomes static and the standard $Q^{\mathrm{em}}_{\mathrm{Br}}\propto T^{8}$ temperature scaling is restored. Simple analytical expressions for $Q^{\mathrm{em}}_{\mathrm{Br}}$ in both limiting cases are provided. - oai:arXiv.org:2512.08780v1 - astro-ph.HE - hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - P. S. Shternin + Justin Atsushi Otter, Katherine Alatalo, Pallavi Patil, Maya Skarbinski, Lauren Dysarz, Mark Lacy, Maria J. Jimenez-Donaire, Susanne Aalto, Timothy A. Davis, Antoniu Fodor, K. Decker French, Nanase Harada, Timothy Heckman, Ryo Kishikawa, Sebastian Lopez, Yuanze Luo, Sergio Martin, Anne M. Medling, Kristina Nyland, Andreea Petric, Namrata Roy, Mamiko Sato, Elizaveta Sazonova, Adam Smercina, Akshat Tripathi - The Radius of PSR J0437-4715 from NICER Data - https://arxiv.org/abs/2512.08790 - arXiv:2512.08790v1 Announce Type: new -Abstract: Neutron star Interior Composition Explorer (NICER) data have been used to estimate the masses and radii of the rotation-powered millisecond pulsars PSR J0030$+$0451, PSR J0740$+$6620, PSR J0437$-$4715, PSR J1231$-$1411, and PSR J0614$-$3329, sometimes in joint analyses with X-ray Multi-Mirror (XMM-Newton) data. These measurements provide invaluable information about the properties of cold, catalyzed matter beyond nuclear saturation density. Here we present the results of our modeling of NICER data on PSR J0437$-$4715 using several different models of hot thermal X-ray emitting spots on the stellar surface. For this pulsar, previous Nuclear Spectroscopic Telescope Array (NuSTAR) observations established that there is also a modulated nonthermal component to the emission, but the previously published analysis of NICER data did not model this component. We find that the Bayesian evidence is significantly higher when the modulated nonthermal component is included, and that omission of this component leads to poor fits to the bolometric NICER data and thus risks bias in the resulting radius estimates. Our models, which we pursue to inferential convergence, therefore have modulated nonthermal emission, and our headline model has in addition three uniform-temperature thermally-emitting circular spots. Using this model, the symmetric 68% credible range in the radius is 11.8 km to 15.1 km, which at the independently-measured mass of $M=1.418\pm 0.044~M_\odot$ is consistent with previous reports of the radius of the $\sim 1.4~M_\odot$ pulsar PSR J0030$+$0451. We discuss the implications of this measurement for the equation of state of dense matter. - oai:arXiv.org:2512.08790v1 - astro-ph.HE - gr-qc - nucl-th - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - M. C. Miller, A. J. Dittmann, I. M. Holt, F. K. Lamb, C. Chirenti, Z. Arzoumanian, J. Berteaud, S. Bogdanov, K. C. Gendreau, W. C. G. Ho, S. M. Morsink, P. S. Ray, R. A. Remillard, Z. Wadiasingh, M. T. Wolff - - - Predicting Infall Time of Milky-Way Satellites via Machine Learning - https://arxiv.org/abs/2512.08792 - arXiv:2512.08792v1 Announce Type: new -Abstract: The properties of dwarf galaxies provide essential insight into galaxy formation and evolution in a hierarchical universe. Among various physical quantities, identifying their infall times to host galaxies is crucial, as these times encode key information such as star formation histories. However, estimating infall times remains challenging due to the complex interplay between different physical processes and the lack of consensus among existing methods. We propose a fast and interpretable method to predict the infall time of dwarf satellites using LightGBM, a gradient-boosting decision tree algorithm. Our model is trained on satellites from 30 Milky Way (MW)-like host galaxies generated by A-SLOTH, a semi-analytic model calibrated using observational constraints, including those from the MW and its satellites. To balance predictive ability and observational applicability, we adopt $\tau_{90}$, [Fe/H], and $M_{\star}$ as input features. Since satellites with prior group membership hinder accurate MW infall predictions, we exclude them from the training data. As a result, the model achieves the best average mean squared error (MSE) of 5.04 in the A-SLOTH data set. Our model also shows good agreement with existing observational studies of MW satellites, although some discrepancies remain due to a few outliers such as CVn II and UMa I. In addition, for satellites experiencing prior infall events before MW-like host infall, the model predicts the timing of the first infall with a significantly lower MSE of 1.66, indicating the importance of the earliest infall in the quenching process of satellite galaxies. - oai:arXiv.org:2512.08792v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Seungyeon Kim, Myoungwon Jeon, Seongjun Hyung - - - Euclid Quick Data Release (Q1): Euclid spectroscopy of QSOs. 1. Identification and redshift determination of 3500 bright QSOs - https://arxiv.org/abs/2512.08803 - arXiv:2512.08803v1 Announce Type: new -Abstract: The slitless spectroscopy mode of the NISP onboard Euclid has enabled efficient spectroscopy of objects within a large FoV. We present a large and homogeneous sample of bright quasars identified from the Euclid Quick Data Release (Q1) by combining high-purity candidate selections from Gaia and WISE with the NISP spectra. Through visual inspection of the Euclid spectra of these quasar candidates, we identify approximately 3500 quasars with reliable redshifts at $0<z\lesssim 4.8$. We generate the first Euclid composite spectrum of quasars covering rest-frame NUV to NIR wavelengths without telluric lines, which will be pivotal to NIR quasar spectral analysis. We obtain an empirical spectroscopic depth of $J_{\rm E}\lesssim 21.5$ and $H_{\rm E}\lesssim 21.3$ at the sensitivity of the Wide Field Survey, beyond which the number of securely identified quasars declines sharply. We analyse VIS morphologies using Sersic and CAS metrics, and a deep-learning PSF fraction to track nuclear dominance. At low redshift ($z<0.5$), obvious host structures are common and a single Sersic model fits about half of the sources; at intermediate redshift ($0.5<z<2$), the nuclear component dominates, with 90% of the Sersic fits saturating at the upper index limit. In this intermediate redshift regime, $f_{\rm PSF}$ is available, and we use it as a more reliable compactness measure than the single-Sersic and CAS parameters to quantify nuclear versus host emission. We also explore the novel Euclid NIR colour space and discuss the role of these quasars in refining AGN selection techniques for future Euclid data releases. Our results highlight the potential of Euclid spectroscopy to advance quasar surveys and enable the construction of more complete AGN catalogues. The spectroscopic bright quasar catalogue of this work, and the composite quasar spectrum, will be available at https://cdsarc.cds.unistra.fr/. (abridged) - oai:arXiv.org:2512.08803v1 + Self-consistent secondary cosmic microwave background anisotropies and extragalactic foregrounds in the FLAMINGO simulations + https://arxiv.org/abs/2512.09891 + arXiv:2512.09891v1 Announce Type: new +Abstract: Secondary anisotropies in the cosmic microwave background (CMB) contain information that can be used to test both cosmological models and models of galaxy formation. Starting from lightcone-based HEALPix maps and catalogues, we present a new set of mock CMB maps constructed in a self-consistent manner from the FLAMINGO suite of cosmological hydrodynamical simulations, including CMB lensing, thermal and kinetic Sunyaev-Zeldovich effects, cosmic infrared background, radio point source and anisotropic screening maps. We show that these simulations reproduce a wide range of observational constraints. We also compare our simulations with previous predictions based on dark matter-only simulations which generally model the secondary anisotropies independently from one another, concluding that our hydrodynamical simulation mocks perform at least as well as previous mocks in matching the observations whilst retaining self-consistency in the predictions of the different components. Using the model variations in FLAMINGO, we further explore how the signals depend on cosmology and feedback modelling, and we predict cross-correlations between some of the signals that differ significantly from those in previous mocks. The mock CMB maps should provide a valuable resource for exploring correlations between different secondary anisotropies and other large-scale structure tracers, and can be applied to forecasts for upcoming surveys. + oai:arXiv.org:2512.09891v1 + astro-ph.CO astro-ph.GA - astro-ph.IM - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Euclid Collaboration, Y. Fu (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands, Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands), R. Bouwens (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), K. I. Caputi (Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands, Cosmic Dawn Center), D. Vergani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), M. Scialpi (Dipartimento di Fisica e Astronomia, Universit\`a di Firenze, via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy, University of Trento, Via Sommarive 14, I-38123 Trento, Italy, INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Firenze, Italy), B. Margalef-Bentabol (SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD, Groningen, The Netherlands), L. Wang (SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD, Groningen, The Netherlands, Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands), M. Bolzonella (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), M. Banerji (School of Physics \& Astronomy, University of Southampton, Highfield Campus, Southampton SO17 1BJ, UK), E. Ba\~nados (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), A. Feltre (INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Firenze, Italy), Y. Toba (Department of Physical Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan, Academia Sinica Institute of Astronomy and Astrophysics), J. Calhau (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), F. Tarsitano (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland, Institute for Particle Physics and Astrophysics, Dept. of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland), P. A. C. Cunha (Dipartimento di Fisica e Astronomia, Universit\`a di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy, Faculdade de Ci\^encias da Universidade do Porto, Rua do Campo de Alegre, 4150-007 Porto, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal), A. Humphrey (Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal, DTx -- Digital Transformation CoLAB, Building 1, Azur\'em Campus, University of Minho, 4800-058 Guimar\~aes, Portugal), G. Vietri (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), F. Mannucci (INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Firenze, Italy), S. Bisogni (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), F. Ricci (Department of Mathematics and Physics, Roma Tre University, Via della Vasca Navale 84, 00146 Rome, Italy, INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), H. Landt (Department of Physics, Centre for Extragalactic Astronomy, Durham University, South Road, Durham, DH1 3LE, UK), L. Spinoglio (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), T. Matamoro Zatarain (School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK), D. Stern (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), M. J. Page (Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK), D. M. Alexander (Department of Physics, Centre for Extragalactic Astronomy, Durham University, South Road, Durham, DH1 3LE, UK), G. Zamorani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), W. Roster (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), M. Salvato (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), Y. Copin (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), J. G. Sorce (Univ. Lille, CNRS, Centrale Lille, UMR 9189 CRIStAL, 59000 Lille, France, Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), D. Scott (Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada), Y. -H. Zhang (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), E. Lusso (Dipartimento di Fisica e Astronomia, Universit\`a di Firenze, via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy, INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Firenze, Italy), J. Wolf (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), D. Yang (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), H. J. A. Rottgering (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), B. Laloux (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy, Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), M. Siudek (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain, Institute of Space Sciences), S. Belladitta (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), Q. Liu (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), V. Allevato (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), S. Andreon (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), N. Auricchio (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), C. Baccigalupi (IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy), M. Baldi (Dipartimento di Fisica e Astronomia, Universit\`a di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), A. Balestra (INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), S. Bardelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), P. Battaglia (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), A. Biviano (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), E. Branchini (Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), M. Brescia (Department of Physics "E. Pancini", University Federico II, Via Cinthia 6, 80126, Napoli, Italy, INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), J. Brinchmann (Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal, Faculdade de Ci\^encias da Universidade do Porto, Rua do Campo de Alegre, 4150-007 Porto, Portugal, European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany), S. Camera (Dipartimento di Fisica, Universit\`a degli Studi di Torino, Via P. Giuria 1, 10125 Torino, Italy, INFN-Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy, INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), G. Ca\~nas-Herrera (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands, Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), V. Capobianco (INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), C. Carbone (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), J. Carretero (Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), S. Casas (Institute for Theoretical Particle Physics and Cosmology, Deutsches Zentrum f\"ur Luft- und Raumfahrt e. V), M. Castellano (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), G. Castignani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Cavuoti (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy, INFN section of Naples, Via Cinthia 6, 80126, Napoli, Italy), K. C. Chambers (Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA), A. Cimatti (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), C. Colodro-Conde (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain), G. Congedo (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), C. J. Conselice (Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK), L. Conversi (European Space Agency/ESRIN, Largo Galileo Galilei 1, 00044 Frascati, Roma, Italy, ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), A. Costille (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), F. Courbin (Institut de Ci\`encies del Cosmos, Instituci\'o Catalana de Recerca i Estudis Avan\c{c}ats), H. M. Courtois (UCB Lyon 1, CNRS/IN2P3, IUF, IP2I Lyon, 4 rue Enrico Fermi, 69622 Villeurbanne, France), M. Cropper (Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK), A. Da Silva (Departamento de F\'isica, Faculdade de Ci\^encias, Universidade de Lisboa, Edif\'icio C8, Campo Grande, PT1749-016 Lisboa, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal), H. Degaudenzi (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), G. De Lucia (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), C. Dolding (Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK), H. Dole (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), F. Dubath (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), C. A. J. Duncan (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), X. Dupac (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), S. Dusini (INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), S. Escoffier (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), M. Fabricius (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany, Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr. 1, 81679 M\"unchen, Germany), M. Farina (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), R. Farinelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Ferriol (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), F. Finelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), P. Fosalba (Institut d'Estudis Espacials de Catalunya, Institute of Space Sciences), N. Fourmanoit (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), M. Frailis (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), E. Franceschi (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), P. Franzetti (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), M. Fumana (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), S. Galeotta (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), K. George (University Observatory, LMU Faculty of Physics, Scheinerstr. 1, 81679 Munich, Germany), W. Gillard (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), B. Gillis (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), C. Giocoli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), J. Gracia-Carpio (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), A. Grazian (INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), F. Grupp (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany, Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr. 1, 81679 M\"unchen, Germany), L. Guzzo (Dipartimento di Fisica "Aldo Pontremoli", Universit\`a degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy, INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy, INFN-Sezione di Milano, Via Celoria 16, 20133 Milano, Italy), S. V. H. Haugan (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), H. Hoekstra (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), W. Holmes (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), I. M. Hook (Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK), F. Hormuth (Felix Hormuth Engineering, Goethestr. 17, 69181 Leimen, Germany), A. Hornstrup (Technical University of Denmark, Elektrovej 327, 2800 Kgs. Lyngby, Denmark, Cosmic Dawn Center), K. Jahnke (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), M. Jhabvala (NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA), B. Joachimi (Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK), E. Keih\"anen (Department of Physics and Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), S. Kermiche (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), A. Kiessling (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), B. Kubik (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), M. K\"ummel (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr. 1, 81679 M\"unchen, Germany), M. Kunz (Universit\'e de Gen\`eve, D\'epartement de Physique Th\'eorique and Centre for Astroparticle Physics, 24 quai Ernest-Ansermet, CH-1211 Gen\`eve 4, Switzerland), H. Kurki-Suonio (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), R. Laureijs (Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands), A. M. C. Le Brun (Laboratoire d'etude de l'Univers et des phenomenes eXtremes, Observatoire de Paris, Universit\'e PSL, Sorbonne Universit\'e, CNRS, 92190 Meudon, France), S. Ligori (INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), P. B. Lilje (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), V. Lindholm (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), I. Lloro (SKAO, Jodrell Bank, Lower Withington, Macclesfield SK11 9FT, UK), G. Mainetti (Centre de Calcul de l'IN2P3/CNRS, 21 avenue Pierre de Coubertin 69627 Villeurbanne Cedex, France), D. Maino (Dipartimento di Fisica "Aldo Pontremoli", Universit\`a degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy, INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy, INFN-Sezione di Milano, Via Celoria 16, 20133 Milano, Italy), E. Maiorano (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), O. Mansutti (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), S. Marcin (University of Applied Sciences and Arts of Northwestern Switzerland, School of Computer Science, 5210 Windisch, Switzerland), O. Marggraf (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), K. Markovic (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), M. Martinelli (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy, INFN-Sezione di Roma, Piazzale Aldo Moro, 2 - c/o Dipartimento di Fisica, Edificio G. Marconi, 00185 Roma, Italy), N. Martinet (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), F. Marulli (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), R. J. Massey (Department of Physics, Institute for Computational Cosmology, Durham University, South Road, Durham, DH1 3LE, UK), E. Medinaceli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Mei (Universit\'e Paris Cit\'e, CNRS, Astroparticule et Cosmologie, 75013 Paris, France, CNRS-UCB International Research Laboratory, Centre Pierre Bin\'etruy, IRL2007, CPB-IN2P3, Berkeley, USA), M. Melchior (University of Applied Sciences and Arts of Northwestern Switzerland, School of Engineering, 5210 Windisch, Switzerland), Y. Mellier (Institut d'Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France, Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, France), M. Meneghetti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), E. Merlin (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), G. Meylan (Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique F\'ed\'erale de Lausanne), A. Mora (Telespazio UK S.L. for European Space Agency), M. Moresco (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), L. Moscardini (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), R. Nakajima (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), C. Neissner (Institut de F\'isica d'Altes Energies, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), R. C. Nichol (School of Mathematics and Physics, University of Surrey, Guildford, Surrey, GU2 7XH, UK), S. -M. Niemi (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands), C. Padilla (Institut de F\'isica d'Altes Energies), S. Paltani (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), F. Pasian (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), K. Pedersen (DARK, Niels Bohr Institute, University of Copenhagen, Jagtvej 155, 2200 Copenhagen, Denmark), W. J. Percival (Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada), V. Pettorino (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands), S. Pires (Universit\'e Paris-Saclay, Universit\'e Paris Cit\'e, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France), G. Polenta (Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy), M. Poncet (Centre National d'Etudes Spatiales -- Centre spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France), L. A. Popa (Institute of Space Science, Str. Atomistilor, nr. 409 M\u{a}gurele, Ilfov, 077125, Romania), L. Pozzetti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), F. Raison (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), R. Rebolo (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Consejo Superior de Investigaciones Cientificas, Calle Serrano 117, 28006 Madrid, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), A. Renzi (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), J. Rhodes (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), G. Riccio (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), E. Romelli (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), M. Roncarelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), E. Rossetti (Dipartimento di Fisica e Astronomia, Universit\`a di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy), R. Saglia (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr. 1, 81679 M\"unchen, Germany, Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), Z. Sakr (Institut f\"ur Theoretische Physik, University of Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany, Institut de Recherche en Astrophysique et Plan\'etologie, Universit\'e St Joseph, Faculty of Sciences, Beirut, Lebanon), D. Sapone (Departamento de F\'isica, FCFM, Universidad de Chile, Blanco Encalada 2008, Santiago, Chile), B. Sartoris (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr. 1, 81679 M\"unchen, Germany, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), M. Schirmer (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), P. Schneider (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), T. Schrabback (Universit\"at Innsbruck, Institut f\"ur Astro- und Teilchenphysik, Technikerstr. 25/8, 6020 Innsbruck, Austria), M. Scodeggio (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), A. Secroun (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), E. Sefusatti (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy), G. Seidel (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), S. Serrano (Institut d'Estudis Espacials de Catalunya, Satlantis, University Science Park, Sede Bld 48940, Leioa-Bilbao, Spain, Institute of Space Sciences), P. Simon (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), C. Sirignano (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), G. Sirri (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), L. Stanco (INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), J. -L. Starck (Universit\'e Paris-Saclay, Universit\'e Paris Cit\'e, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France), J. Steinwagner (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), C. Surace (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), P. Tallada-Cresp\'i (Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), D. Tavagnacco (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), A. N. Taylor (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), H. I. Teplitz (Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA), I. Tereno (Departamento de F\'isica, Faculdade de Ci\^encias, Universidade de Lisboa, Edif\'icio C8, Campo Grande, PT1749-016 Lisboa, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal), N. Tessore (Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK), S. Toft (Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen, Jagtvej 128, 2200 Copenhagen, Denmark), R. Toledo-Moreo (Universidad Polit\'ecnica de Cartagena, Departamento de Electr\'onica y Tecnolog\'ia de Computadoras, Plaza del Hospital 1, 30202 Cartagena, Spain), F. Torradeflot (Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra, Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas), I. Tutusaus (Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Institut de Recherche en Astrophysique et Plan\'etologie), L. Valenziano (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), J. Valiviita (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), T. Vassallo (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), A. Veropalumbo (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy, Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy), D. Vibert (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), Y. Wang (Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA), J. Weller (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr. 1, 81679 M\"unchen, Germany, Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), A. Zacchei (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), E. Zucca (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), M. Ballardini (Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), E. Bozzo (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), C. Burigana (INAF, Istituto di Radioastronomia, Via Piero Gobetti 101, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), R. Cabanac (Institut de Recherche en Astrophysique et Plan\'etologie), M. Calabrese (Astronomical Observatory of the Autonomous Region of the Aosta Valley, INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), A. Cappi (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, Universit\'e C\^ote d'Azur, Observatoire de la C\^ote d'Azur, CNRS, Laboratoire Lagrange, Bd de l'Observatoire, CS 34229, 06304 Nice cedex 4, France), D. Di Ferdinando (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), J. A. Escartin Vigo (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), L. Gabarra (Department of Physics, Oxford University, Keble Road, Oxford OX1 3RH, UK), W. G. Hartley (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), M. Huertas-Company (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain, Universit\'e PSL, Observatoire de Paris, Sorbonne Universit\'e, CNRS, LERMA, 75014, Paris, France, Universit\'e Paris-Cit\'e, 5 Rue Thomas Mann, 75013, Paris, France), J. Mart\'in-Fleitas (Aurora Technology for European Space Agency), S. Matthew (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), N. Mauri (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), R. B. Metcalf (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), A. A. Nucita (Department of Mathematics and Physics E. De Giorgi, University of Salento, Via per Arnesano, CP-I93, 73100, Lecce, Italy, INFN, Sezione di Lecce, Via per Arnesano, CP-193, 73100, Lecce, Italy, INAF-Sezione di Lecce, c/o Dipartimento Matematica e Fisica, Via per Arnesano, 73100, Lecce, Italy), A. Pezzotta (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), M. P\"ontinen (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland), C. Porciani (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), I. Risso (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy), V. Scottez (Institut d'Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France, ICL, Junia, Universit\'e Catholique de Lille, LITL, 59000 Lille, France), M. Sereno (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), M. Tenti (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), M. Viel (IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy), M. Wiesmann (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), Y. Akrami (Instituto de F\'isica Te\'orica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain, CERCA/ISO, Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA), S. Alvi (Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), I. T. Andika (Technical University of Munich, TUM School of Natural Sciences, Physics Department, James-Franck-Str. 1, 85748 Garching, Germany, Max-Planck-Institut f\"ur Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany), S. Anselmi (INFN-Padova, Via Marzolo 8, 35131 Padova, Italy, Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, Laboratoire Univers et Th\'eorie, Observatoire de Paris, Universit\'e PSL, Universit\'e Paris Cit\'e, CNRS, 92190 Meudon, France), M. Archidiacono (Dipartimento di Fisica "Aldo Pontremoli", Universit\`a degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy, INFN-Sezione di Milano, Via Celoria 16, 20133 Milano, Italy), F. Atrio-Barandela (Departamento de F\'isica Fundamental. Universidad de Salamanca. Plaza de la Merced s/n. 37008 Salamanca, Spain), E. Aubourg (Universit\'e Paris Cit\'e, CNRS, Astroparticule et Cosmologie, 75013 Paris, France, IRFU, CEA, Universit\'e Paris-Saclay 91191 Gif-sur-Yvette Cedex, France), D. Bertacca (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), M. Bethermin (Universit\'e de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France), L. Bisigello (INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), A. Blanchard (Institut de Recherche en Astrophysique et Plan\'etologie), L. Blot (Center for Data-Driven Discovery, Kavli IPMU, Laboratoire d'etude de l'Univers et des phenomenes eXtremes, Observatoire de Paris, Universit\'e PSL, Sorbonne Universit\'e, CNRS, 92190 Meudon, France), M. Bonici (Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), S. Borgani (Dipartimento di Fisica - Sezione di Astronomia, Universit\`a di Trieste, Via Tiepolo 11, 34131 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy), M. L. Brown (Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK), S. Bruton (California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA), A. Calabro (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), B. Camacho Quevedo (IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), F. Caro (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), C. S. Carvalho (Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal), T. Castro (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy), F. Cogato (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Conseil (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), A. R. Cooray (Department of Physics \& Astronomy, University of California Irvine, Irvine CA 92697, USA), O. Cucciati (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), G. Daste (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), F. De Paolis (Department of Mathematics and Physics E. De Giorgi, University of Salento, Via per Arnesano, CP-I93, 73100, Lecce, Italy, INFN, Sezione di Lecce, Via per Arnesano, CP-193, 73100, Lecce, Italy, INAF-Sezione di Lecce, c/o Dipartimento Matematica e Fisica, Via per Arnesano, 73100, Lecce, Italy), G. Desprez (Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands), A. D\'iaz-S\'anchez (Departamento F\'isica Aplicada, Universidad Polit\'ecnica de Cartagena, Campus Muralla del Mar, 30202 Cartagena, Murcia, Spain), J. J. Diaz (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain), S. Di Domizio (Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy), J. M. Diego (Instituto de F\'isica de Cantabria, Edificio Juan Jord\'a, Avenida de los Castros, 39005 Santander, Spain), P. Dimauro (Observatorio Nacional, Rua General Jose Cristino, 77-Bairro Imperial de Sao Cristovao, Rio de Janeiro, 20921-400, Brazil, INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), P. -A. Duc (Universit\'e de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France), M. Y. Elkhashab (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, Dipartimento di Fisica - Sezione di Astronomia, Universit\`a di Trieste, Via Tiepolo 11, 34131 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), A. Enia (Dipartimento di Fisica e Astronomia, Universit\`a di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), Y. Fang (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr. 1, 81679 M\"unchen, Germany), A. G. Ferrari (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), A. Finoguenov (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland), F. Fontanot (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), A. Franco (INFN, Sezione di Lecce, Via per Arnesano, CP-193, 73100, Lecce, Italy, Department of Mathematics and Physics E. De Giorgi, University of Salento, Via per Arnesano, CP-I93, 73100, Lecce, Italy, INAF-Sezione di Lecce, c/o Dipartimento Matematica e Fisica, Via per Arnesano, 73100, Lecce, Italy), K. Ganga (Universit\'e Paris Cit\'e, CNRS, Astroparticule et Cosmologie, 75013 Paris, France), J. Garc\'ia-Bellido (Instituto de F\'isica Te\'orica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain), T. Gasparetto (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), V. Gautard (CEA Saclay, DFR/IRFU, Service d'Astrophysique, Bat. 709, 91191 Gif-sur-Yvette, France), E. Gaztanaga (Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK), F. Giacomini (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), F. Gianotti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), G. Gozaliasl (Department of Computer Science, Aalto University, PO Box 15400, Espoo, FI-00 076, Finland, Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland), M. Gray (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), M. Guidi (Dipartimento di Fisica e Astronomia, Universit\`a di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), C. M. Gutierrez (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), A. Hall (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), C. Hern\'andez-Monteagudo (Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain, Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain), H. Hildebrandt (Ruhr University Bochum, Faculty of Physics and Astronomy, Astronomical Institute), J. Hjorth (DARK, Niels Bohr Institute, University of Copenhagen, Jagtvej 155, 2200 Copenhagen, Denmark), J. J. E. Kajava (Department of Physics and Astronomy, Vesilinnantie 5, University of Turku, 20014 Turku, Finland, Serco for European Space Agency), Y. Kang (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), V. Kansal (ARC Centre of Excellence for Dark Matter Particle Physics, Melbourne, Australia, Centre for Astrophysics \& Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia), D. Karagiannis (Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, Department of Physics and Astronomy, University of the Western Cape, Bellville, Cape Town, 7535, South Africa), K. Kiiveri (Department of Physics and Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), J. Kim (Department of Physics, Oxford University, Keble Road, Oxford OX1 3RH, UK), C. C. Kirkpatrick (Department of Physics and Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), S. Kruk (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), V. Le Brun (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), J. Le Graet (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), L. Legrand (DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA, UK, Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge, CB3 0HA, UK), M. Lembo (Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, France, Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), F. Lepori (Department of Astrophysics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland), G. Leroy (Department of Physics, Centre for Extragalactic Astronomy, Durham University, South Road, Durham, DH1 3LE, UK, Department of Physics, Institute for Computational Cosmology, Durham University, South Road, Durham, DH1 3LE, UK), G. F. Lesci (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), J. Lesgourgues (Institute for Theoretical Particle Physics and Cosmology), T. I. Liaudat (IRFU, CEA, Universit\'e Paris-Saclay 91191 Gif-sur-Yvette Cedex, France), A. Loureiro (Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, Stockholm, SE-106 91, Sweden, Astrophysics Group, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK), J. Macias-Perez (Univ. Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 53, Avenue des Martyrs, 38000, Grenoble, France), M. Magliocchetti (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), C. Mancini (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), R. Maoli (Dipartimento di Fisica, Sapienza Universit\`a di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy, INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), C. J. A. P. Martins (Centro de Astrof\'isica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal), L. Maurin (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), M. Miluzio (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain, HE Space for European Space Agency), P. Monaco (Dipartimento di Fisica - Sezione di Astronomia, Universit\`a di Trieste, Via Tiepolo 11, 34131 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy), C. Moretti (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy), G. Morgante (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Nadathur (Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK), K. Naidoo (Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK), P. Natoli (Dipartimento di Fisica e Scienze della Terra, Universit\`a degli Studi di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), A. Navarro-Alsina (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), S. Nesseris (Instituto de F\'isica Te\'orica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain), D. Paoletti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), F. Passalacqua (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), K. Paterson (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), L. Patrizii (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), A. Pisani (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), D. Potter (Department of Astrophysics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland), S. Quai (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), M. Radovich (INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), P. -F. Rocci (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), G. Rodighiero (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), S. Sacquegna (INAF - Osservatorio Astronomico d'Abruzzo, Via Maggini, 64100, Teramo, Italy, Department of Mathematics and Physics E. De Giorgi, University of Salento, Via per Arnesano, CP-I93, 73100, Lecce, Italy, INFN, Sezione di Lecce, Via per Arnesano, CP-193, 73100, Lecce, Italy), M. Sahl\'en (Theoretical astrophysics, Department of Physics and Astronomy, Uppsala University, Box 516, 751 37 Uppsala, Sweden), D. B. Sanders (Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA), E. Sarpa (SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy, ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing, Via Magnanelli 2, Bologna, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy), C. Scarlata (Minnesota Institute for Astrophysics, University of Minnesota, 116 Church St SE, Minneapolis, MN 55455, USA), A. Schneider (Department of Astrophysics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland), D. Sciotti (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy, INFN-Sezione di Roma, Piazzale Aldo Moro, 2 - c/o Dipartimento di Fisica, Edificio G. Marconi, 00185 Roma, Italy), E. Sellentin (Mathematical Institute, University of Leiden, Einsteinweg 55, 2333 CA Leiden, The Netherlands, Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), F. Shankar (School of Physics \& Astronomy, University of Southampton, Highfield Campus, Southampton SO17 1BJ, UK), L. C. Smith (Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK), E. Soubrie (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), K. Tanidis (Department of Physics, Oxford University, Keble Road, Oxford OX1 3RH, UK), C. Tao (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), G. Testera (INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy), R. Teyssier (Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544, USA), S. Tosi (Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), A. Troja (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), M. Tucci (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), C. Valieri (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), A. Venhola (Space physics and astronomy research unit, University of Oulu, Pentti Kaiteran katu 1, FI-90014 Oulu, Finland), G. Verza (Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, 10010, New York, NY, USA), P. Vielzeuf (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), A. Viitanen (Department of Physics and Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland, Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland, INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), N. A. Walton (Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK), J. R. Weaver (Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA) - - - FIRESTORM I: Stellar Feedback and Gas Kinematics in the Evolved W40 Hub-Filament System - https://arxiv.org/abs/2512.08811 - arXiv:2512.08811v1 Announce Type: new -Abstract: The FIRESTORM project--Feedback-Induced Regions and Emission from Star-forming Tracers of ObseRvable Molecular Gas--has targeted four star-forming regions to quantify the impact of stellar feedback on star formation. In this paper, we present multiwavelength results for one of the targets, the nearby high-mass star-forming region W40. Using dense-gas tracers C$^{18}$O(1--0) and H$^{13}$CO$^+$(1--0), we identified six velocity-coherent filaments: five at \vlsr $\sim$\,7.5\kms\! and one at \vlsr $\sim$\,5\kms. Four of these converge towards an infrared-bright cluster hosting the most massive star of the region (IRS 1A South, O9.5V), forming a hub-filament system (HFS). Key physical parameters, including filament lengths, widths, masses, velocity dispersions, and line masses, are derived. Five dense clumps traced by N$_2$H$^+$(1--0) exhibit subsonic to transonic turbulence, contrasting with the supersonic motions of their parental filaments, indicating turbulence dissipation. A deficit of emission at \vlsr $\sim$\,7\kms\! in several molecular lines, along with a blueshifted absorption dip in the HCN(1--0) profile, suggests that emission from OB-heated gas is being absorbed by a cold foreground cloud. A bridge-like feature in position-velocity space connects the \vlsr $\sim$\,5 and $\sim$\,7.5\kms\! filaments, and spatially coinciding with dense condensations and radio continuum peaks. These findings suggest that a past interaction--likely a cloud-cloud collision--triggered the formation of HFS and ultimately the central massive cluster. - oai:arXiv.org:2512.08811v1 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ming-Kang Lim (National Astronomical Research Institute of Thailand), Ram K. Yadav (National Astronomical Research Institute of Thailand), L. K. Dewangan (Physical Research Laboratory, Navrangpura, Ahmedabad - 380 009, India), Kee-Tae Kim (Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea), A. Zavagno (Aix-Marseille Universite, CNRS, CNES, LAM, Marseille, France), Jedsada Maklai (National Astronomical Research Institute of Thailand), Nicola Schneider (I. Physikalisches Institut, Universit\"at zu K\"oln, Z\"ulpicher Str. 77, 50937 K\"oln, Germany), D. Arzoumanian (The Institute for Advanced Study, Kyushu University), Arshia M. Jacob (I. Physikalisches Institut, Universit\"at zu K\"oln, Z\"ulpicher Str. 77, 50937 K\"oln, Germany), L. E. Pirogov (Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov st., Nizhny Novgorod 603950, Russia), Jihye Hwang (The Institute for Advanced Study, Kyushu University), D. K. Ojha (Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India), Gyuho Lee (Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea), Affan Adly Nazri (Radio Cosmology Research Laboratory, Center for Astronomy and Astrophysics Research, Department of Physics, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia), Saurabh Sharma (Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263002, India) - - - Probing the environment around GW170817 with DESI: insights on galaxy group peculiar velocities for standard siren measurements - https://arxiv.org/abs/2512.08818 - arXiv:2512.08818v1 Announce Type: new -Abstract: We present a new measurement of the Hubble constant, $H_0$, following the gravitational wave event GW170817 and Dark Energy Spectroscopic Instrument (DESI) observations. A standard siren measurement with a nearby (luminosity distance $\sim 40 $ Mpc) event such as GW170817 is typically sensitive to the peculiar motion of the host galaxy due to local dynamics. Previous measurements from this event have taken advantage of peculiar velocity measurements of nearby galaxies, including a handful of objects in the galaxy group that the host of the event, NGC 4993, has been associated with. Still, the group's properties and NGC 4993's membership were debated. We present DESI observations of thousands of galaxies in the vicinity of NGC 4993, resulting in 39 group galaxies and a five-fold increase in galaxies compared to previous observations with many of these galaxies contributing to a peculiar velocity measurement. Examining the local dynamics, our observations support the presence of a galaxy group of which NGC 4993 is part with a halo mass of order $\sim$$10^{13}~M_\odot$. Using peculiar velocity measurements from our Fundamental Plane galaxies observations, we find $H_0 =70.9^{+6.4}_{-8.5}$ km s$^{-1}$ Mpc$^{-1}$. In addition, using a peculiar velocity measurement for NGC 4993 from Surface Brightness Fluctuations in Cosmicflows-4 we find $H_0 =73.4^{+3.3}_{-3.9}$ km s$^{-1}$ Mpc$^{-1}$. We study the impact of different galaxy selection criteria on the determination of the peculiar velocity and, in turn, on the $H_0$ measurement. Our results highlight the importance of multiplexed spectroscopic observations of the environments of gravitational wave events to probe local dynamics, which can ultimately affect standard siren measurements. - oai:arXiv.org:2512.08818v1 - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - A. J. Amsellem, A. Palmese, K. Douglass, C. Howlett, Juliana S. M. Karp, I. Maga\~na Hernandez, J. Moustakas, R. H. Wechsler, J. Aguilar, S. Ahlen, S. Benzvi, D. Bianchi, D. Brooks, A. Carr, T. Claybaugh, A. Cuceu, Tamara M. Davis, A. de la Macorra, Arjun Dey, Biprateep Dey, P. Doel, A. Font-Ribera, J. E. Forero-Romero, E. Gazta\~naga, S. Gontcho A Gontcho, G. Gutierrez, K. Honscheid, M. Ishak, R. Joyce, R. Kehoe, T. Kisner, A. Kremin, O. Lahav, A. Lambert, M. Landriau, L. Le Guillou, M. Manera, V. Manwadkar, A. Meisner, R. Miquel, A. D. Myers, S. Nadathur, G. Niz, N. Palanque-Delabrouille, W. J. Percival, C. Poppett, F. Prada, I. P\'erez-R\`afols, A. Raichoor, G. Rossi, E. Sanchez, D. Schlegel, M. Schubnell, H. Seo, J. Silber, D. Sprayberry, G. Tarl\'e, R. Zhou, the DESI Collaboration - - - Exploring the binary origin of B and Be rapid rotators - https://arxiv.org/abs/2512.08821 - arXiv:2512.08821v1 Announce Type: new -Abstract: Observational evidence has continued to mount that a significant fraction of rapidly rotating early-B type stars are products of binary mass transfer. However, very few mid- and late-type B stars with rapid rotation have been demonstrated to be post-interaction products, despite a growing sample of SB1 binaries among stars within this range of spectral types. By considering the currently available information over the entire range of rapidly rotating B-type binaries, we argue that a significant fraction of the mid- and late-type rapid rotators found in binaries are also likely the result of past mass transfer episodes. The observed properties of this sample are compared to the predictions from the Binary Population and Spectral Synthesis code (BPASS), with attention given to the expected evolutionary pathways of stripped stars and the stellar and binary properties of both components of post-interaction systems across a range of initial conditions. Prospects for directly detecting and characterizing the stripped cores of the previous mass donors in such systems are described, and the implications for the role of binary interaction in causing rapid rotation are discussed. An accurate description of prevalence of binary interaction, the physics of mass transfer, and the post-interaction configuration of systems over a range of initial conditions has far-reaching implications including double-degenerate binaries and their eventual mergers, the output of ionizing UV flux of stellar populations, and the supernova explosions that can arise from stripped or rapidly-rotating progenitors. - oai:arXiv.org:2512.08821v1 - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Jonathan Labadie-Bartz, Mark Suffak, Carol Jones, Ya\"el Naz\'e, Ken Gayley, Geraldine Peters, Rina Rast, Anusha Ravikumar, Asif ud-Doula, Coralie Neiner, Jeremy J. Drake + Tianyi Yang, Ian G. McCarthy, Fiona McCarthy, Boris Bolliet, Jens Chluba, William Coulton, John C. Helly, Matthieu Schaller, Joop Schaye - A search for successful and choked jets in nearby broad-lined Type Ic supernovae - https://arxiv.org/abs/2512.08822 - arXiv:2512.08822v1 Announce Type: new -Abstract: The observational link between long gamma-ray bursts (GRBs) and broad-lined stripped-envelope core-collapse supernovae (SNe Ic-BL) is well established. Significant progress has been made in constraining what fraction of SNe Ic-BL may power high- or low-luminosity GRBs when viewed at small off-axis angles. However, the GRB-SN connection still lacks a complete understanding in the broader context of massive-star evolution and explosion physics. Models predict a continuum of outcomes for the fastest ejecta, from choked to ultra-relativistic jets, and observations from radio to X-rays are key to probing these scenarios across a range of viewing angles and velocities. Here, we present results from a coordinated radio-to-X-ray campaign targeting nearby (z<=0.1) SNe Ic-BL designed to explore this diversity. With eight new radio-monitored events and updated data for one previously observed SN, we further tighten constraints on the fraction of SNe Ic-BL as relativistic as SN 1998bw/GRB 980425. We identify SN 2024rjw as a new radio-loud event likely powered by strong interaction with circumstellar material (CSM), and add evidence supporting a similar interpretation for SN 2020jqm. We also establish new limits on the properties of radio-emitting ejecta with velocities consistent with cocoons from choked jets, highlighting SN 2022xxf as a promising cocoon-dominated candidate. These results refine our understanding of the continuum linking ordinary SNe Ic-BL, engine-driven explosions, and GRBs, and contribute to building a sample that will inform future multi-messenger searches for electromagnetic counterparts to high-energy neutrinos. - oai:arXiv.org:2512.08822v1 - astro-ph.HE + Self-calibration of weak lensing cosmic shear biases + https://arxiv.org/abs/2512.09922 + arXiv:2512.09922v1 Announce Type: new +Abstract: In order to reach the required performance of Stage-III and IV weak lensing surveys, cosmic shear measurements have to rely on external simulations to calibrate residual biases. Over the years, several techniques have been developed to mitigate the impact of residual biases prior to calibration, including the inference of shear responses on images to correct multiplicative biases, and the empirical correction of additive biases. We introduce a novel methodology that generalises upon the state-of-the-art approaches by inferring multiplicative and additive biases jointly from parameterised distributions of measured ellipticities, crucially without relying on external simulations and independently from cosmology. Shear biases are marginalised over the unknown hyper-parameters in the modelling, hence mitigating the impact of degeneracies. We apply the technique to a representative problem and show the performance of the estimation, even in the presence of noise. The method has a high potential for applicability to the calibration of weak lensing cosmic shear in current and future lensing surveys. + oai:arXiv.org:2512.09922v1 astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Tanner O'Dwyer, Alessandra Corsi, Sheng Yang, Shreya Anand, S. Bradley Cenko, Gokul P. Srinivasaragavan, Anna Y. Q. Ho, Jesper Sollerman, Bei Zhou, Arvind Balasubramanian, Po-Wen Chang, Marc Kamionkowski, Daniel Perley, Russ R. Laher, Kohta Murase, Frank J. Masci, Mansi M. Kasliwal, Josiah N. Purdum, Matthew J. Graham - - - Near-IR CO and CN in classical Cepheids - https://arxiv.org/abs/2512.08831 - arXiv:2512.08831v1 Announce Type: new -Abstract: We present medium resolution near-infrared spectral measurements of the carbon monoxide (CO) and the cyano radical (CN) features in 12 Galactic classical Cepheids. The pulsation periods of our sample range from 5.5 to 69 days, and the stars studied each had five or more near-IR spectral observations. The CO and CN measurements were used to probe CNO abundances of these stars, and elemental abundance values from the literature were used to identify the trends of [C/N] and [O/N] with CN and CO. To put these measurements in context, we performed stellar atmosphere fitting to obtain estimates of stellar parameters, with a primary focus on effective temperature. Our measurements and temperature estimates show that CN is significantly affected by dredge-up of processed material. We provide discussion as to the potential nature of the recently confirmed classical Cepheid, ET~Vul, and connect our near-infrared CO measurements to the mid-infrared period-colour-metallicity relation. - oai:arXiv.org:2512.08831v1 - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Scott G. Call, Thomas Griffith, Eric G. Hintz, Steve Ardern, Victoria Scowcroft, Jared Davidson, Benjamin Boizelle - - - Self-lensing of moving gravitational-wave sources can break the microlensing crossing timescale degeneracy - https://arxiv.org/abs/2512.08898 - arXiv:2512.08898v1 Announce Type: new -Abstract: When a moving gravitational-wave (GW) source travels behind a massive astrophysical object, its signal is gravitationally lensed, showing a waveform distortion similar to a Paczy\'{n}ski curve. We present a first study of the lensing signature of a massive black hole (MBH) on a frequency-dependent GW signal from a moving binary merger. For both light and GW sources in a Keplerian circular orbit around a MBH lens, the self-lensing geometry breaks the microlensing degeneracy in the Einstein radius crossing timescale $t_{\rm E}$. The duration of the curve ($2 t_{\rm E}$) becomes independent on the MBH mass $M_{\rm MBH}$, and provides a direct measure of the distance $d_{\rm LS}$ to the MBH. However, $M_{\rm MBH}$ remains unknown. We show that, in GW signals, the redshifted mass $M_{{\rm MBH},z}$ can additionally be obtained from the interference pattern, by measuring the modulation period $T$, the GW frequency $f$, and $t_{\rm E}$: $M_{{\rm MBH},z}\simeq 2.5\times 10^6\,M_\odot\,(t_{\rm E}/[100\,{\rm s}])\,(f\,T)^{-1}$. If this lensing signature is not considered, it may be confused with other waveform distortions, especially in the modeling of overlapping signals in next generation ground-based GW detectors. The observation of one of these curves and its associated parameters may help (1) constrain the orbital distance $d_{\rm LS}$ of sources, especially around low mass MBHs at the centers of star clusters and galaxies, (2) additionally estimate the mass $M_{{\rm MBH},z}$ of these MBHs, and (3) infer the orbital inclination of the binary. Simultaneously obtaining $d_{\rm LS}$ and $M_{{\rm MBH},z}$ through self-lensing can help constrain the astrophysical environments where GW signals come from. - oai:arXiv.org:2512.08898v1 - astro-ph.HE - astro-ph.CO - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Helena Ubach - - - The impact of lunar topography on the 21-cm power spectrum for grid-based arrays : Insights for the Dark-ages EXplorer (DEX) - https://arxiv.org/abs/2512.08906 - arXiv:2512.08906v1 Announce Type: new -Abstract: The Dark Ages (DA) provides a crucial window into the physics of the infant Universe, with the 21-cm signal offering the only direct probe for mapping out the three-dimensional distribution of matter at this epoch. To measure this cosmological signal, the Dark-ages EXplorer (DEX) has been proposed as a compact, grid-based radio array on the lunar farside. The minimal design consists of a 32 $\times$ 32 array of 3-m dipole antennas, operating in the $7 - 50$ MHz band. A practical challenge on the lunar surface is that the antennas may get displaced from their intended positions due to deployment imprecisions and non-coplanarity arising from local surface undulations. We present, for the first time, an end-to-end simulation pipeline, called SPADE-21cm, that integrates a sky model with a DA 21-cm signal model simulated in the lunar frame and incorporating lunar topography data. We study the effects of both lateral (xy) and vertical (z) offsets on the two-dimensional power spectra across the $7 - 12$ MHz and $30 - 35$ MHz spectral windows, with tolerance thresholds derived only for the latter. Our results show that positional offsets bias the power spectrum by $10 - 30$ per cent relative to the expected 21-cm power spectrum during DA. Lateral offsets within $\sigma_{xy}/\lambda \lesssim 0.027$ (at 32.5 MHz) keep the fraction of Fourier modes with strong contamination (> 50 per cent of the signal) to less than 1 per cent, whereas vertical height offsets affect a larger fraction. This conclusion holds for the 21-cm window with $k_\parallel > 0.5$ $h$ cMpc$^{-1}$ over the range of $k_\perp = 0.003 - 0.009$ $h$ cMpc$^{-1}$. - oai:arXiv.org:2512.08906v1 astro-ph.IM - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - S. Ghosh, L. V. E. Koopmans, C. Brinkerink, A. R. Offringa, A. J. Boonstra, S. A. Brackenhoff, E. Ceccotti, J. K. Chege, L. Y. Gao, B. K. Gehlot, L. I. Gurvits, C. H\"ofer, F. G. Mertens, M. Mevius, S. Munshi, A. Saxena, J. A. Tauber, H. Vedantham, S. Yatawatta, S. Zaroubi - - - Foreground Mitigation for CMB Lensing with the Global Minimum Variance Quadratic Estimator - https://arxiv.org/abs/2512.08908 - arXiv:2512.08908v1 Announce Type: new -Abstract: Weak gravitational lensing of the cosmic microwave background (CMB) is a powerful probe of cosmology, providing insight into structure formation and the evolution of the universe. Current and upcoming CMB experiments such as SPT-3G and the Simons Observatory (SO) provide high-resolution, low-noise temperature and polarization maps that are ideal for lensing reconstruction. The global minimum variance (GMV) quadratic estimator for CMB lensing reduces reconstruction noise over the standard quadratic estimator (SQE). In this work, we extend the GMV framework to incorporate the tSZ-deproj and cross-ILC foreground mitigation techniques, which enhance robustness against contamination from astrophysical sources. For SPT-3G Ext-10k and SO Extended at $\ell_{\mathrm{max}}^T = 3500$, the lensing bias at $L < 1000$ is reduced from $\sim4\%$ with standard GMV and SQE to $2\%$ with tSZ-deproj, and to $< 1\%$ with cross-ILC. These methods enable the construction of foreground-cleaned lensing maps suitable for cross-correlation analyses, with direct relevance for current and future surveys. - oai:arXiv.org:2512.08908v1 - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yuka Nakato, W. L. Kimmy Wu, Ana Carolina Silva Oliveira, Yuuki Omori, Abhishek S. Maniyar - - - Resolving the (Debate About) Nozzle Shocks in Tidal Disruption Events - https://arxiv.org/abs/2512.08928 - arXiv:2512.08928v1 Announce Type: new -Abstract: When a star passes within the Roche limit of a supermassive black hole (SMBH), it is pulled apart by the BH's tidal field in a tidal disruption event (TDE). The resulting flare is powered by the circularization and accretion of bound stellar debris, which initially returns to the BH on eccentric orbits in a thin debris stream. The returning fluid elements follow inclined orbits that converge near pericenter, resulting in extreme vertical compression to scales $10^{-4}~R_\odot$ and the formation of a nozzle shock. Dissipation at the nozzle shock may affect circularization by altering the properties of the debris stream, but its role is the subject of ongoing debate. We develop an idealized model for the debris stream evolution combining 3D smoothed-particle hydrodynamics simulations, the semi-analytic affine model, and 1D finite-volume hydrodynamic simulations. Because our model is computationally cheap, we can unambiguously resolve the nozzle shock, use a realistic equation of state, and follow the debris stream evolution at many different times. Near peak fallback, Hydrogen recombination and molecular Hydrogen formation broaden the stream by a factor $\sim 5$, enhancing dissipation at the nozzle. However, the dissipation is still insufficient to directly circularize the debris by in-plane pressure gradients. Instead, the thicker stream substantially increases the likelihood that the stream self-intersects on the second orbit, despite relativistic nodal precession. The stream properties at self-intersection are sensitive to dissipation at the nozzle and the timing of focal points where the ballistic trajectories of the debris converge. Our results clarify the nozzle shock's role in circularization in TDEs, providing a foundation for more realistic circularization and emission models. - oai:arXiv.org:2512.08928v1 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Zachary L. Andalman, Eliot Quataert, Eric R. Coughlin, C. J. Nixon + G. Congedo, A. N. Taylor - Hot Jupiters are Inflated Primarily by Shallow Heating - https://arxiv.org/abs/2512.08932 - arXiv:2512.08932v1 Announce Type: new -Abstract: The unexpectedly large radii of transiting hot Jupiters have led to many proposals for the physical mechanisms responsible for heating their interiors. While it has been shown that hot Jupiters reinflate as their host stars brighten due to heating deep in planetary interiors, young hot Jupiters also exhibit signs of delayed cooling possibly related to heating closer to their surfaces. To investigate this tension, we enhance our previously published hot Jupiter thermal evolution model by adding a parameter that allows for both deep heating and delayed cooling. We fit our thermal evolution models to a homogeneous, physically self-consistent catalog of accurate and precise hot Jupiter system properties in a hierarchical Bayesian framework. We find that hot Jupiters' interior cooling rates are reduced on average by 95\%--98\% compared to simpler anomalous heating models. The most plausible explanation for this inference is substantial shallow heating just below their radiative--convective boundaries that enables reinflation with much less deep heating. Shallow heating by Ohmic dissipation and/or temperature advection are therefore important components of accurate models of hot Jupiter atmospheres, especially in circulation models. If hot Jupiters are inflated primarily by shallow heating as we propose, then we predict that their observed phase curve offsets should increase with temperature in the range $T_{\text{eq}}~\lesssim1500~\text{K}$, peak in the range $1500~\text{K}~\lesssim~T_{\text{eq}}~\lesssim~1800~\text{K}$, and decrease in the range $T_{\text{eq}}~\gtrsim~1800~\text{K}$. - oai:arXiv.org:2512.08932v1 - astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Stephen P. Schmidt, Daniel P. Thorngren, Kevin C. Schlaufman - - - Core-halo scaling relations in self-interacting scalar field dark matter - https://arxiv.org/abs/2512.07020 - arXiv:2512.07020v1 Announce Type: cross -Abstract: We study the impact of self-interactions on the structure and evolution of scalar field dark matter (SFDM) halos. Using three-dimensional Gross-Pitaevskii-Poisson simulations of multiple soliton mergers, we explore both repulsive and attractive regimes across a wide range of scattering lengths. Our results show that repulsive self-interactions lead to more massive and extended cores with lower central densities compared to the free (non-interacting) fuzzy dark matter case, while attractive interactions enhance central densities and can drive cores toward collapse, once a critical mass is exceeded. We confirm that the mass-radius relation of solitonic cores is well described by analytical predictions, even in the presence of self-interactions, and we extend the core-halo mass relation to scenarios beyond fuzzy dark matter. We find that the scaling relations between core mass, size, and total energy are not universal but depend sensitively on the strength and sign of the self-interaction, as well as on the evolutionary stage of the halo. These results demonstrate that self-interactions provide a natural mechanism to regulate core properties, with important implications for the formation of supermassive black holes and for potential astrophysical signatures in galactic cores. - oai:arXiv.org:2512.07020v1 - astro-ph.CO + Centrally concentrated star formation in young clusters + https://arxiv.org/abs/2507.05016 + arXiv:2507.05016v2 Announce Type: cross +Abstract: The study of star cluster evolution necessitates modeling how their density profiles develop from their natal gas distribution. Observational evidence indicates that many star clusters follow a Plummer-like density profile. However, most studies have focused on the phase after gas ejection, neglecting the influence of gas on early dynamical evolution. We investigate the development of star clusters forming within gas clouds, particularly those with a centrally concentrated gas profile. Simulations were conducted using the \texttt{Torch} framework, integrating the \texttt{FLASH} magnetohydrodynamics code into \texttt{AMUSE}. This permits detailed modeling of star formation, stellar evolution, stellar dynamics, radiative transfer, and gas magnetohydrodynamics. We study the collapse of centrally concentrated, turbulent spheres with a total mass of $2.5\times 10^3\, M_\odot$, investigating the effects of varying numerical resolution and star formation scenarios. The free-fall time is shorter at the center than at the edges of the cloud, with a minimum value of $0.55\,\mathrm{Myr}$. The key conclusions from this study are: (1) the final stellar density profile is more centrally concentrated than analytically predicted, reflecting the role of global gas collapse and feedback; (2) sub-clusters can initially form even in centrally concentrated gas clouds; (3) gas collapses globally toward the center on the central free-fall time scale, contradicting the assumption in analytical models of local fragmentation and star formation; and (4) the mass of the most massive star formed is directly correlated with the cluster effective radius and inversely correlated with the velocity dispersion, while the duration of star formation correlates with the star formation efficiency. + oai:arXiv.org:2507.05016v2 astro-ph.GA - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Jessica N. L\'opez-S\'anchez, Erick Munive-Villa, Tanja Rindler-Daller + Adilkhan Assilkhan, Mordecai-Mark Mac Low, Brooke Polak, Ernazar Abdikamalov, Claude Cournoyer-Cloutier, Sean C. Lewis, Mukhagali Kalambay, Aigerim Otebay, Bekdaulet Shukirgaliyev - Impact on orbital period of X-ray Binary system attached to a cosmic string - https://arxiv.org/abs/2512.07911 - arXiv:2512.07911v1 Announce Type: cross -Abstract: Cosmic strings attached to rotating black holes extract its rotational energy, resulting in a mass loss and reduced spin. In this paper we discuss the proposed methods to detect these phenomena and present a novel methodology based on existing literature, by considering a Low Mass X-ray binary system. We investigate the impact of a cosmic string interacting with a black hole in an X-ray binary system and attempt to explain the observations of unexpected orbital period changes in such systems by proposing mass loss by cosmic strings to be a potential cause. For a period change of order $10^{-10}$, the string tension is $\sim 10^{-17}$, lying in the predicted range for cosmic string tension. An analysis of multiple low mass X-ray binary systems is carried out and it is shown that a significant and observable change occurs for a string tension $\sim 10^{-11}$. - oai:arXiv.org:2512.07911v1 + Quasinormal ringing of Kerr black holes. III. Excitation coefficients for equatorial inspirals from the innermost stable circular orbit + https://arxiv.org/abs/2512.07959 + arXiv:2512.07959v1 Announce Type: cross +Abstract: The remnant of a black hole binary merger settles into a stationary configuration by "ringing down" through the emission of gravitational waves that consist of a superposition of damped exponentials with discrete complex frequencies - the remnant black hole's quasinormal modes. While the frequencies themselves depend solely on the mass and spin of the remnant, the mode amplitudes depend on the merger dynamics. We investigate quasinormal mode excitation by a point particle plunging from the innermost stable circular orbit of a Kerr black hole. Our formalism is general, but we focus on computing the quasinormal mode excitation coefficients in the frequency domain for equatorial orbits, and we analyze their dependence on the remnant black hole spin. We find that higher overtones and subdominant multipoles of the radiation become increasingly significant for rapidly rotating black holes. This suggests that the prospects for detecting overtones and higher-order modes are considerably enhanced for highly spinning merger remnants. + oai:arXiv.org:2512.07959v1 gr-qc astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 cross - http://creativecommons.org/licenses/by/4.0/ - 10.1016/j.newast.2025.102378 - Journal = New Astronomy Volume = 118 Pages = 102378 Year = 2025 ISSN = 1384-1076 - Ishan Swamy, Deobrat Singh + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Matteo Della Rocca, Laura Pezzella, Emanuele Berti, Leonardo Gualtieri, Andrea Maselli - Infrared Freeze-In of Magnetic Dipole Dark Matter - https://arxiv.org/abs/2512.07927 - arXiv:2512.07927v1 Announce Type: cross -Abstract: We propose a novel mechanism for the cosmological production of keV - GeV mass dark matter that interacts with the Standard Model through a small effective magnetic dipole moment. Such an interaction can be radiatively generated if dark matter couples to heavier charged particles. Previous studies have focused on the case where these charged states are much heavier than the reheat temperature, such that freeze-in production of dark matter is sensitive to the ultraviolet details of reheating. Here, we instead consider the possibility that these heavy states have masses comparable to the dark matter mass and are charged under a new kinetically-mixed $U(1)'$. As a result, dark matter production is dominated by the infrared freeze-in of the heavy charged states that subsequently thermalize the rest of the dark sector to a temperature much below that of the visible bath. We delineate regions of parameter space consistent with cosmological and astrophysical constraints and identify benchmark scenarios that can guide the next generation of direct detection experiments searching for spin-dependent scattering of sub-GeV dark matter. - oai:arXiv.org:2512.07927v1 + Search for Dark Matter Annihilation and Decay with H$\alpha$ Line Emission + https://arxiv.org/abs/2512.09019 + arXiv:2512.09019v1 Announce Type: cross +Abstract: I present a new indirect search for dark matter (DM) using Hydrogen-$\alpha$ (H$\alpha$) recombination emission. DM annihilation or decay products can ionize neutral gas; subsequent recombination cascades generate H$\alpha$ photons through the $3\rightarrow2$ transition. In quiet gas-rich dwarf galaxies, the $n{=}2$ population is negligible, so H$\alpha$ is effectively unabsorbed and traces the DM-energy injection site. Using the non-detection of extended H$\alpha$ emission in the Leo T dwarf galaxy with Multi Unit Spectroscopic Explorer (MUSE) observations, I derive the first H$\alpha$-based limits on DM annihilation and decay, reaching leading sensitivity for parts of the eV-GeV mass range. Existing and upcoming telescopes can further extend this reach, establishing H$\alpha$ imaging as a powerful DM search strategy. + oai:arXiv.org:2512.09019v1 hep-ph - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.GA + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Asher Berlin, Jae Hyeok Chang, Tanner Trickle + Rebecca K. Leane - Inflationary Particle Production and the Swampland - https://arxiv.org/abs/2512.07930 - arXiv:2512.07930v1 Announce Type: cross -Abstract: We investigate the impact of particle production during inflation in scenarios where an infinite tower of states features a mass scale that decreases exponentially along the inflationary trajectory. Such couplings naturally arise in string effective field theories and are in fact motivated by the Swampland Distance Conjecture (SDC). We show that the corrections to inflationary observables sourced by the tower scale as $(H/\Lambda_{\text{sp}})^{2+p}$, with $H$ being the Hubble scale, $\Lambda_{\text{sp}}$ being the species scale, that is the quantum gravity cut-off, and $p\geq 1$ characterizes the density of states in the tower. As a result, in gravitationally weakly coupled cosmological effective theories, the tower-induced contributions are suppressed relative to the standard single-field predictions, leaving the inflationary phenomenology essentially unchanged. We demonstrate this explicitly across a set of well-motivated inflationary potentials, and we compare the resulting predictions with the most recent observational constraints, including those from the Atacama Cosmology Telescope. - oai:arXiv.org:2512.07930v1 - hep-th + Curvaton-assisted hilltop inflation + https://arxiv.org/abs/2512.09079 + arXiv:2512.09079v1 Announce Type: cross +Abstract: Following the recent Atacama Cosmology Telescope (ACT) results, we consider hilltop inflation where the inflaton is coupled to a curvaton, simultaneously addressing two main challenges faced by conventional hilltop inflation models: the initial-value problem; and their viability for sub-Planckian field values. In standard single-field hilltop inflation, the inflaton must start extremely close to the maximum of the potential, raising concerns about the naturalness of the initial conditions. We demonstrate that the curvaton field not only solves the initial-value problem, but also opens up parameter space through modifying the curvature perturbation power spectrum, reviving the cubic and quartic hilltop inflation models in the sub-Planckian regime. We find viable parameter space consistent with the recent cosmological observations, and predict a sizable tensor-to-scalar ratio that can be tested in the next-generation Cosmic Microwave Background (CMB) experiments. + oai:arXiv.org:2512.09079v1 + hep-ph astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Dieter L\"ust, Joaquin Masias, Mauro Pieroni, Marco Scalisi + Wen-Yuan Ai, Stephen F. King, Xin Wang, Ye-Ling Zhou - Open Effective Field Theory and the Physics of Cosmological Collider Signals - https://arxiv.org/abs/2512.07941 - arXiv:2512.07941v1 Announce Type: cross -Abstract: We examine the origin of the cosmological collider signal using the framework of open effective field theories. Focusing on the single exchange of a massive scalar field, we demonstrate that the trispectrum splits cleanly into its local and non-local components once the heavy-field propagators are decomposed in the Keldysh basis. Integrating out the massive degree of freedom yields a single-field effective field theory for the light scalar that necessarily contains both unitary operators and non-unitary contributions associated with dissipation and stochastic noise. We show that the leading local signal in parity-preserving theories arises from the unitary part of this effective field theory, whereas the non-local signal is intrinsically associated with its stochastic sector. The effective field theory coefficients themselves are a priori non-analytic in the external kinematics; however, this non-analyticity can be softened when a scale hierarchy - such as the heavy-mass expansion - is imposed, up to spurious contributions that ultimately cancel in observables. Finally, we establish a connection between the cosmological collider signal and entropy production, linking the observable non-local signal to intrinsic properties of the quantum state, including its degree of mixedness. - oai:arXiv.org:2512.07941v1 - hep-th - astro-ph.CO - gr-qc - hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 + High Order Numerical Methods Preserving Invariant Domain for Hyperbolic and Related Systems + https://arxiv.org/abs/2512.09116 + arXiv:2512.09116v1 Announce Type: cross +Abstract: Admissible states in hyperbolic systems and related equations often form a convex invariant domain. Numerical violations of this domain can lead to loss of hyperbolicity, resulting in illposedness and severe numerical instabilities. It is therefore crucial for numerical schemes to preserve the invariant domain to ensure both physically meaningful solutions and robust computations. For complex systems, constructing invariant-domain-preserving (IDP) schemes is highly nontrivial and particularly challenging for high-order accurate methods. This paper presents a comprehensive survey of IDP schemes for hyperbolic and related systems, with a focus on the most popular approaches for constructing provable IDP schemes. We first give a systematic review of the fundamental approaches for establishing the IDP property in first-order accurate schemes, covering finite difference, finite volume, finite element, and residual distribution methods. Then we focus on two widely used and actively developed classes of high order IDP schemes as well as their recent developments, most of which have emerged in the past decade. The first class of methods seeks an intrinsic weak IDP property in high-order schemes and then designs polynomial limiters to enforce a strong IDP property at the points of interest. This generic approach applies to high-order finite volume and discontinuousGalerkin schemes. The second class is based on the flux limiting approaches, which originated from the flux-corrected transport method and can be adapted to a broader range of spatial discretizations, including finite difference and continuous finite element methods. In this survey, we elucidate the main ideas in the construction of IDP schemes, provide some new perspectives and insights, with extensive examples, and numerical experiments in gas dynamics and magnetohydrodynamics. + oai:arXiv.org:2512.09116v1 + math.NA + astro-ph.IM + cs.NA + physics.comp-ph + physics.flu-dyn + Thu, 11 Dec 2025 00:00:00 -0500 cross - http://creativecommons.org/licenses/by/4.0/ - Thomas Colas, Zhehan Qin, Xi Tong + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Kailiang Wu, Xiangxiong Zhang, Chi-Wang Shu - Rapidly Spinning Massive Pulsars as an Indicator of Quark Deconfinement - https://arxiv.org/abs/2512.07977 - arXiv:2512.07977v1 Announce Type: cross -Abstract: We study rotating hybrid stars, with particular emphasis on the effect of spin on the deconfinement phase transition and star properties. Our analysis is based on a hybrid equation of state with a phase transition from hadronic matter containing hyperons to color-superconducting quark matter, where the quark phase is modeled within a relativistic density functional approach. By varying the strength of the vector repulsion and diquark pairing couplings in the microscopic quark Lagrangian, we construct a set of hybrid star sequences with different quark-matter onset densities. This framework ensures consistency with astrophysical and gravitational wave constraints on mass, radius, and tidal deformability. - oai:arXiv.org:2512.07977v1 - nucl-th - astro-ph.HE + Primordial magnetic field from chiral plasma instability with sourcing + https://arxiv.org/abs/2512.09177 + arXiv:2512.09177v1 Announce Type: cross +Abstract: In an electron-positron plasma, an imbalance in the number of right- and left-chiral particles can lead to the growth of a helical magnetic field through a phenomenon called the chiral plasma instability (CPI). In the early universe, scattering reactions that violate chirality come into thermal equilibrium when the plasma cools below a temperature of approximately $80 \, \mathrm{TeV}$. Since these reactions tend to relax any pre-existing chiral asymmetry to zero as the system approaches equilibrium, the standard lore is that primordial magnetogenesis via the CPI is not viable below $80 \, \mathrm{TeV}$. In this work, we propose that the presence of a source for chirality can allow the CPI to operate even below $80 \, \mathrm{TeV}$, we explore the implications of this scenario, and we derive predictions for the resultant magnetic field helicity using a combination of analytical methods and direct numerical simulation. + oai:arXiv.org:2512.09177v1 hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - 10.1103/PhysRevD.111.123021 - Phys.Rev.D 111 (2025) 12 - Christoph G\"artlein, Violetta Sagun, Oleksii Ivanytskyi, David Blaschke, Il\'idio Lopes + http://creativecommons.org/licenses/by/4.0/ + Murman Gurgenidze, Andrew J. Long, Alberto Roper Pol, Axel Brandenburg, Tina Kahniashvili - Noble gravitational atoms: Self-gravitating black hole scalar wigs with angular momentum number - https://arxiv.org/abs/2512.08095 - arXiv:2512.08095v1 Announce Type: cross -Abstract: We present new spherically symmetric solutions of the Einstein-Klein-Gordon equations in a quasi-stationary approximation that describe self-gravitating scalar field configurations around a black hole, including angular momentum number $\ell$. An approach analogous to the one which gives rise to $\ell$-boson stars is used here to construct self-gravitating ``gravitational atoms" with $\ell\ge0$. We refer to these new solutions as {\it noble gravitational atoms}, by analogy with noble atoms, which are characterized by closed electron shells. We show that, in the proper limit, noble gravitational atoms approach $\ell$-boson stars globally, displaying noticeable differences only in a region very close to the event horizon. Noble gravitational atoms with $\ell>0$ sometimes present density maxima located at relatively large radii, with small density close to the horizon for $\ell>1$. Furthermore, they do not always present the typical density spike at the event horizon if $\ell > 0$; on the contrary, they sometimes exhibit a small dip there. When $\ell=0$, a spike can appear, but its contribution to the total mass density is always negligible. The size, density, and lifetime of these objects vary significantly depending on the parameters, being in some cases as large as galaxies, as dilute as dark matter, and as long-lived as the Universe itself. - oai:arXiv.org:2512.08095v1 + Gravitational-Wave Signatures of Massive Black Hole Formation + https://arxiv.org/abs/2512.09197 + arXiv:2512.09197v1 Announce Type: cross +Abstract: Direct-collapse black holes (DCBHs) are an important component of the massive black hole population of the early universe, and their formation and early mergers will be prominent in the data stream of the Laser Interferometer Space Antenna (LISA). However, the population and binary properties of these early black holes are poorly understood, with masses, mass ratios, spins, and orbital eccentricities strongly dependent on the details of their formation, and the properties of the remaining exterior material (baryonic and non-baryonic), which may be substantial to the point of merger. + We report on initial work to simulate the formation, collapse, and/or merger of such DCBH regions in order to extract the resulting gravitational-wave signals. + oai:arXiv.org:2512.09197v1 gr-qc astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 cross - http://creativecommons.org/licenses/by/4.0/ - Miguel Alcubierre, Juan Barranco, Argelia Bernal, Juan Carlos Degollado, Alberto Diez-Tejedor, Miguel Megevand, Dario Nunez, Olivier Sarbach + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Bernard J. Kelly, Sarah Gossan, Leonardo R. Werneck, John Wise, Zachariah B. Etienne, Thiago Assump\c{c}\~ao, Al\'aine Lee, John G. Baker - High-overtone ringdown fits: start time, no-hair tests, and correlations - https://arxiv.org/abs/2512.08098 - arXiv:2512.08098v1 Announce Type: cross -Abstract: Overtones are known to improve the performance of fits to the ringdown, both in numerical-relativity simulations and gravitational-wave observations. Although the overtone frequencies are a concrete prediction of general relativity, it remains an open question whether they are excited to the extent that fits would suggest. In this work, we take a pragmatic approach and investigate the practical utility of each additional overtone in extracting information from the ringdown. We look at the dependence of the ringdown start time on the number of overtones, and the feasibility of detecting deviations from general relativity in the ringdown frequencies. We suggest that there is no clear "maximum" overtone, but rather the utility of each additional overtone decreases compared to the one before. Finally, we perform Bayesian parameter estimation (as opposed to least-squares fits) to obtain posterior distributions on the overtone amplitudes and phases, allowing us to investigate their correlation structure. Due to strong correlations it becomes increasingly hard to measure individual amplitudes and phases for the highest overtones. However, we find that the joint measurement of overtone amplitudes (i.e., the correlation structure itself) is sensitive to the frequencies and decay times of even the highest overtones, possibly offering an avenue to perform consistency tests with general relativity. - oai:arXiv.org:2512.08098v1 - gr-qc + Investigating the interaction of a Cosmic String with an Accreting Black Hole + https://arxiv.org/abs/2512.09380 + arXiv:2512.09380v1 Announce Type: cross +Abstract: Rotating black holes when attached to a cosmic string have their rotational energy extracted leading to a change in its spin and mass. The spin of a black hole can be measured using various methods for an accreting black hole in an X-ray binary system. Accretion disks around black holes have an innermost stable circular orbit (ISCO) whose location is directly dependent on spin and mass of the black hole. The orbit's location changes as the black hole's spin changes and hence can be a method to detect the presence of cosmic strings. This study investigates this change and suggests the ejection of accretion material as black hole spin approaches maximum for prograde motion and material falling into the black hole for retrograde motion, regardless of the presence of cosmic string. However, in the presence of cosmic string, the spin-up process due to accretion is found out to be slower, even with high accretion rates and is detectable. There is a transition phase that occurs as the black hole approaches maximum spin, where even small changes in spin result in significant changes in the ISCO's position. Accreting black holes attached to a large string never reach this transition phase and this absence serves as potential evidence for the existence of a cosmic string. + oai:arXiv.org:2512.09380v1 + hep-th astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Erin Coleman, Eliot Finch + 10.1088/1402-4896/adce49 + Journal = Physica Scripta, year = 2025, month = June, volume = 100, number = 6, pages = 065008 + Ishan Swamy, Deobrat Singh - Probing Cosmic Strings via Black Hole Quasinormal Modes in Gravitational Wave Astronomy - https://arxiv.org/abs/2512.08368 - arXiv:2512.08368v1 Announce Type: cross -Abstract: Black holes, the simplest solution to Einstein's field equations, do not emit light, making their observations a major challenge for researchers. However, discovery of binary black holes (BBHs) in 2015 by LIGO has transformed the study of compact objects, with over 300 BBHs recorded, providing a new avenue for probing new physics. GWs remain a prominent and precise method of observing not only BBHs, but also dark matter and cosmic strings. Cosmic strings -- hypothetical one dimensional topological defects formed in the early universe, are yet to be observed, with multiple detection methods such as particle radiation, gravitational waves and lensing being proposed. Here we present a novel framework to search for cosmic strings by modeling them as perturbations within non-rotating black hole spacetime, focusing on their imprint on the spectrum of quasinormal modes (QNMs). Our numerical simulations identify a lower limit on perturbation strength, $\lambda \sim 10^{-10}$ for uncharged string and $\lambda \sim 10^{-7}$ for charged string, below which cosmic string effects become unobservable in QNM signals. By analyzing eigenvalue splitting and centers, we show that cosmic string properties impart distinct and detectable features to GW signals. Our results establish QNM analysis as a powerful, alternative observational strategy for constraining or detecting cosmic strings, and offer an inverse approach to estimate string energy or charge if a signal is detected. With upgrades in LIGO technologies and advanced multimessenger astronomy under development, these findings highlight new potential for detecting cosmic strings. - oai:arXiv.org:2512.08368v1 + Warm Inflation in a Braneworld Scenario + https://arxiv.org/abs/2512.09389 + arXiv:2512.09389v1 Announce Type: cross +Abstract: In the literature, many warm inflationary models are formulated. In this piece of work, a warm inflationary model in the braneworld scenario is studied, considering constant and variable dissipation coefficients. Performance of the model has been considered in both strong and weak dissipative regimes. We study the dynamics of this scenario under slow-roll approximation and estimate cosmological observables, viz., the spectral index and tensor-to-scalar ratio. In order to constrain the parameters in our model, we consider data from Planck 2018 and BICEP. + oai:arXiv.org:2512.09389v1 gr-qc astro-ph.CO - astro-ph.HE - hep-th - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Ishan Swamy, Deobrat Singh + Sabina Yeasmin, Atri Deshamukhya - Careless Whispers: A population of sub-threshold post-merger gravitational waves constrains the hot nuclear equation of state - https://arxiv.org/abs/2512.08497 - arXiv:2512.08497v1 Announce Type: cross -Abstract: We show how to coherently combine information from a population of sub-threshold, gravitational-wave binary neutron star post-merger remnants. Although no individual event in our synthetic population can be claimed as a confident detection, we show how to statistically determine the fraction of merger events that promptly collapse to form a black hole, compared to those for which a neutron star survives the merger for at least tens of milliseconds. This fraction, when combined with information about the neutron star mass distribution gleaned from the inspiral portion of the signals, provides an indirect measure of the neutron star maximum mass. Using conservative measures of the post-merger waveforms, we show that 50-70 events with binary neutron star inspiral measurements can be combined to give an $11-20\%$ fractional uncertainty on the maximum mass of rapidly rotating, hot neutron stars, which can potentially be turned into a $12-21\%$ fractional constraint on the Tolman-Oppenheimer-Volkoff mass. We discuss how this measure of the hot nuclear equation of state can be combined with information of cold neutron stars to see the effect of temperature on physics in the densest regions of the Universe. - oai:arXiv.org:2512.08497v1 + Improving the inference of the stellar quantities using the extended $I$-Love-$Q$-$\delta M$ relations + https://arxiv.org/abs/2512.09554 + arXiv:2512.09554v1 Announce Type: cross +Abstract: In relativistic Astrophysics the $I$-Love-$Q$ relations refer to approximately EoS-independent relations involving the moment of inertia, Love number, and quadrupole moment through some quantities that are normalised by the mass $M_0$ of the background configuration of the perturbative scheme. Since $M_0$ is not an observable quantity, this normalisation hinders the direct applicability of the relations. A common remedy assumes that $M_0$ coincides with the actual mass of the star $M_S$; however, this approximation is only adequate for very slow rotation (when the dimensionless spin parameter is $\chi_S<0.1$). The more accurate alternative approach, based on the $I$-Love-$Q$-$\delta M$ set of relations, circumvents this limitation by enabling the inference of $M_0$. Here we review both approaches and provide numerical comparisons. + oai:arXiv.org:2512.09554v1 gr-qc astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 cross - http://creativecommons.org/licenses/by/4.0/ - Fiona H. Panther, Paul D. Lasky + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Eneko Aranguren, Jos\'e A. Font, Nicolas Sanchis-Gual, Ra\"ul Vera - On the existence of bound states in SIMP dark sectors - https://arxiv.org/abs/2512.08517 - arXiv:2512.08517v1 Announce Type: cross -Abstract: In strongly interacting massive particle (SIMP) scenarios, dark matter is comprised of stable dark pions whose $3\to 2$ or $4\to 2$ reactions set the dark matter relic abundance. Recent work has shown that shallow two-pion bound states significantly affect the freeze-out, but did not establish whether such states actually form. In this work we demonstrate that a scalar isosinglet bound state does exist in a well-defined region of parameter space by solving an on-shell Lippmann--Schwinger equation in a chiral-unitary framework and analyzing the $S$-wave $\pi\pi$ amplitude in the complex energy plane. We determine the range of $m_\pi/f_\pi$ for which a pole appears below the two-pion threshold, extract the corresponding residue, and, in the non-relativistic limit, obtain the bound-state wave function at the origin, $|\Psi(0)|$, which controls bound-state-assisted annihilation and decay rates relevant for catalyzed freeze-out. Comparing this T-matrix based result with variational estimates using simple finite-range potentials, we find agreement within order-one factors for shallow binding. For binding energies of order the freeze-out temperature, $E_B \sim m_\pi/20$, we obtain $|\Psi(0)|\sim \mathcal{O}(0.1)\,m_\pi^{3/2}$, thereby supporting the parametric assumptions used in previous phenomenological analyses. - oai:arXiv.org:2512.08517v1 - hep-ph - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Rogue Vertical Drafts in the Mesosphere and Lower Thermosphere: Evidence and Implications + https://arxiv.org/abs/2512.09612 + arXiv:2512.09612v1 Announce Type: cross +Abstract: Observational evidence of extreme vertical velocities (|w| ge 12.5 m/s and at times greater than 50 m/s) in the mesosphere and lower thermosphere (MLT), has emerged in recent years. We refer to these events as Rogue Vertical Drafts (RVDs). They exceed five standard deviations of observed vertical velocities and appear as paired updraft-downdraft structures in varicose mode. Four-dimensional observations reveal that RVDs are intermittent, recurrent, and unpredictable. On average, they are expected to occur every sim 12 days during summer over Northern Norway, assuming a 1000 s interval. Different instruments may capture only portions of these events, for example, only upward or downward drafts when restricted to a single altitude range. Despite their rarity, their magnitudes and frequency suggest potential impacts on dust-sized matter escaping from planets, natural and anthropogenic space material, and MLT climate and processes. We propose that RVDs are a fundamental yet under-recognized feature of the MLT, underscoring the need for global observations to assess their prevalence and significance. + oai:arXiv.org:2512.09612v1 + physics.ao-ph + astro-ph.EP + Thu, 11 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Xiaoyong Chu, Josef Pradler, Daris Samart + 10.3389/fspas.2025.1716224 + Frontiers in Astronomy and Space Sciences 2025 + J. L. Chau, A. Berera, D. Huyghebaert - Time-Averaged Template for Stochastic Gravitational-Wave Background Detection in Space-Based Interferometers - https://arxiv.org/abs/2512.08521 - arXiv:2512.08521v1 Announce Type: cross -Abstract: Stochastic gravitational-wave background (SGWB) poses significant challenges for data analysis and parameter inference in future space-based gravitational-wave missions, such as LISA and Taiji, as it appears as an additional stochastic component along with instrumental noise. Previous studies have developed various approaches to distinguish the SGWB from instrumental noise, often under simplified assumptions such as static or equal-arm configurations. However, in realistic scenarios, time-varying arm-lengths introduce additional complexities that require careful modeling. In this work, we investigate the impact of template construction on SGWB parameter estimation under realistic orbital configurations. Using the simulated SGWB signals and dominant instrumental noise sources, we compare three template strategies: time-averaged template constructed from segmented data, equal-arm template, and a template treating the arm-lengths as a free parameter. Our results show that the time-averaged template yield improves parameter estimation accuracy under time-varying arm-lengths, whereas introducing the effective arm-length as a free parameter increases estimation uncertainty. These findings highlight the importance of realistic template construction for high-precision SGWB analysis in future space-based missions. - oai:arXiv.org:2512.08521v1 - gr-qc + Bayesian Model Selection with an Application to Cosmology + https://arxiv.org/abs/2512.09724 + arXiv:2512.09724v1 Announce Type: cross +Abstract: We investigate cosmological parameter inference and model selection from a Bayesian perspective. Type Ia supernova data from the Dark Energy Survey (DES-SN5YR) are used to test the \(\Lambda\)CDM, \(w\)CDM, and CPL cosmological models. Posterior inference is performed via Hamiltonian Monte Carlo using the No-U-Turn Sampler (NUTS) implemented in NumPyro and analyzed with ArviZ in Python. Bayesian model comparison is conducted through Bayes factors computed using the \texttt{bridgesampling} library in R. The results indicate that all three models demonstrate similar predictive performance, but \(w\)CDM shows stronger evidence relative to \(\Lambda\)CDM and CPL. We conclude that, under the assumptions and data used in this study, \(w\)CDM provides a better description of cosmological expansion. + oai:arXiv.org:2512.09724v1 + stat.AP astro-ph.CO - astro-ph.IM - Wed, 10 Dec 2025 00:00:00 -0500 + stat.ME + Thu, 11 Dec 2025 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ - Jing-yi Wu, Yong Tang + Nikoloz Gigiberia - Superluminal constraints from ultra-high-energy neutrino events - https://arxiv.org/abs/2512.08523 - arXiv:2512.08523v1 Announce Type: cross -Abstract: The $\sim 100\,$PeV neutrino detected by KM3NeT marks the beginning of ultra-high-energy neutrino astronomy and provides a powerful probe of Lorentz Invariance Violation (LIV). In superluminal scenarios, neutrinos can decay through vacuum $e^-e^+$ pair emission or neutrino splitting. Previous analyses of the KM3-230213A event relied on simplified survival-probability estimates and, in some cases, used inaccurate decay-width expressions or neglected redshift and threshold effects. In this work we present a unified and self-consistent framework that corrects these issues and applies to both the energy-independent ($n=0$) and quadratic ($n=2$) superluminal cases. We collect and recast the decay-width and threshold expressions, clarify their flavor dependence, and include a consistent treatment of cosmological propagation. We also assess the impact of cascade regeneration and show that cascade effects are negligible for the purpose of setting LIV bounds. The survival-probability approximation adopted in previous works is therefore justified, while our framework provides a coherent basis for future analyses of superluminal neutrino constraints, which should consistently include possible time-delay signatures. - oai:arXiv.org:2512.08523v1 - hep-ph - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Oceanic internal tides: do they get phased at the Equator? + https://arxiv.org/abs/2512.09728 + arXiv:2512.09728v1 Announce Type: cross +Abstract: Low-mode baroclinic tides play a major role in ocean dynamics, especially for energy redistribution and deep ocean mixing. These internal waves, generated by tidal flow over submarine topography, can propagate for thousands of kilometres across ocean basins, and become unstable through wave-mean flow or wave-wave interactions. Satellite observations of internal tides have shown that part of their lunar semidiurnal (M2) altimetry signal loses phase coherence in equatorial regions, thus affecting how we interpret their dynamics and energy distribution (Buijsman et al. 2017). We investigate the interaction of a baroclinic M2 internal tide wavepacket with an equatorial zonal jet, possibly of any horizontal or vertical structure. The dynamics of the low modes are explored as well as the potential excitation of higher vertical modes and how these interactions can generate incoherences in the baroclinic tide signal. + We develop an idealized linear model using modal decomposition (Kelly et al. 2016), which is solved using Dedalus, to study the dynamics of a mode 1 M2 internal wavepacket on an equatorial beta plane. A zonal jet, with a uniform or a sheared vertical structure, is added at the equator to investigate potential wave-mean flow interaction. We find that a vertically uniform zonal jet affects the propagation of the mode 1 wavepacket. Depending on the strength of the jet, this can cause total reflection or strong distortion of the wavepacket. In contrast, a wavepacket entering a vertically sheared jet shows energy scattering into higher modes, which have lower phase and group speeds, shorter wavelengths, and are thus more susceptible to dissipation (and critical layers for non-uniform stratification). As the wavepacket exits the jet, reverse energy transfer occurs and the phase speed difference between the modes may explain part of the phase incoherence observed in altimetry data. + oai:arXiv.org:2512.09728v1 + physics.ao-ph + astro-ph.EP + physics.flu-dyn + Thu, 11 Dec 2025 00:00:00 -0500 cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - J. M. Carmona, J. L. Cort\'es, M. A. Reyes + http://creativecommons.org/licenses/by/4.0/ + Camille Moisset, Bruce Sutherland, Lois Baker - Dark Photons in the Early Universe: From Thermal Production to Cosmological Constraints - https://arxiv.org/abs/2512.08528 - arXiv:2512.08528v1 Announce Type: cross -Abstract: Dark photons, a generic class of light gauge bosons that interact with the Standard Model (SM) exclusively through kinetic mixing, arise naturally in many gauge extensions of the SM. Motivated by these theoretical considerations, we present a comprehensive analysis of their thermal production in the early universe. Our calculation covers a broad range of dark photon masses from 0.1 keV to 100 MeV and include inverse decay, annihilation, and semi-Compton processes. Wherever possible, we present analytical estimates of the production rates and yields, and verify their accuracy numerically. For dark photons lighter than twice the electron masses (around 1 MeV), we find that our analytical estimate of the freeze-in yield based on resonant production is very accurate, implying that off-resonance contributions can be neglected in practice. For heavy dark photons, although this conclusion no longer holds, we derive an interesting ratio, $4\pi e/27\approx0.14$, with $e$ the coupling constant of QED, that can be used to estimate the relative importance of on- and off-resonance contributions. Finally, using the calculated abundance of dark photons in the early universe, we derive cosmological constraints on the dark photon mass and kinetic mixing. Compared with bounds from stellar cooling and supernovae, the cosmological constraints are most stringent in the mass range from 0.1 MeV to 6 MeV, within which kinetic mixing at the level of $10^{-12}\sim10^{-10}$ can be probed. - oai:arXiv.org:2512.08528v1 + Reconciling ALP Dark Matter and Electroweak Baryogenesis through First-Order Electroweak Phase Transition + https://arxiv.org/abs/2512.09760 + arXiv:2512.09760v1 Announce Type: cross +Abstract: We show that an axionlike particle (ALP) can simultaneously generate the baryon asymmetry and constitute dark matter through dynamics triggered by a first-order electroweak phase transition (EWPT). In our proposal, the transition briefly reshapes the ALP potential via a temperature-dependent vacuum expectation value of a scalar field $S$, responsible for making the EWPT of first order, inducing a transient mass enhancement of ALP via higher-dimensional $U(1)$-breaking operator(s). This sudden kick generates a large ALP velocity near the onset of EWPT enabling the broadening of relic satisfied parameter space and predict a complementary stochastic gravitational-wave signal from the underlying first-order transition. We further show that the same ALP dynamics can naturally fuel electroweak baryogenesis through its coupling to electroweak anomaly. + oai:arXiv.org:2512.09760v1 hep-ph astro-ph.CO - hep-ex - Wed, 10 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Xun-Jie Xu, Boting Zhou - - - Centrifugal instability of Taylor-Couette flow in stratified and diffusive fluids - https://arxiv.org/abs/2512.08664 - arXiv:2512.08664v1 Announce Type: cross -Abstract: The linear and non-linear dynamics of centrifugal instability in Taylor-Couette flow are investigated when fluids are stably stratified and highly diffusive. One-dimensional local linear stability analysis (LSA) on cylindrical Couette flow confirms that the stabilising role of stratification on centrifugal instability is suppressed by strong thermal diffusion (i.e. low Prandtl number $Pr$). For $Pr\ll1$, it is verified that the instability dependence on thermal diffusion and stratification with the non-dimensional Brunt-V\"ais\"al\"a frequency $N$ can be prescribed by a single rescaled parameter $P_{N}=N^{2}Pr$. From direct numerical simulation (DNS), various non-linear features such as axisymmetric Taylor vortices at saturation, secondary instability leading to non-axisymmetric patterns or transition to chaotic states are investigated for various values of $Pr\leq1$ and the Reynolds number $Re_{i}$. Two-dimensional bi-global LSA on axisymmetric Taylor vortices, which appear as primary centrifugal instability saturates nonlinearly, is also performed to find the secondary critical Reynolds number $Re_{i,2}$ at which the Taylor vortices become unstable by non-axisymmetric perturbation. The bi-global LSA reveals that $Re_{i,2}$ increases (i.e. the onset of secondary instability is delayed) in the range $10^{-3}<Pr<1$ at $N=1$ or as $N$ increases at $Pr=0.01$. Secondary instability leading to highly non-axisymmetric or irregular chaotic patterns is further investigated by the 3D DNS. The Nusselt number $Nu$ is also computed from the torque at the inner cylinder for various $Pr$ and $Re_{i}$ at $N=1$ to describe how the angular momentum transfer increases with $Re_{i}$ and how $Nu$ varies differently for saturated and chaotic states. - oai:arXiv.org:2512.08664v1 - physics.flu-dyn - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + hep-th + Thu, 11 Dec 2025 00:00:00 -0500 cross - http://creativecommons.org/licenses/by/4.0/ - 10.1017/jfm.2025.261 - Junho Park + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Dipendu Bhandari, Soumen Kumar Manna, Arunansu Sil - Single-field D-type inflation in the minimal supergravity in light of Planck-ACT-SPT data - https://arxiv.org/abs/2512.08760 - arXiv:2512.08760v1 Announce Type: cross -Abstract: The minimal supergravity framework is applied to a construction of new D-type single-field models of inflation in agreement with precision measurements of the cosmic microwave background radiation by Planck Collaboration, BICEP/Keck Collaboration, Atacama Cosmology Telescope and South Pole Telescope. The inflaton potential, the power spectrum of scalar perturbations, the cosmological observables and the reconstruction procedure can be very simple when using the e-folds as the running variable. - oai:arXiv.org:2512.08760v1 + Relativistic accretion process onto rotating black holes in Einstein-Euler-Heisenberg nonlinear electrodynamic gravity + https://arxiv.org/abs/2512.09845 + arXiv:2512.09845v1 Announce Type: cross +Abstract: In this study, we uncover the accretion dynamics and oscillatory behavior around rotating black holes within the EEH nonlinear electrodynamic framework by analyzing both the motion of test particles and numerically solving the general relativistic hydrodynamic equations. Using EEH geometry, we compute the structure of circular motion, the effective potential and force, and we evaluate the orbital, radial, and vertical epicyclic frequencies together with the Lense-Thirring and periastron precession rates. Our calculations show that, compared to the Kerr model, the charge parameter $Q$ and the spin parameter $a$ significantly modify the strong gravitational field and shift the characteristic frequencies. We then model the dynamical structure formed by matter accreting toward the EEH black hole through the BHL mechanism, finding that the parameter $Q$ increases the amount of infalling matter and strengthens shock-cone instabilities near the horizon, while farther from the black hole it suppresses accretion and reduces turbulence. Time-series analysis of the accretion rate reveals robust QPOs, whose low-frequency components arise from the precession of the shock cone, while high-frequency components appear as a consequence of strong-field instabilities modified by $Q$ and $a$. A systematic parameter-space exploration identifies the regions where EEH corrections maximize QPO activity, indicating that nonlinear electrodynamics can leave observable imprints on accretion flows and may be testable with QPO and horizon-scale observations. + oai:arXiv.org:2512.09845v1 gr-qc astro-ph.CO hep-th - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yermek Aldabergenov, Sergei V. Ketov + Orhan Donmez, G. Mustafa, Himanshu Chaudhary, M. Yousaf, Abdelmalek Bouzenada, Allah Ditta, Farruh Atamurotov - The Strong-$CP$ Problem and its Gauge Axion solution as Evidence for Fundamental Strings - https://arxiv.org/abs/2512.08834 - arXiv:2512.08834v1 Announce Type: cross -Abstract: The topological susceptibility of the QCD vacuum provides an understanding of $\theta$-vacua as vacua of a Chern-Simons gauge theory. In this way, it gives an immediate proof of the physicality of the boundary $\theta$-term. This makes the essence of the strong-$CP$ puzzle very transparent and offers a solution in form of the gauge axion, which has exact quality. This axion represents an intrinsic part of the QCD gauge redundancy without any reference to an anomalous global symmetry. It is a two-form transforming under the QCD gauge symmetry. Due to its pure gauge nature, the gauge axion represents a powerful tool to monitor physics of $\theta$-vacua in various regimes. Unlike the ordinary Peccei-Quinn axion, which is UV-completed into a Goldstone phase of a complex scalar and thereby suffers from the quality problem, the gauge axion is UV-completed directly into a fundamental theory of gravity. We study the domain wall and string structure of the gauge axion and show that the strings sourcing it must be a part of this fundamental theory. We thus observe that the absence of the axion quality problem motivates the presence of fundamental strings. This provides a new argument for a connection between the axion and gravity. - oai:arXiv.org:2512.08834v1 - hep-th + On priors and scale cuts in EFT-based full-shape analyses + https://arxiv.org/abs/2410.16358 + arXiv:2410.16358v2 Announce Type: replace +Abstract: Parameter estimation from galaxy survey data from the full-shape method depends on scale cuts and priors on EFT parameters. The effects of priors, including the so-called ''prior volume'' phenomenon have been originally studied in Ivanov et al. (2019) and subsequent works. In this note, we repeat and extend these tests and also apply them to other priors used in the literature. We point out that in addition to the ''prior volume'' effect there is a more dangerous effect that is largely overlooked: a systematic bias on cosmological parameters due to overoptimistic scale cuts. Unlike the ''prior volume'' effect, this is a genuine systematic bias due to two-loop corrections that does not vanish with better priors or with larger data volumes. Our study is based on the high fidelity BOSS-like PT Challenge simulation data which offer many advantages over analyses based on synthetic data generated with fitting pipelines. We show that some analysis choices associated with the PyBird code, especially the scale cuts, significantly bias parameter recovery, overestimating $\sigma_8$ by over $5\%$ (equivalent to $1\sigma$). The bias on measured EFT parameters is even more significant. In contrast, the analysis choices associated with the CLASS-PT code lead to much smaller ($\lesssim 1\%$) shifts in cosmological parameters based on their best-fit values. + oai:arXiv.org:2410.16358v2 astro-ph.CO hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Gia Dvali, Lucy Komisel, Otari Sakhelashvili, Anja Wachowitz + Thu, 11 Dec 2025 00:00:00 -0500 + replace + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Anton Chudaykin, Mikhail M. Ivanov, Takahiro Nishimichi - A Bayesian Approach Study of Hybrid Neutron Stars - https://arxiv.org/abs/2512.08911 - arXiv:2512.08911v1 Announce Type: cross -Abstract: In this work, we explore how astronomical observations (specifically measurements of masses, radii, and tidal deformabilities) can constrain the presence of quark matter inside neutron stars, namely the phase transition from nuclear matter to deconfined quark matter. Our approach employs Bayesian analysis to study this phenomenon. Hadronic matter is modeled using the relativistic mean-field (RMF) approximation, for which we have selected two parameter sets: \(NL3^{*}\omega\rho\), representing hadronic matter with nucleons only, and $EL3\omega\rho$ with nucleons only and $EL3\omega\rho Y$, which includes hyperons. On the other hand deconfined quark matter is modeled using the vector-MIT bag model. For our purpose, the phase transition is implemented using the Maxwell construction. Bayesian inference is performed by tuning three parameters: the bag constant (i.e. $B^{1/4}$), the vector coupling constant \(\left(G_{v}\right)\), and the Dirac sea contribution ($b_{4}$). We found that a phase transition could exist at densities below \(2.0\,n_{0}\) for both the $EL3\omega\rho - EL3\omega\rho Y $ and $NL3^{*}\omega\rho$ parametrizations. As a consequence, our results also indicate that a hybrid neutron star could have a large quark core that comprises more than \(80\%\) of its size. - oai:arXiv.org:2512.08911v1 - nucl-th - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 - cross + The Role of Planetary-Scale Waves on the Stratospheric Superrotation in Titan's Atmosphere + https://arxiv.org/abs/2503.15728 + arXiv:2503.15728v2 Announce Type: replace +Abstract: We analyze simulation results from the TitanWRF global circulation model to understand the mechanisms that maintain the equatorial superrotation in Titan's stratosphere. We find that the eddies associated with wave activities can transport angular momentum upgradient to zonal flow, leading to acceleration of the equatorial superrotation. The dominant wave modes identified in this study are consistent with previous studies, with zonal wavenumber 1 being the major contributor to the prograde acceleration. Despite the same conclusion of maintenance of equatorial superrotation via wave-mean interactions, we find that the way waves interact with the zonal flow in TitanWRF is slightly different from some other studies. We confirm our previous findings that in TitanWRF this occurs primarily during a dozen or so annual, short-duration (a few Titan sols) angular momentum "transfer events", which have a repeatable seasonal pattern but differ slightly in timing and magnitude between years. This is not the case in the Titan Atmosphere Model (TAM), which found milder angular momentum transfers that produced the strongest acceleration of superrotation around solstice in the upper stratosphere and more continuous year-around acceleration in the lower stratosphere. Despite differences in angular momentum transfer across models, we further find that, similar to the TAM wave analysis results, eddies generated by Rossby-Kelvin instabilities may be the major source of prograde angular momentum for the equatorial superrotation, although TitanWRF may also include contributions from the absorption of vertically propagating equatorial Kelvin waves. This differs from our previous work, which suggested barotropic waves were responsible for TitanWRF's solsticial transfer event. + oai:arXiv.org:2503.15728v2 + astro-ph.EP + physics.ao-ph + Thu, 11 Dec 2025 00:00:00 -0500 + replace http://creativecommons.org/licenses/by/4.0/ - F\'abio K\"opp, C\'esar H. Lenzi, C\'esar V. Flores, and D\'ebora P. Menezes + Yuan Lian, Cecilia Leung, Claire Newman, Leslie Tamppari - Near-infrared Variability Detected in the Young Star-Forming Dwarf Galaxy SBS 0335-052E - https://arxiv.org/abs/2304.03726 - arXiv:2304.03726v3 Announce Type: replace -Abstract: SBS~0335-052E is a young star-forming dwarf galaxy with a total stellar mass of $M_{*} \lesssim 10^{8}~M_{\odot}$ and an extremely low metallicity ($Z \sim 1/40~Z_{\odot}$), which has long been considered to be devoid of an active galactic nucleus (AGN). Here we report the detection of temporal flux variability of SBS~0335-052E in near-infrared (NIR) 3-4\ ${\rm \mu}$m bands on timescales of several years, showing dimming and brightening of up to 50\% over 14~years, based on archival data from the Wide-field Infrared Survey Explorer. Our spectral energy distribution (SED) fitting of archival ultraviolet (UV)-NIR photometry, including AGN SED models, indicates that the variable NIR emission arises from an edge-on AGN dust torus. The UV-optical emission from the accretion disk is obscured and does not reach us, leading to the dominance of the host galaxy's young stellar population in the UV-optical wavelengths. This analysis favors the presence of a Compton-thick, heavily obscured AGN in SBS~0335-052E, consistent with its observed X-ray weakness. From the SED fitting, we estimate an AGN bolometric luminosity of $L_{\rm bol} = 1.2\times10^{43}\ {\rm erg\ s^{-1}}$, which implies a black hole mass of $M_{\rm BH} \simeq 10^{5}\ M_\odot$ if the AGN is accreting at the Eddington limit. If confirmed, SBS~0335-052E would be the least massive galaxy known to host an AGN, likely harboring an intermediate-mass black hole. - oai:arXiv.org:2304.03726v3 + A Short History of (Orbital) Decay: Roman's Prospects for Detecting Dying Planets + https://arxiv.org/abs/2504.15277 + arXiv:2504.15277v2 Announce Type: replace +Abstract: The Roman Space Telescope Galactic Bulge Time Domain Survey (GBTDS) is expected to detect ~$10^5$ transiting planets. Many of these planets will have short orbital periods and are thus susceptible to tidal decay. We use a catalog of simulated transiting planet detections to predict the yield of orbital decay detections in the Roman GBTDS. Assuming a constant stellar tidal dissipation factor, $Q^{'}_{*}$, of $10^6$, we predict ~ 5 - 10 detections. We additionally consider an empirical period-dependent parameterization of $Q^{'}_{*} \propto P^{-3}$ and find a substantially suppressed yield. We conclude that Roman will provide constraints on the rate of planet engulfment in the Galaxy and probe the physics of tidal dissipation in stars. + oai:arXiv.org:2504.15277v2 + astro-ph.EP astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Shun Hatano, Mitsuru Kokubo, Masami Ouchi, Kimihiko Nakajima, Toshihiro Kawaguchi, Satoshi Kikuta, Nozomu Tominaga, Yi Xu, Kuria Watanabe, Yuichi Harikane, Yuki Isobe, Akinori Matsumoto, Moka Nishigaki, Yoshiaki Ono, Masato Onodera, Yuma Sugahara, Hiroya Umeda, Yechi Zhang, Ryotaro Chiba, Takashi J. Moriya + http://creativecommons.org/licenses/by/4.0/ + Kylee Carden, B. Scott Gaudi, Robert F. Wilson - Particle acceleration and multi-messenger radiation from Ultra-Luminous X-ray Sources: A new class of Galactic PeVatrons - https://arxiv.org/abs/2411.08762 - arXiv:2411.08762v2 Announce Type: replace -Abstract: Super-Eddington accretion onto stellar-mass compact objects powers fast outflows in ultra-luminous X-ray sources (ULXs). Such outflows, which can reach mildly relativistic velocities, are often observed forming bubble structures. Wind bubbles are expected to develop strong wind termination shocks, which are sites of great interest for diffusive shock acceleration. We developed a model of diffusive shock acceleration in the wind bubbles powered by ULXs. We find that the maximum energy in these objects can easily reach the PeV range, promoting winds from ULXs as a new class of PeVatrons. We specialized our model in the context of the Galactic source SS433 and show that high-energy protons in the bubble might explain the highest energy photons (>100 TeV) and their morphology recently observed by LHAASO. In this paper, we discuss the detectability of such a source in neutrinos, and we analyze the possible radio counterpart of ULXs focusing on the case of W50, the nebula surrounding SS433. Finally, we discuss the possible contribution of Galactic ULXs to the cosmic-ray flux at the knee, concluding that their role could be significant only if one of these sources, currently undetected, were sufficiently close. - oai:arXiv.org:2411.08762v2 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + SHELLQs. Bridging the Gap: JWST Unveils Obscured Quasars in the Most Luminous Galaxies at z > 6 + https://arxiv.org/abs/2505.04825 + arXiv:2505.04825v3 Announce Type: replace +Abstract: The unprecedented sensitivity of the James Webb Space Telescope (JWST) has uncovered a surprisingly abundant population of mildly obscured, low-luminosity active galactic nuclei (AGNs) in the epoch of reionization (EoR). However, the link between these objects and classical unobscured quasars remains a mystery. Here we report the discovery of obscured quasars hosted by the most luminous galaxies at z > 6, possibly bridging the gap between the two AGN populations. The 13 objects presented here were originally selected from a rest-frame ultraviolet (UV) imaging survey over >1000 deg2, and were known to have luminous (>10^{43} erg/s) narrow Ly-alpha emission. With JWST/NIRSpec follow-up observations, we found that 7 out of 11 objects with narrow Ly-alpha exhibit a broad component in H I Balmer lines and He I lines, but not in [O III] and other forbidden lines. Mild dust obscuration (0 < Av < 3) is inferred from the Balmer decrements. The estimated intrinsic luminosities suggest that our broad line (BL) objects are the long-sought UV-obscured counterparts of luminous quasars in the EoR. They host supermassive black holes (SMBHs) with masses 10^(7.8-9.1) Msun, undergoing sub-Eddington to Eddington accretion. Most of the BL objects are spatially unresolved, and are close to "little red dots" with their blue rest-UV and red rest-optical colors. We estimate the AGN number density among similarly luminous Ly-alpha emitters to be larger than 2 x 10^(-8) /Mpc3. This density is comparable to that of classical quasars with similar continuum luminosities, suggesting that a substantial fraction of active SMBHs are obscured in the EoR and have been overlooked in past rest-UV surveys. + oai:arXiv.org:2505.04825v3 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1051/0004-6361/202452987 - A&A 698, A188 (2025) - Enrico Peretti, Maria Petropoulou, Georgios Vasilopoulos, Stefano Gabici + http://creativecommons.org/licenses/by/4.0/ + 10.3847/1538-4357/addf4e + ApJ 988, 57 (2025) + Yoshiki Matsuoka, Masafusa Onoue, Kazushi Iwasawa, Kentaro Aoki, Michael A. Strauss, John D. Silverman, Xuheng Ding, Camryn L. Phillips, Masayuki Akiyama, Junya Arita, Masatoshi Imanishi, Takuma Izumi, Nobunari Kashikawa, Toshihiro Kawaguchi, Satoshi Kikuta, Kotaro Kohno, Chien-Hsiu Lee, Tohru Nagao, Ayumi Takahashi, Yoshiki Toba - Andromeda's tenuous veil: A likely Milky Way nebula projected toward M31 - https://arxiv.org/abs/2412.08327 - arXiv:2412.08327v2 Announce Type: replace -Abstract: A large, faint nebula was unexpectedly discovered near M31 using narrowband [O III] images. Its apparent size and the lack of a clear counterpart at other wavelengths make it unique and challenging to explain. We aim to determine whether the nebula is extragalactic or located within the Milky Way. This will enable us to constrain its physical properties and assess its nature. To do so, we obtained deep narrowband [O II]3727 and H$\alpha$+[NII] observations with the JAST80 telescope at the Observatorio Astrof\'isico de Javalambre, as well as high spectral resolution spectroscopy (R~5000) at four locations within the region of interest using MEGARA at the Gran Telescopio Canarias. We found extended [O II] emission along two near-parallel strands to the [O III], offset by six arcmin. The nebular spectra reveals up to 6 emission lines from [O III]4959,5007, H$\beta$, [N II]6583, and [S II]6716,6731. Their receding velocities are above $-$40 km s$^{-1}$, far from the systemic velocity of M31 ($-$300 km s$^{-1}$). The fluxes and velocities are consistent for the same lines across different regions of the nebula. The nebular properties suggest a location within the Milky Way rather than being physically associated with M31. The most likely scenario is a resolved ionization structure in a Galactic nebula with a separation between [O II] and [O III] of a few parsecs. The observed receding velocities would be unprecedented for an object physically linked to M31 but are common for nearby gas filaments. Their consistency across the nebula would also be unusual if it were larger than a kiloparsec. The analysis of the emission-line ratios, line widths, and morphology suggests the possibility of it being an interstellar gas filament with an additional source of ionization to explain the [O III] emission. However, the complex properties of this object call for further observations to confirm its nature. - oai:arXiv.org:2412.08327v2 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Average Power-Density Spectrum of short and long Fermi-GBM Gamma-Ray Bursts + https://arxiv.org/abs/2506.09610 + arXiv:2506.09610v2 Announce Type: replace +Abstract: Gamma-ray bursts (GRBs) are the most powerful electromagnetic outbursts in the Universe and emit a vast amount of their energy in the form of gamma rays. Their duration is extremely short on cosmic timescales, but they show a wealth of time variability in their light curves. Properties of this variability may carry information about the processes the gamma rays emerge from, which are still poorly understood. This research investigates the redshift-corrected gamma-ray light curves of 159 long GRBs, observed with the Gamma-Ray Burst Monitor on the Fermi Gamma-Ray Space Telescope between 2008 and 2023. We calculate the average power-density spectrum (PDS) of different groups of GRBs that are distinguished based on fluence, peak rate, duration, redshift, and the different GRB phases. Almost all redshift-corrected spectra reveal a power-law behavior with high-frequency power-law indices distributed around $\sim -1.9 \pm 0.2$. The precursor phase and redshift-corrected short bursts exhibit a shallower power law with index $\sim -1.30 \pm 0.04$, potentially due to the limited statistics that these samples represent. Only in some cases, the high-frequency index is still consistent with the $-5/3$ (Kolmogorov) slope, found by earlier studies and linked to the appearance of fully developed turbulence. + oai:arXiv.org:2506.09610v2 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1051/0004-6361/202453413 - Astronomy & Astrophysics, Volume 740, id.A224, December 2025 - A. Lumbreras-Calle, J. A. Fern\'andez-Ontiveros, R. Infante-Sainz, M. Akhlaghi, B. Montoro-Molina, B. P\'erez-D\'iaz, A. del Pino, H. Vives-Arias, A. Hern\'an-Caballero, C. L\'opez-Sanjuan, M. A. Mart\'in-Guerrero, S. Eskandarlou, A. Ederoclite + 10.1103/9gtg-bwfy + Phys. Rev. D 112, 2025, 083038 + Else Magnus, Jannes Loonen, Rose S. Stanley, Paul Coppin, Krijn D. de Vries, Nick van Eijndhoven - Exploring sub-GeV Dark Matter Physics with Cosmic Ray and Future Telescopes - https://arxiv.org/abs/2503.22148 - arXiv:2503.22148v2 Announce Type: replace -Abstract: If sub-GeV Dark matter(DM) annihilates to the charged particles such as $e^+ e^-$, $\mu^+ \mu^-$, or $\pi^+ \pi^-$, it generates an additional source of electrons and positrons in the cosmic ray (CR) population within our Milky Way. During propagation, these secondary electrons and positrons undergo reacceleration processes, boosting their energies to the GeV scale. Observatories like AMS-02 can detect these high-energy particles, enabling constraints on the properties of sub-GeV DM. By analyzing AMS-02 electron and positron data, the 95\% upper limits on the DM annihilation cross-section have been established in the range of $10^{-28}$ to $10^{-27}$ cm$^3\,$s$^{-1}$, corresponding to DM masses ranging from 100 MeV to 1 GeV. Meanwhile, MeV telescopes will provide complementary constraints on DM properties by detecting photon emissions from such annihilation processes. Notably, the sensitivity of future MeV gamma-ray observatories is projected to approach or match the constraints derived from CR data. - oai:arXiv.org:2503.22148v2 + Studies of stationary features in jets: 3C 279 quasar I. On-sky scattering and dynamics + https://arxiv.org/abs/2506.12457 + arXiv:2506.12457v2 Announce Type: replace +Abstract: A recent study on the dynamics of the quasi-stationary component (QSC) in the jet of BL~ Lacertae highlighted its significance in evaluating the physical properties of relativistic transverse waves in the parsec-scale jet. Motivated by this finding, we selected a different type of blazar, the flat-spectrum radio quasar (FSRQ) 3C~279, which hosts a QSC at an angular median distance of 0.35~mas from the radio core, as revealed by 27 years of VLBA monitoring data at 15~GHz. We investigate the positional scatter and dynamics of a QSC in the 3C~279 jet, aiming to detect the presence of a relativistic transverse wave and estimate its characteristics. We employ an analytical statistical method to estimate the mean intrinsic speed of the QSC, while moving average and refinement methods are used to smooth its trajectory. Analysis of the QSC position scatter shows that the jet axis change its direction by about $21^{\circ}$ over 27 years and jet mean intrinsic full opening angle is $\approx 0.30^{\circ} \pm 0.03^{\circ}$. The apparent displacement vectors of the QSC exhibit strong asymmetry and anisotropy along the jet direction, indicating pronounced anisotropic displacements of the core along the jet axis. We estimated the mean intrinsic speed of the QSC to be superluminal, $\overline{\beta_{\rm s}} \approx 10$ in units of the speed of light, which, within the framework of the seagull-on-wave model, is interpreted as evidence for a relativistic transverse wave propagating through the QSC. Analysis of the reversing trajectory of the QSC enables the classification and characterisation of reversal patterns, which, in turn, allows the determination of key transverse wave parameters such as frequency, amplitude, inclination angle, and magnetic energy of the wave (abbrev.). + oai:arXiv.org:2506.12457v2 + astro-ph.GA astro-ph.HE - hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - 10.1140/epjc/s10052-025-14998-x - Eur. Phys. J. C (2025) 85:1348 - Guansen Wang, Bing-Yu Su, Lei Zu, Lei Feng + 10.1051/0004-6361/202555927 + T. G. Arshakian, L. A. Hambardzumyan, A. B. Pushkarev, D. C. Homan, E. L. Karapetyan - Euclid: Quick Data Release (Q1) - A photometric search for ultracool dwarfs in the Euclid Deep Fields - https://arxiv.org/abs/2503.22497 - arXiv:2503.22497v2 Announce Type: replace -Abstract: We present a catalogue of 5306 new ultracool dwarf (UCD) candidates in the three Euclid Deep Fields in the Q1 data release. They range from late M to late T dwarfs, and include 1200 L and T dwarfs. A total of 546 objects have been spectroscopically confirmed, including 329 L dwarfs and 26 T dwarfs. We also provide empirical Euclid colours as a function of spectral type. Our UCD selection criteria are based only on colour ($I_\mathrm{E}-Y_\mathrm{E}>2.5$). The combined requirement for optical detection and stringent signal-to-noise ratio threshold ensure a high purity of the sample, but at the expense of completeness, especially for T dwarfs. The detections range from magnitudes 19 and 24 in the near-infrared bands, and extend down to 26 in the optical band. We discuss Euclid's capability to identify UCD candidates based on its photometric passbands. The average surface density of detected UCDs on the sky is approximately 100 objects per $\mathrm{deg}^2$, including 20 L and T dwarfs per $\mathrm{deg}^2$. This leads to an expectation of at least 1.4 million ultracool dwarfs in the final data release of the Euclid Wide Survey, including at least $300\,000$ L dwarfs, and more than 2600 T dwarfs, using the strict selection criteria from this work. - oai:arXiv.org:2503.22497v2 + A NICER view of the 1.4 solar-mass edge-on pulsar PSR J0614-3329 + https://arxiv.org/abs/2506.14883 + arXiv:2506.14883v2 Announce Type: replace +Abstract: Four neutron star radius measurements have already been obtained by modeling the X-ray pulses of rotation-powered millisecond pulsars observed by the Neutron Star Interior Composition ExploreR (NICER). We report here the radius measurement of PSR J0614-3329 employing the same method with NICER and XMM-Newton data using Bayesian Inference. For all different models tested, including one with unrestricted inclination prior, we retrieve very similar non-antipodal hot regions geometries and radii. For the preferred model, we infer an equatorial radius of $R_{\rm eq}=10.29^{+1.01}_{-0.86}\,$km for a mass of $M=1.44^{+0.06}_{-0.07} \, M_{\odot}$ (median values with equal-tailed $68\%$ credible interval), the latter being essentially constrained from radio timing priors obtained by MeerKAT. A more complex model, fitting the data equally well, resulted in a consistent inferred radius. We find that, for all different models, the pulse emission originates from two hot regions, one at the pole and the other at the equator. The resulting radius constraint is consistent with previous X-ray and gravitational wave measurements of neutron stars in the same mass range. Equation of state inferences, including previous NICER and gravitational wave results, slightly soften the equation of state with PSR J0614$-$3329 included and shift the allowed mass-radius region toward lower radii by $\sim 300\,$m, which is compatible with previous analyses to within less than one standard deviation. + oai:arXiv.org:2506.14883v2 + astro-ph.HE astro-ph.SR - astro-ph.EP - astro-ph.GA - astro-ph.IM - Wed, 10 Dec 2025 00:00:00 -0500 + nucl-th + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - M. \v{Z}erjal (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), C. Dominguez-Tagle (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), N. Vitas (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), N. Sedighi (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), E. L. Mart\'in (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), M. R. Zapatero Osorio (Centro de Astrobiolog\'ia), J. Olivares (Departamento de Inteligencia Artificial, Universidad Nacional de Educaci\'on a Distancia), S. Mu\~noz Torres (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), S. Tsilia (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), J. -Y. Zhang (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), D. Barrado (Centro de Astrobiolog\'ia), V. J. S. B\'ejar (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), H. Bouy (Laboratoire d'Astrophysique de Bordeaux, CNRS and Universit\'e de Bordeaux, All\'ee Geoffroy St. Hilaire, 33165 Pessac, France, Institut universitaire de France), A. Burgasser (Department of Astronomy \& Astrophysics, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA), P. Cruz (Centro de Astrobiolog\'ia), N. Lodieu (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), P. Mas Buitrago (Centro de Astrobiolog\'ia), N. Phan-Bao (Department of Physics, International University, Ho Chi Minh City, Vietnam, Vietnam National University, Ho Chi Minh City, Vietnam), E. Solano (Centro de Astrobiolog\'ia), R. Tata (Ohio University, Physics \& Astronomy Department,1 Ohio University, Athens, OH 45701, USA), B. Goldman (International Space University, 1 rue Jean-Dominique Cassini, 67400 Illkirch-Graffenstaden, France, Universit\'e de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France), A. Mohandasan (Universite Marie et Louis Pasteur, CNRS, Observatoire des Sciences de l'Univers THETA Franche-Comte Bourgogne, Institut UTINAM, Observatoire de Besan\c{c}on, BP 1615, 25010 Besan\c{c}on Cedex, France), C. Reyl\'e (Universite Marie et Louis Pasteur, CNRS, Observatoire des Sciences de l'Univers THETA Franche-Comte Bourgogne, Institut UTINAM, Observatoire de Besan\c{c}on, BP 1615, 25010 Besan\c{c}on Cedex, France), R. L. Smart (INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese, Department of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK), N. Aghanim (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), B. Altieri (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), A. Amara (School of Mathematics and Physics, University of Surrey, Guildford, Surrey, GU2 7XH, UK), S. Andreon (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), N. Auricchio (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), C. Baccigalupi (IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy), M. Baldi (Dipartimento di Fisica e Astronomia, Universit\`a di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), A. Balestra (INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), S. Bardelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), P. Battaglia (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), A. Biviano (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), A. Bonchi (Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy), E. Branchini (Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy, INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), M. Brescia (Department of Physics "E. Pancini", University Federico II, Via Cinthia 6, 80126, Napoli, Italy, INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), J. Brinchmann (Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal, Faculdade de Ci\^encias da Universidade do Porto, Rua do Campo de Alegre, 4150-007 Porto, Portugal), S. Camera (Dipartimento di Fisica, Universit\`a degli Studi di Torino, Via P. Giuria 1, 10125 Torino, Italy, INFN-Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy, INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), G. Ca\~nas-Herrera (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands, Institute Lorentz, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands, Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), V. Capobianco (INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), C. Carbone (INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy), J. Carretero (Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), S. Casas (Institute for Theoretical Particle Physics and Cosmology), M. Castellano (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), G. Castignani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Cavuoti (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy, INFN section of Naples, Via Cinthia 6, 80126, Napoli, Italy), K. C. Chambers (Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA), A. Cimatti (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), C. Colodro-Conde (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain), G. Congedo (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), C. J. Conselice (Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK), L. Conversi (European Space Agency/ESRIN, Largo Galileo Galilei 1, 00044 Frascati, Roma, Italy, ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), Y. Copin (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), F. Courbin (Institut de Ci\`encies del Cosmos, Instituci\'o Catalana de Recerca i Estudis Avan\c{c}ats), H. M. Courtois (UCB Lyon 1, CNRS/IN2P3, IUF, IP2I Lyon, 4 rue Enrico Fermi, 69622 Villeurbanne, France), M. Cropper (Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK), J. -G. Cuby (Canada-France-Hawaii Telescope, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743, USA, Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), A. Da Silva (Departamento de F\'isica, Faculdade de Ci\^encias, Universidade de Lisboa, Edif\'icio C8, Campo Grande, PT1749-016 Lisboa, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal), H. Degaudenzi (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), G. De Lucia (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), C. Dolding (Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK), H. Dole (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), M. Douspis (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), F. Dubath (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), X. Dupac (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), S. Dusini (INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), S. Escoffier (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), M. Farina (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), F. Faustini (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy, Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy), S. Ferriol (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), S. Fotopoulou (School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK), M. Frailis (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), E. Franceschi (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Galeotta (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), K. George (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstrasse 1, 81679 M\"unchen, Germany), B. Gillis (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), C. Giocoli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), P. G\'omez-Alvarez (FRACTAL S.L.N.E., calle Tulip\'an 2, Portal 13 1A, 28231, Las Rozas de Madrid, Spain, ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), J. Gracia-Carpio (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), B. R. Granett (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), A. Grazian (INAF-Osservatorio Astronomico di Padova, Via dell'Osservatorio 5, 35122 Padova, Italy), F. Grupp (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany, Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstrasse 1, 81679 M\"unchen, Germany), S. V. H. Haugan (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), J. Hoar (ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Ca\~nada, Madrid, Spain), W. Holmes (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), F. Hormuth (Felix Hormuth Engineering, Goethestr. 17, 69181 Leimen, Germany), A. Hornstrup (Technical University of Denmark, Elektrovej 327, 2800 Kgs. Lyngby, Denmark, Cosmic Dawn Center), K. Jahnke (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), M. Jhabvala (NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA), E. Keih\"anen (Department of Physics and Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), S. Kermiche (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), A. Kiessling (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), B. Kubik (Universit\'e Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, F-69100, France), K. Kuijken (Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands), M. K\"ummel (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstrasse 1, 81679 M\"unchen, Germany), M. Kunz (Universit\'e de Gen\`eve, D\'epartement de Physique Th\'eorique and Centre for Astroparticle Physics, 24 quai Ernest-Ansermet, CH-1211 Gen\`eve 4, Switzerland), H. Kurki-Suonio (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), Q. Le Boulc'h (Centre de Calcul de l'IN2P3/CNRS, 21 avenue Pierre de Coubertin 69627 Villeurbanne Cedex, France), A. M. C. Le Brun (Laboratoire d'etude de l'Univers et des phenomenes eXtremes, Observatoire de Paris, Universit\'e PSL, Sorbonne Universit\'e, CNRS, 92190 Meudon, France), S. Ligori (INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese), P. B. Lilje (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), V. Lindholm (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), I. Lloro (SKAO, Jodrell Bank, Lower Withington, Macclesfield SK11 9FT, UK), G. Mainetti (Centre de Calcul de l'IN2P3/CNRS, 21 avenue Pierre de Coubertin 69627 Villeurbanne Cedex, France), D. Maino (Dipartimento di Fisica "Aldo Pontremoli", Universit\`a degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy, INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy, INFN-Sezione di Milano, Via Celoria 16, 20133 Milano, Italy), E. Maiorano (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), O. Mansutti (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), O. Marggraf (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), M. Martinelli (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy, INFN-Sezione di Roma, Piazzale Aldo Moro, 2 - c/o Dipartimento di Fisica, Edificio G. Marconi, 00185 Roma, Italy), N. Martinet (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), F. Marulli (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), R. Massey (Department of Physics, Institute for Computational Cosmology, Durham University, South Road, Durham, DH1 3LE, UK), E. Medinaceli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), S. Mei (Universit\'e Paris Cit\'e, CNRS, Astroparticule et Cosmologie, 75013 Paris, France, CNRS-UCB International Research Laboratory, Centre Pierre Bin\'etruy, IRL2007, CPB-IN2P3, Berkeley, USA), Y. Mellier (Institut d'Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France, Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, France), M. Meneghetti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), E. Merlin (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy), G. Meylan (Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique F\'ed\'erale de Lausanne), A. Mora (Aurora Technology for European Space Agency), M. Moresco (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), L. Moscardini (Dipartimento di Fisica e Astronomia "Augusto Righi" - Alma Mater Studiorum Universit\`a di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), R. Nakajima (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), C. Neissner (Institut de F\'isica d'Altes Energies, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), S. -M. Niemi (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands), C. Padilla (Institut de F\'isica d'Altes Energies), S. Paltani (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), F. Pasian (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), K. Pedersen (DARK, Niels Bohr Institute, University of Copenhagen, Jagtvej 155, 2200 Copenhagen, Denmark), W. J. Percival (Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada), V. Pettorino (European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands), S. Pires (Universit\'e Paris-Saclay, Universit\'e Paris Cit\'e, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France), G. Polenta (Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy), M. Poncet (Centre National d'Etudes Spatiales -- Centre spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France), L. A. Popa (Institute of Space Science, Str. Atomistilor, nr. 409 M\u{a}gurele, Ilfov, 077125, Romania), L. Pozzetti (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), F. Raison (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), R. Rebolo (Instituto de Astrof\'isica de Canarias, E-38205 La Laguna, Tenerife, Spain, Consejo Superior de Investigaciones Cientificas, Calle Serrano 117, 28006 Madrid, Spain, Universidad de La Laguna, Dpto. Astrof\'i sica, E-38206 La Laguna, Tenerife, Spain), A. Renzi (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), J. Rhodes (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), G. Riccio (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), E. Romelli (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), M. Roncarelli (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), R. Saglia (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstrasse 1, 81679 M\"unchen, Germany, Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), Z. Sakr (Institut f\"ur Theoretische Physik, University of Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany, Institut de Recherche en Astrophysique et Plan\'etologie, Universit\'e St Joseph, Faculty of Sciences, Beirut, Lebanon), D. Sapone (Departamento de F\'isica, FCFM, Universidad de Chile, Blanco Encalada 2008, Santiago, Chile), B. Sartoris (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstrasse 1, 81679 M\"unchen, Germany, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), J. A. Schewtschenko (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), M. Schirmer (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), P. Schneider (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), A. Secroun (Aix-Marseille Universit\'e, CNRS/IN2P3, CPPM, Marseille, France), G. Seidel (Max-Planck-Institut f\"ur Astronomie, K\"onigstuhl 17, 69117 Heidelberg, Germany), M. Seiffert (Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA), S. Serrano (Institut d'Estudis Espacials de Catalunya, Satlantis, University Science Park, Sede Bld 48940, Leioa-Bilbao, Spain, Institute of Space Sciences), P. Simon (Universit\"at Bonn, Argelander-Institut f\"ur Astronomie, Auf dem H\"ugel 71, 53121 Bonn, Germany), C. Sirignano (Dipartimento di Fisica e Astronomia "G. Galilei", Universit\`a di Padova, Via Marzolo 8, 35131 Padova, Italy, INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), G. Sirri (INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy), L. Stanco (INFN-Padova, Via Marzolo 8, 35131 Padova, Italy), J. Steinwagner (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), P. Tallada-Cresp\'i (Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas, Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra), A. N. Taylor (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK), I. Tereno (Departamento de F\'isica, Faculdade de Ci\^encias, Universidade de Lisboa, Edif\'icio C8, Campo Grande, PT1749-016 Lisboa, Portugal, Instituto de Astrof\'isica e Ci\^encias do Espa\c{c}o, Faculdade de Ci\^encias, Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal), S. Toft (Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen, Jagtvej 128, 2200 Copenhagen, Denmark), R. Toledo-Moreo (Universidad Polit\'ecnica de Cartagena, Departamento de Electr\'onica y Tecnolog\'ia de Computadoras, Plaza del Hospital 1, 30202 Cartagena, Spain), F. Torradeflot (Port d'Informaci\'o Cient\'ifica, Campus UAB, C. Albareda s/n, 08193 Bellaterra, Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas), A. Tsyganov (Centre for Information Technology, University of Groningen, P.O. Box 11044, 9700 CA Groningen, The Netherlands), I. Tutusaus (Institut de Recherche en Astrophysique et Plan\'etologie), L. Valenziano (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy, INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy), J. Valiviita (Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland, Helsinki Institute of Physics, Gustaf H\"allstr\"omin katu 2, University of Helsinki, 00014 Helsinki, Finland), T. Vassallo (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstrasse 1, 81679 M\"unchen, Germany, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), G. Verdoes Kleijn (Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands), A. Veropalumbo (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy, INFN-Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy, Dipartimento di Fisica, Universit\`a di Genova, Via Dodecaneso 33, 16146, Genova, Italy), Y. Wang (Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA), J. Weller (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstrasse 1, 81679 M\"unchen, Germany, Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), A. Zacchei (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy), G. Zamorani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), F. M. Zerbi (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy), E. Zucca (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), J. Mart\'in-Fleitas (Aurora Technology for European Space Agency), V. Scottez (Institut d'Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France, ICL, Junia, Universit\'e Catholique de Lille, LITL, 59000 Lille, France) + 10.3847/1538-4357/ae145d + Lucien Mauviard, Sebastien Guillot, Tuomo Salmi, Devarshi Choudhury, Bas Dorsman, Denis Gonz\'alez-Caniulef, Mariska Hoogkamer, Daniela Huppenkothen, Christine Kazantsev, Yves Kini, Jean-Francois Olive, Pierre Stammler, Anna L. Watts, Melissa Mendes, Nathan Rutherford, Achim Schwenk, Isak Svensson, Slavko Bogdanov, Matthew Kerr, Paul S. Ray, Lucas Guillemot, Isma\"el Cognard, Gilles Theureau - Smooth sailing or ragged climb? -- Increasing the robustness of power spectrum de-wiggling and ShapeFit parameter compression - https://arxiv.org/abs/2504.10578 - arXiv:2504.10578v2 Announce Type: replace -Abstract: The baryonic features in the galaxy power spectrum offer tight, time-resolved constraints on the expansion history of the Universe but complicate the measurement of the broadband shape of the power spectrum, which also contains precious cosmological information. In the context of ShapeFit, the broadband information is compressed into a single parameter, the slope of the power spectrum at the pivot scale, $m$, is sensitive to matter-radiation equality and the baryonic suppression. To calculate this parameter, two steps are necessary: 1) smoothing the power spectrum to remove the baryonic oscillations and 2) calculating the derivative of the power spectrum ratio at the pivot scale. In this work we compare thirteen methods designed to separate the broadband and oscillating components and examine their performance. The systematic uncertainty between different de-wiggling procedures is at most $2$%, depending on the scale. For the obtained slope, we show that the de-wiggling procedures impart large 50% differences, but as long as the theory and data pipelines are consistent, this is of no concern for cosmological inference given the precision of existing and ongoing surveys. However, it still motivates the search for more robust ways of extracting the slope. We show that post-processing the power spectrum ratio before taking the derivative makes the slope values far more robust. We further investigate eleven ways of extracting the slope and highlight the two most successful ones. We derive a systematic uncertainty on the slope $m$ of $\sigma_{m,\mathrm{syst}} = 0.023 |m| + 0.001$ by studying the behavior of the slopes in different cosmologies and the impact in cosmological inference. In cosmologies with a feature in the matter-power spectrum, such as in the early dark energy cosmologies, this systematic uncertainty estimate does not necessarily hold, and further investigation is required. - oai:arXiv.org:2504.10578v2 - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + Localisation and host galaxy identification of new Fast Radio Bursts with MeerKAT + https://arxiv.org/abs/2507.05982 + arXiv:2507.05982v3 Announce Type: replace +Abstract: Accurately localising fast radio bursts (FRBs) is essential for understanding their birth environments and for their use as cosmological probes. Recent advances in radio interferometry, particularly with MeerKAT, have enabled the localisation of individual bursts with arcsecond precision. In this work, we present the localisation of 15 apparently non-repeating FRBs detected with MeerKAT. Two of the FRBs, discovered in 2022, were localised in 8 second images from the projects which MeerTRAP was commensal to, while eight were localised using the transient buffer (TB) pipeline, and another one through SeeKAT, all with arcsecond precision. Four additional FRBs lacked TB triggers and sufficient signal, limiting their localisation only to arcminute precision. For eight of the FRBs in our sample, we identify host galaxies with greater than 90% confidence, and one with 80% confidence, while two FRBs have ambiguous associations. We measured spectroscopic redshifts for six host galaxies, ranging from 0.33 to 0.85, demonstrating MeerKAT's sensitivity to high redshift FRBs. We modelled the spectral energy distributions of host galaxies with sufficient photometric coverage to derive their stellar population and star formation properties. This work represents one of the largest uniform samples of well-localised distant FRBs to date, laying the groundwork for using MeerKAT FRBs as cosmological probes and understand how FRB hosts evolve at high redshift. + oai:arXiv.org:2507.05982v3 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1088/1475-7516/2025/11/029 - Journal of Cosmology and Astroparticle Physics, 2025(11), 029 - Katayoon Ghaemi, Nils Sch\"oneberg, Licia Verde + http://creativecommons.org/licenses/by/4.0/ + 10.1093/mnras/staf2144 + Monthly Notices of the Royal Astronomical Society, Volume 538, Issue 3, pp.1800-1815, 2025 + In\'es Pastor-Marazuela, Alexa C. Gordon, Ben Stappers, Ilya S. Khrykin, Nicolas Tejos, Kaustubh Rajwade, Manisha Caleb, Mayuresh P. Surnis, Laura N. Driessen, Sunil Simha, Jun Tian, J. Xavier Prochaska, Ewan Barr, Sarah Buchner, Wen-Fai Fong, Fabian Jankowski, Lordrick Kahinga, Charles D. Kilpatrick, Michael Kramer, Lluis Mas-Ribas, Joseph Hennawi - Isotropy Test with Quasars Using Method of Smoothed Residuals - https://arxiv.org/abs/2505.07439 - arXiv:2505.07439v2 Announce Type: replace -Abstract: To assess the significance and scale dependence of anomalous large scale modes in the CatWISE quasar data, we generate smoothed number density fields on the sphere and study their extreme values -- maximum, minimum, maximum antipodal difference. By comparing these summary statistics to those obtained from random isotropic realisations of the data, we determine the statistical significance of large scale modes as a function of smoothing scale. We perform our analysis using five different versions of the data -- the original quasar map, the maps after separately subtracting the ecliptic bias and the CMB dipole, the map obtained after subtracting both, and the map after subtracting the ecliptic bias and anomalous dipole inferred in \cite{Secrest2021}. We find that the ecliptic-corrected, CMB dipole-removed map exhibits large scale modes that are in tension with random realisations of the data (p-values $p \lesssim 10^{-4}$), over a wide range of smoothing scales $\pi/8 \leq \delta \leq \pi/2$. The most prominent feature in the data is an under-density in the southern galactic plane at $(b,\ell) = (-31^\circ,78^\circ)$, which reaches its highest statistical significance when smoothed on scales $\delta = \pi/6$ ($p = 1.2 \times 10^{-6}$). Notably, the minima statistics align with the maximum antipodal difference statistics, whereas the maxima do not. This suggests that the observed dipole-like behavior in the data is primarily driven by the under-density in the southern sky. The ecliptic corrected, anomalous dipole subtracted map reduces the significance of any residual anisotropic features, but an under-density in the south sky persists with p-value $p =0.0018$. - oai:arXiv.org:2505.07439v2 + Baryonification: An alternative to hydrodynamical simulations for cosmological studies + https://arxiv.org/abs/2507.07892 + arXiv:2507.07892v2 Announce Type: replace +Abstract: We present an improved baryonification (BFC) model that modifies dark-matter-only $N$-body simulations to generate particle-level outputs for gas, dark matter, and stars. Unlike previous implementations, our approach first splits each simulation particle into separate dark matter and baryonic components, which are then displaced individually using the BFC technique. By applying the hydrostatic and ideal gas equations, we assign pressure and temperature values to individual gas particles. The model is validated against hydrodynamical simulations from the FLAMINGO and TNG suites (which feature varied feedback prescriptions) showing good agreement at the level of density and pressure profiles across a wide range of halo masses. As a further step, we calibrate the BFC model parameters to gas and stellar mass ratio profiles from the hydrodynamical simulations. Based on these calibrations, we baryonify $N$-body simulations and compare the resulting total matter power spectrum suppressions to the ones from the same hydrodynamical simulation. Carrying out this test of the BFC method at each redshift individually, we obtain a 2 percent agreement up to $k=5\,h$/Mpc across all tested feedback scenarios. We also define a reduced, 2+1 parameter BFC model that simultaneously accounts for feedback variations (2 parameters) and redshift evolution (1 parameter). The 2+1 parameter model agrees with the hydrodynamical simulations to better than 2.5 percent over the scales and redshifts relevant for cosmological surveys. Finally, we present a map-level comparison between a baryonified $N$-body simulation and a full hydrodynamical run from the TNG simulation suite. Visual inspection of dark matter, gas, and stellar density fields, along with the integrated pressure map, shows promising agreement. Further work is needed to quantify the accuracy at the level of observables. + oai:arXiv.org:2507.07892v2 astro-ph.CO - hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Akhil Antony, Stephen Appleby, William L Matthewson, Arman Shafieloo + Aurel Schneider, Michael Kova\v{c}, Jozef Bucko, Andrina Nicola, Robert Reischke, Sambit K. Giri, Romain Teyssier, Tilman Tr\"oster, Alexandre Refregier, Matthieu Schaller, Joop Schaye - Shapes and orientations of massive halos in the statistically anisotropic universe - https://arxiv.org/abs/2505.15082 - arXiv:2505.15082v2 Announce Type: replace -Abstract: We investigate how statistical anisotropy (SA) in matter distributions affects the distributions of shapes and orientations of cluster-sized halos, using cosmological $N$-body simulations that incorporate SA. While the three-dimensional halo shape parameters show little dependence on SA, we find that halo orientations are significantly influenced, with halos tending to align either perpendicular or parallel to the SA direction. This SA-induced alignment becomes more prominent for more massive halos. We also study other vector quantities associated with the dynamics of halos, such as bulk velocity and angular momentum vectors. We find that their dependences on the SA are smaller than those of the orientation vectors. Our findings suggest that observational measurements of projected halo shapes derived from galaxy cluster-galaxy lensing could provide a novel probe of SA in the universe. - oai:arXiv.org:2505.15082v2 - astro-ph.CO - gr-qc - hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 + Transient QPOs of Fermi-LAT blazars with Linearly Multiplicative Oscillations + https://arxiv.org/abs/2507.13906 + arXiv:2507.13906v3 Announce Type: replace +Abstract: We present a study on the detection and characterization of transient quasi-periodic oscillations (QPOs) in the $\gamma$-ray emission of blazars 4C +31.03, MG1 J123931+0443, and PKS 1622$-$253. Using light curves derived from \textit{Fermi} Large Area Telescope data, we investigate oscillatory patterns characterized by periodic multiplicative amplitudes that vary linearly over time. By segmenting the light curves into increasing and decreasing trends, we analyze each segment independently, allowing for precise measurements of both the periodicity and long-term variations. To interpret these QPOs, we explore various theoretical scenarios that could explain their origin and underlying physical mechanisms. The variability observed in 4C~+31.03 is more consistent with a stochastic process, whereas the periods estimated for MG1~J123931+0443 and PKS~1622$-$253 align with the precessional dynamics expected from binary supermassive black hole systems. However, the current results remain tentative and do not allow for a definitive conclusion. + oai:arXiv.org:2507.13906v3 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Shogo Masaki, Yurino Mizuguchi, Shohei Saga, Shuichiro Yokoyama + http://creativecommons.org/licenses/by/4.0/ + 10.33232/001c.154123 + P. Penil, J. Otero-Santos, A. Circiello, A. Banerjee, S. Buson, A. Rico, M. Ajello, S. Adhikari - Core Collapse Beyond the Fluid Approximation: The Late Evolution of Self-Interacting Dark Matter Halos - https://arxiv.org/abs/2505.15903 - arXiv:2505.15903v2 Announce Type: replace -Abstract: We show that the gravothermal collapse of self-interacting dark matter (SIDM) halos can deviate from local thermodynamic equilibrium. As a consequence, the self-similar evolution predicted by the commonly adopted conducting fluid model can be altered or broken. Our results are obtained using a novel, efficient kinetic solver called KiSS-SIDM for tracing the gravothermal evolution based on the Direct Simulation Monte Carlo (DSMC) framework. In the long mean free path stage, the code is a viable alternative to the fluid model, yet requires no calibration parameters. Further, this method enables a fully kinetic treatment well into the late, short mean free path, stage of the collapse. We apply the method to a canonical case with isotropic, velocity independent scattering. We find that although a fluid treatment is appropriate deep in the short mean free path core, departures from local thermodynamic equilibrium develop in the intermediate mean free path region bounding the core, which modify the late-time evolution. KiSS-SIDM is publicly available at https://gitlab.com/Socob/KiSS-SIDM. - oai:arXiv.org:2505.15903v2 - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + The superclouds of the local Milky Way + https://arxiv.org/abs/2507.14883 + arXiv:2507.14883v2 Announce Type: replace +Abstract: Recent 3D dust maps of the local Milky Way are revolutionizing our understanding of the Sun's Galactic neighborhood, bringing much-needed insight into the large-scale organization of the interstellar medium. Focusing on the largest scales in $\textit{Gaia}$-based 3D dust maps, we find a pattern of seven highly elongated, mostly parallel structures in the local $5\,\mathrm{kpc}^2$, five of which were previously unknown. These structures show pitch angles of $33.5 \pm 4.0 ^\circ$, and masses ranging from $10^5$ to $10^6$ $\mathrm{M}_\odot$. We refer to these structures as superclouds. Nearly all known star-forming regions in the solar neighborhood lie within the superclouds, primarily along their central axes, supporting the idea that they are precursors to giant molecular clouds. All but one of the seven superclouds show an underlying undulation, indicating that this is not a property unique to the Radcliffe wave. We find that while the superclouds have line masses that vary by about a factor of four, their volume densities vary by about $10\%$ only. This suggests that superclouds self-regulate their physical sizes and internal structure to maintain pressure equilibrium with their environment. These findings establish a new framework for understanding how large-scale Galactic structures shape the conditions for star formation in the solar vicinity, and likely in galaxies like the Milky Way. + oai:arXiv.org:2507.14883v2 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1103/2ycz-3fvv - PRL 135 (2025), 221001 - James Gurian, Simon May + http://creativecommons.org/licenses/by/4.0/ + Lilly A. Kormann, Jo\~ao Alves, Michelangelo Pantaleoni Gonz\'alez, Cameren Swiggum, Torsten A. En{\ss}lin, Gordian Edenhofer - Bayesian luminosity function estimation in multi-depth datasets with selection effects: A case study for $3<z<5$ Lyman $\alpha$ emitters - https://arxiv.org/abs/2506.10083 - arXiv:2506.10083v2 Announce Type: replace -Abstract: We present a hierarchical Bayesian framework designed to infer the luminosity function of any class of object by jointly modelling data from multiple surveys with varying depth, completeness, and sky coverage. Our method explicitly accounts for selection effects and measurement uncertainties (e.g. in luminosity) and can be generalized to any extensive quantity, such as mass. We validated the model using mock catalogues; from this we determined that deep data reaching $\gtrsim 1.5$ dex below a characteristic luminosity ($\tilde{L}^\star$) are essential to reducing biases at the faint end ($\lesssim 0.1$ dex) and that wide-area data help constrain the bright end. As a proof of concept, we considered a combined sample of 1176 Lyman $\alpha$ emitters at redshift $3 < z < 5$ drawn from several MUSE surveys, ranging from ultra-deep ($\gtrsim 90$ hr) and narrow ($\lesssim 1$ arcmin$^2$) fields to shallow ($\lesssim 5$ hr) and wide ($\gtrsim 20$ arcmin$^2$) fields. With this complete sample, we constrain the luminosity function parameters $\log(\Phi^\star/\mathrm{Mpc^{-3}}) = -2.86^{+0.15}_{-0.17}$, $\log(L^\star/\mathrm{erg\,s^{-1}}) = 42.72^{+0.10}_{-0.09}$, and $\alpha = -1.81^{+0.09}_{-0.09}$, where the uncertainties represent the $90\%$ credible intervals. These values are in agreement with the results of studies based on gravitational lensing that reach $\log(L/\mathrm{erg\,s^{-1}}) \approx 41$, although differences in the faint-end slope underscore how systematic errors are starting to dominate. In contrast, wide-area surveys represent the natural extension needed to constrain the brightest Lyman $\alpha$ emitters [$\log(L/\mathrm{erg\,s^{-1}}) \gtrsim 43$], where statistical uncertainties still dominate. - oai:arXiv.org:2506.10083v2 + No Metallicity Preference in Fast Radio Burst Host Galaxies + https://arxiv.org/abs/2508.07688 + arXiv:2508.07688v2 Announce Type: replace +Abstract: Fast radio bursts (FRBs) are millisecond-duration extragalactic radio transients of unknown origin, and studying their host galaxies could offer clues to constrain progenitor models. Among host properties, gas-phase metallicity is a key factor influencing stellar evolution and transient productions. We analyze the largest uniformly selected sample of FRB host galaxies, measuring oxygen abundances (12+log(O/H)=8.04-8.85) for 31 hosts at redshifts z=0.04-0.98, using consistent emission-line diagnostics. Using a volume-limited subsample, we compare the distributions of stellar mass, star formation rate (SFR), and metallicity to a control sample of star-forming galaxies selected by the same criteria. We find that FRB host galaxies span a wide metallicity range and are broadly consistent with the SFR-weighted mass-metallicity relation of star-forming galaxies. We find no clear lower metallicity bound, suggesting that FRB progenitors can form in any metallicity environment through channels largely insensitive to metal abundance. Encouragingly, this implies FRBs can arise even in low-metallicity, high-redshift galaxies, supporting their potential as probes of matter distribution across cosmic time. Additionally, we find marginal ($\sim$2$\sigma$) evidence for a -0.09\pm0.04 dex metallicity offset from the fundamental metallicity relation. Despite model uncertainties, if real, this offset likely reflects suppressed SFRs at fixed mass and metallicity rather than metal deficiency. Similar offsets are observed in local post-merger galaxies and may reflect a post-starburst phase following galaxy interactions. Such systems may host FRB progenitors formed during the starburst that produce FRBs after a 100-500 Myr delay, broadly consistent with observed delay-time distributions, although further data are needed to confirm this interpretation. + oai:arXiv.org:2508.07688v2 + astro-ph.HE astro-ph.GA - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1051/0004-6361/202555898 - A&A 704, A201 (2025) - Davide Tornotti, Matteo Fossati, Michele Fumagalli, Davide Gerosa, Lorenzo Pizzuti, Fabrizio Arrigoni Battaia + Shotaro Yamasaki, Tetsuya Hashimoto, Haruka Kusakabe, Tomotsugu Goto - Testing stellar yield prescriptions in OMEGA+: Implications for rising sodium abundances in young thick disc stars - https://arxiv.org/abs/2506.17711 - arXiv:2506.17711v2 Announce Type: replace -Abstract: We recently identified an upturn in [Na/Fe] for the population of Solar-type stars in the Galactic young thick disc ($-0.3 < \mathrm{[Fe/H]} < +0.3$) at super-Solar metallicity in data from the GALactic Archaeology with HERMES (GALAH) survey. In this work, we investigate the origin of this unexplained sodium enrichment ([Na/Fe] $\approx 0$--$0.6$~dex) using the OMEGA$+$ galactic chemical evolution code. We explore the rise of [Na/Fe] using four combinations of nucleosynthetic yields from the literature, considering contributions from core-collapse supernovae, asymptotic giant branch stars, and Type~Ia supernovae. Our analysis focuses on two possible drivers of the Na enhancement: a metallicity-dependent increase in Na production from core-collapse supernovae at super-Solar metallicities, and enrichment from metal-rich AGB stars. We adopt two sets of Type~Ia supernova yields, one assuming exclusively Chandrasekhar-mass explosions and the other assuming only sub-Chandrasekhar-mass explosions. We find that the assumed Type~Ia explosion scenario has little influence on the resulting [Na/Fe] evolution, and that all chemical evolution models tested fail to reproduce the observed Na enrichment in the young thick-disc population at super-Solar metallicity. Our results suggest a possible ``under-pollution effect'' by Type~Ia supernovae -- the dominant producers of iron -- in the Solar-type stellar population of the Galactic disc. These findings provide a step toward understanding the origin of the anomalous sodium enrichment at super-Solar metallicities in the Galactic disc. - oai:arXiv.org:2506.17711v2 + Bayesian Inference of Gravity through Realistic 3D Modeling of Wide Binary Orbits: General Algorithm and a Pilot Study with HARPS Radial Velocities + https://arxiv.org/abs/2508.11996 + arXiv:2508.11996v4 Announce Type: replace +Abstract: When 3D relative displacement $\mathbf{r}$ and velocity $\mathbf{v}$ between the pair in a gravitationally-bound system are precisely measured, the six measured quantities at one phase can allow elliptical orbit solutions at a given gravitational parameter $G$. Due to degeneracies between orbital-geometric parameters and $G$, individual Bayesian inferences and their statistical consolidation are needed to infer $G$ as recently suggested by a Bayesian 3D modeling algorithm. Here I present a fully general Bayesian algorithm suitable for wide binaries with two (almost) exact sky-projected relative positions (as in the Gaia data release 3) and the other four sufficiently precise quantities. Wide binaries meeting the requirements of the general algorithm to allow for its full potential are rare at present, largely because the measurement uncertainty of the line-of-sight (radial) separation is usually larger than the true separation. As a pilot study, the algorithm is applied to 32 Gaia binaries for which precise HARPS radial velocities are available. The value of $\Gamma \equiv \log_{10}\sqrt{G/G_{\rm N}}$ (where $G_{\rm N}$ is Newton's constant) is $-0.002_{-0.018}^{+0.012}$ supporting Newton for a combination of 24 binaries with Newtonian acceleration $g_{\rm N}>10^{-9}$m\,s$^{-2}$, while it is $\Gamma=0.134_{-0.036}^{+0.056}$ (thermal prior on eccentricity) or $0.115_{-0.028}^{+0.048}$ (flat prior) for 8 binaries with $g_{\rm N}<10^{-9}$m\,s$^{-2}$ representing $>3.7\sigma$ discrepancy with Newton. Moreover, the inferred orbital true anomalies clearly favor modified gravity over Newton with the difference of Bayesian information criterion $>10$. The pilot study demonstrates the potential of the algorithm in measuring and testing gravity at low acceleration with future samples of wide binaries. + oai:arXiv.org:2508.11996v4 astro-ph.GA - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + gr-qc + hep-th + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - 10.1093/mnras/staf2079 - Evans K. Owusu (School of Science, University of New South Wales Canberra, Australia Defence Force Academy, ACT, Australia, ARC Centre of Excellence for All-Sky Astrophysics in 3 Dimensions, Max-Planck-Institut f\"ur Astronomie, Heidelberg, Germany, Heidelberger Institut f\"ur Theoretische Studien, Heidelberg, Germany), Ashley J. Ruiter (School of Science, University of New South Wales Canberra, Australia Defence Force Academy, ACT, Australia, ARC Centre of Excellence for All-Sky Astrophysics in 3 Dimensions, Max-Planck-Institut f\"ur Astronomie, Heidelberg, Germany, Heidelberger Institut f\"ur Theoretische Studien, Heidelberg, Germany, Mathematical Sciences Institute, Australian National University, Canberra, ACT, Australia), Alex J. Kemp (Institute of Astronomy), Sven Buder (ARC Centre of Excellence for All-Sky Astrophysics in 3 Dimensions, Research School of Astronomy and Astrophysics, Australian National University, ACT, Australia), Ivo R. Seitenzahl (Heidelberger Institut f\"ur Theoretische Studien, Heidelberg, Germany, Mathematical Sciences Institute, Australian National University, Canberra, ACT, Australia, Research School of Astronomy and Astrophysics, Australian National University, ACT, Australia), Nicolas Rodriguez-Segovia (School of Science, University of New South Wales Canberra, Australia Defence Force Academy, ACT, Australia), R. Pakmor (Max Planck Institute for Astrophysics, Garching, Germany), Giulia C. Cinquegrana (ARC Centre of Excellence for All-Sky Astrophysics in 3 Dimensions, School of Physics & Astronomy, Monash University, Clayton, VIC, Australia), Nicholas Storm (Max-Planck-Institut f\"ur Astronomie, Heidelberg, Germany, Heidelberg University, Heidelberg, Germany), Philipp Eitner (Max-Planck-Institut f\"ur Astronomie, Heidelberg, Germany, Heidelberg University, Heidelberg, Germany), Maria Bergemann (Max-Planck-Institut f\"ur Astronomie, Heidelberg, Germany) + Kyu-Hyun Chae - Hiding behind a curtain of dust: Gas and dust properties of an ultra-luminous strongly-lensed z = 3.75 galaxy behind the Milky Way disk - https://arxiv.org/abs/2506.21283 - arXiv:2506.21283v3 Announce Type: replace -Abstract: We present a detailed analysis of J154506, a strongly lensed submillimeter galaxy behind the Lupus-I molecular cloud, and characterisation of its physical properties using a combination of new and archival data, including VLT/MUSE and FORS2 optical data. We identify two high-significance (SNR>5) emission lines at 97.0 and 145.5 GHz, corresponding to CO(4-3) and CO(6-5), respectively in the spectral scans from the Atacama Compact Array and the Large Millimeter Telescope and the [CII] 158~$\mu$m fine-structure line at 400~GHz using the Atacama Pathfinder Experiment. These detections yield a spectroscopic redshift of $z_{\rm{spec}}=3.7515\pm0.0005$. We also report the detection of [CI], HCN(4-3), and two H$_2\rm{O}^+$ transitions, further confirming the redshift and providing insights into J154506's physical properties. By modeling sub-arcsecond resolution (0.75) ALMA Band 6 and 7 continuum data in the uv-plane, we derive an average magnification factor of $6.0\pm0.4$ and our analysis reveals a relatively cold dust (37K) in a starburst ($\sim900~\rm{M}_{\odot}yr^{-1}$) galaxy with a high intrinsic dust mass ($\sim2.5\times10^{9}~\rm{M}_{\odot}$) and infrared (IR) luminosity ($\sim6\times10^{12}~\rm{L}_{\odot}$). The non-local thermodynamic equilibrium radiative transfer modeling of the joint dust SED and CO line excitation suggests the dust continuum emission is primarily associated with relatively diffuse regions with molecular gas densities of $10^2-10^4\rm{cm}^{-3}$, rather than compact, high-pressure environments typical of extreme starbursts or AGNs. This is supported by the close-to-unity ratio between the dust and gas kinetic temperatures, which argues against highly energetic heating mechanisms. The CO excitation ladder peaks close to CO(5-4) and is dominated by slightly denser molecular gas. - oai:arXiv.org:2506.21283v3 + Chemical enrichment of metal-poor stars orbiting massive black hole companions + https://arxiv.org/abs/2508.14163 + arXiv:2508.14163v3 Announce Type: replace +Abstract: There are millions of undetected black holes wandering through our galaxy. Observatories like {\it Chandra}, LIGO, and more recently, {\it Gaia}, have provided valuable insights into the configurations of these elusive objects when residing in binary systems. Motivated by these advances, we study, for the first time, the enhanced accretion of metals from the interstellar medium (ISM) onto low-mass companions in binary systems with highly unequal mass ratios, utilizing a series of hydrodynamical simulations. Our study demonstrates that a stellar companion's metal accretion history from the ISM alone, from its formation to the present, can significantly influence its surface abundances, especially when enhanced by a massive black hole companion. However, this effect is likely only measurable in stars that are still in the main sequence. Once a stellar companion evolves off the main sequence, similar to what has been observed with the {\it Gaia} BH3 companion, the initial dredge-up process are likely to erase any excess surface abundance resulting from the metals that were accreted. As we discover more unequal mass ratio binary systems, it is crucial to understand how the observed metallicity of sun-like companions may differ from their birth metallicity, especially if they are not yet evolved. + oai:arXiv.org:2508.14163v3 + astro-ph.SR astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Bel\'en Alcalde Pampliega, Kevin C. Harrington, Aristeidis Amvrosiadis, Manuel Aravena, Min S. Yun, Hugo Messias, Antonio Hern\'an-Caballero, Leindert Boogaard, Axel Wei{\ss}, Benjamin Beauchesne, Alejandro Santamar\'ia-Miranda, Monica Ivette Rodriguez, Eric Jim\'enez-Andrade, Manuel Solimano, James Lowenthal, Pascale Hibon, Patrick Kamieneski, Daniel Wang, Amit Vishwas, Brenda Frye, Jorge Gonz\'alez-Lopez, Chentao Yang, Yiqing Song, Meghana Killi + http://creativecommons.org/licenses/by-sa/4.0/ + Alejandra Rosselli-Calderon, Julia Stewart, Sijing Shen, Sukanya Chakrabarti, Melinda Soares-Furtado, Enrico Ramirez-Ruiz - Thermochemical models of outer core convection with heterogeneous core-mantle boundary heat flux - https://arxiv.org/abs/2507.03538 - arXiv:2507.03538v2 Announce Type: replace -Abstract: Thermochemical convection in Earth's outer core is driven by the crystallisation of the inner core that releases latent heat and light elements. A key question in core dynamics is whether a stable layer exists just below the core-mantle boundary. Recent core convection simulations, accounting for CMB heterogeneities, propose locally stable regions (or regional inversion lenses, RILs) rather than a global layer, allowing both stable and unstable regions to coexist. In this study, we consider a suite of numerical simulations of thermal, chemical, and thermochemical convection models focussed on Ekman number ($E=10^{-5}$) with thermal and chemical flux Rayleigh numbers $\widetilde{Ra}_T=30-4000$ and $\widetilde{Ra}_C=30-100000$, and thermal and chemical Prandtl numbers $Pr_T=1$ and $Pr_\xi=10$. Analysis of purely chemical models reveals light element accumulation (LEA) below the CMB, resulting in either locally stable regions near the poles or global layers, depending on the strength of chemical forcing. These chemically stratified regions persist in our thermochemical models even if the thermal field is fully destabilising. The addition of a heterogeneous CMB heat flux leads to the formation of RILs driven by thermal stratification. Stable regions in these thermochemical models have varying locations, properties, and morphologies depending on whether thermal or chemical convection dominates. In the investigated parameter range, these RILs are O(100 km) thick, and their strength and thickness generally increase with the strength of thermal driving; they are comparatively less sensitive to the strength of chemical driving. Our simulations reveal a diverse range of possible stable regions and/or a global layer at the top of Earth's core, with a seismically plausible range of thickness and strength, which may also have a signature in geomagnetic observations. - oai:arXiv.org:2507.03538v2 + The mid-infrared spectrum of $\beta$ Pictoris b. First VLTI/MATISSE interferometric observations of an exoplanet + https://arxiv.org/abs/2508.18366 + arXiv:2508.18366v2 Announce Type: replace +Abstract: Few spectra of directly-imaged exoplanets have been obtained in the mid-infrared (> 3 $\mu$m). This region is particularly rich in molecular spectral signatures, whose measurements can help recover atmospheric parameters and provide a better understanding of giant planet formation and atmospheric dynamics. In the past years, exoplanet interferometry with the VLTI/GRAVITY instrument has provided medium-resolution spectra of a dozen substellar companions in the near infrared. The 100-meter interferometric baselines allow for the stellar and planetary signals to be efficiently disentangled at close angular separations (< 0.3''). We aim to extend this technique to the mid-infrared using MATISSE, the VLTI's mid-infrared spectro-interferometer. We take advantage of the fringe tracking and off-axis pointing capabilities recently brought by the GRA4MAT upgrade. Using this new mode, we observed the giant planet $\beta$ Pictoris b in L and M bands (2.75-5 $\mu$m) at a spectral resolution of 500. We developed a method to correct chromatic dispersion and non-common paths effects in the fringe phase and modelled the planet astrometry and stellar contamination. We obtained a high-signal-to-noise spectrum of $\beta$ Pictoris b, showing the planet continuum in L (for the first time) and M bands, which contains broad absorption features of H$_2$O and CO. In conjunction with a new GRAVITY spectrum, we modelled it with the ForMoSA nested sampling tool and the Exo-REM grid of atmospheric models, and found a solar carbon-to-oxygen ratio in the planet atmosphere. This study opens the way to the characterization of fainter and closer-in planets with MATISSE, which could complement the JWST at angular separations too close for it to obtain exoplanet spectra. Starting in 2025, the new adaptive optics system brought by the GRAVITY+ upgrade will further extend the detection limits of MATISSE. + oai:arXiv.org:2508.18366v2 astro-ph.EP - physics.geo-ph - Wed, 10 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Souvik Naskar, Jonathan E. Mound, Christopher J. Davies, Andrew T. Clarke - - - Robust Extraction of Global 21 cm Spectrum from Experiments with a Chromatic Beam Based on Physics-Motivated Error Modeling - https://arxiv.org/abs/2507.13102 - arXiv:2507.13102v3 Announce Type: replace -Abstract: The extraction of the sky-averaged 21 cm signal from Cosmic Dawn and the Epoch of Reionization faces significant challenges. The bright and anisotropic Galactic foreground, which is 4 - 5 orders of magnitude brighter than the 21 cm signal, when convolved with the inevitably chromatic beam, introduces additional spectral structures that can easily mimic the real 21 cm signal. In this paper, we investigate the signal extraction for a lunar-orbit experiment, where the antenna moves fast in orbit and data from multiple orbits have to be used. We propose a physics-motivated and correlated modeling of both the foreground and the measurement errors. By dividing the sky into multiple regions according to the spectral index distribution and accounting for the full covariance of modeling errors, we jointly fit both the foreground and the 21 cm signal using simulated data for the Discovering the Sky at the Longest wavelength lunar orbit experiment. This method successfully extracts the 21 cm signals of various amplitudes from the simulated data even for a testing antenna with a relatively high level of chromaticity. This approach, which is robust against moderate beam chromaticity, significantly relaxes the stringent design and manufacturing requirements for the antenna, offering a practical solution for future 21 cm global signal experiments either on the ground or in space. - oai:arXiv.org:2507.13102v3 astro-ph.IM - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.3847/1538-4357/ae25ee - Haoran Li, Furen Deng, Meng Zhou, Yidong Xu, Xuelei Chen + 10.1051/0004-6361/202453323 + A&A 704, A182 (2025) + M. Houll\'e, F. Millour, P. Berio, J. Scigliuto, S. Lacour, B. Lopez, F. Allouche, J. -C. Augereau, D. Blain, M. Bonnefoy, M. Carbillet, G. Chauvin, J. Leftley, A. Matter, J. Milli, P. Molli\`ere, E. Nasedkin, M. Nowak, P. Palma-Bifani, \'E. Pantin, P. Priolet, M. Ravet, J. Woillez, W. Balmer, P. Boley, V. G\'amez Rosas, J. H. Girard, X. Haubois, S. Hinkley, M. Hogerheijde, W. Jaffe, J. Kammerer, L. Kreidberg, O. Lai, S. Lagarde, A. Labdon, J. -B. Le Bouquin, A. Meilland, A. M\'erand, C. Paladini, R. Petrov, E. Rickman, Th. Rivinius, S. Robbe-Dubois, R. van Boekel, J. Varga, A. Vigan, J. J. Wang, G. Weigelt - Transient QPOs of Fermi-LAT blazars with Linearly Multiplicative Oscillations - https://arxiv.org/abs/2507.13906 - arXiv:2507.13906v2 Announce Type: replace -Abstract: We present a study on the detection and characterization of transient quasi-periodic oscillations (QPOs) in the $\gamma$-ray emission of blazars 4C +31.03, MG1 J123931+0443, and PKS 1622$-$253. Using light curves derived from \textit{Fermi} Large Area Telescope data, we investigate oscillatory patterns characterized by periodic multiplicative amplitudes that vary linearly over time. By segmenting the light curves into increasing and decreasing trends, we analyze each segment independently, allowing for precise measurements of both the periodicity and long-term variations. To interpret these QPOs, we explore various theoretical scenarios that could explain their origin and underlying physical mechanisms. The variability observed in 4C~+31.03 is more consistent with a stochastic process, whereas the periods estimated for MG1~J123931+0443 and PKS~1622$-$253 align with the precessional dynamics expected from binary supermassive black hole systems. However, the current results remain tentative and do not allow for a definitive conclusion. - oai:arXiv.org:2507.13906v2 + Possible Coronal Geometry in the Hard and Soft State of Black Hole X-ray Binaries from MONK Simulations + https://arxiv.org/abs/2508.21511 + arXiv:2508.21511v2 Announce Type: replace +Abstract: Understanding the coronal geometry in different states of black hole X-ray binaries is important for more accurate modeling of the system. However, it is difficult to distinguish different geometries by fitting the observed Comptonization spectra. In this work, we use the Monte Carlo ray-tracing code MONK to simulate the spectra for three simple corona toy models widely proposed in observational studies: sandwich, spherical, and lamppost, varying their optical depth and size (height). By fitting the simulated NuSTAR observations with the simplcut*kerrbb model, we infer the possible parameter space for the hard state and soft state of different coronal geometries. The influence of the disk inclination angle, black hole spin and coronal temperature is discussed. We find that in the lamppost model, if we exclude the case of a very extended corona, the disk emission is always dominant, making the lamppost geometry incompatible with the hard state. While the sandwich and spherical models can produce similar spectra in both the hard and soft states, the simulated IXPE polarimetric spectra show the potential to break this degeneracy. Geometrical effects arising from the limited size of the corona become evident in lower-spin black holes and affect the spectral fitting, where the larger ISCO reduces the corona coverage of the inner disk. + oai:arXiv.org:2508.21511v2 astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - P. Penil, J. Otero-Santos, A. Circiello, A. Banerjee, S. Buson, A. Rico, M. Ajello, S. Adhikari - - - Assessing Universal Relations for Rapidly Rotating Neutron Stars: Insights from an Interpretable Deep Learning Perspective - https://arxiv.org/abs/2508.05850 - arXiv:2508.05850v2 Announce Type: replace -Abstract: Relations between stellar properties independent of the nuclear equation of state offer profound insights into neutron star physics and have practical applications in data analysis. Commonly, these relations are derived from utilizing various realistic nuclear cold hadronic, hyperonic, and hybrid EoS models, each of which should obey the current constraints and cover a wide range of stiffnesses. Concurrently, the field of multimessenger astronomy has been significantly enhanced by the advent of gravitational wave astronomy, which increasingly incorporates deep learning techniques and algorithms. At the same time, X-ray spectral data from NICER based on known pulsars are available, and additional observations are expected from upcoming missions. In this study, we revisit established universal relations, introduce new ones, and reassess them using a feed-forward neural network as a regression model. More specifically, we mainly propose ``deep'' EoS-insensitive hypersurface relations for rapidly rotating compact objects between several of the star's global parameters, which achieve an accuracy of within $1\%$ in most cases, with only a small fraction of investigated models exceeding this threshold. While analytical expressions can be used to represent some of these relations, the neural network approach demonstrates superior performance, particularly in complex regions of the parameter space. Furthermore, we use the SHapley Additive exPlanations (SHAP) method to interpret the suggested network's predictions, since is based on a strong theoretical framework inspired by the field of cooperative Game Theory. Most importantly, these highly accurate universal relations empowered with the interpretability description could be used in efforts to constrain the high-density equation of state in neutron stars, with the potential to enhance our understanding as new observables emerge. - oai:arXiv.org:2508.05850v2 - astro-ph.HE - gr-qc - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Grigorios Papigkiotis, Georgios Vardakas, Nikolaos Stergioulas + 10.3847/1538-4357/ae1a6e + Astrophys.J. 995: 124 (2025) + Ningyue Fan, Cosimo Bambi, James F. Steiner, Wenda Zhang - The Mass of Cosmic Rays of Ultra High Energy - https://arxiv.org/abs/2508.11378 - arXiv:2508.11378v2 Announce Type: replace -Abstract: A review of several analyses is presented that forces the conclusion that the mass composition of the highest-energy cosmic rays is not proton-dominated. This deduction, combined with the use of a modern hadronic interaction model, should lead to a re-evaluation of the energy spectrum reported by the Telescope Collaboration that may well bring that measurement, and the corresponding one from the Pierre Auger Observatory, into better agreement. - oai:arXiv.org:2508.11378v2 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Taking the Weight Off: Mitigating Parameter Bias from Catastrophic Outliers in 3$\times$2pt Analysis + https://arxiv.org/abs/2509.08052 + arXiv:2509.08052v2 Announce Type: replace +Abstract: Stage IV cosmological surveys will map the universe with unprecedented precision, reducing statistical uncertainties to levels where unmodelled systematics can significantly bias inference. In particular, photometric redshift (photo-z) errors and intrinsic alignments (IA) must be robustly accounted for to ensure accurate inference of cosmological parameters. The increasing depth of Stage IV surveys exacerbates these challenges by producing low signal-to-noise galaxy populations prone to inaccurate photo-z measurements. Catastrophically misidentified redshifts are especially problematic for 3$\times$2pt inferences that combine weak lensing and galaxy clustering information. We demonstrate that even modest outlier fractions (e.g. 5%) can lead to substantial biases in cosmological parameter estimates: up to 1.8${\sigma}$ in ${\Omega}_M$ and ${\sigma}_8$, and over 8${\sigma}$ in the IA redshift evolution parameter ${\eta}$. To address this, we introduce a flexible weighting scheme at the likelihood level that down-weights the most contamination-sensitive elements of the data vector during inference. This method mitigates biases without inflating the parameter space, reducing cosmological parameter biases to below 1${\sigma}$ without substantially degrading constraining power. Our approach offers a practical solution for future analyses, enabling robust cosmological inference in the presence of catastrophic redshift errors. + oai:arXiv.org:2509.08052v2 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - A A Watson + Carolyn McDonald Mill, C. Danielle Leonard, Markus Michael Rau, Cora Uhlemann, Shahab Joudaki - Hot, cold, and multi-component accretion flows around supermassive black hole binaries - https://arxiv.org/abs/2508.11748 - arXiv:2508.11748v2 Announce Type: replace -Abstract: We develop a model for supermassive black hole binaries (SMBHBs) accreting below their Eddington limit, focusing on systems where hot, advection-dominated flows become viable. We specifically explore the spectral appearance of multi-component accretion flows where the solution can independently transition between cold, thin disks and hot, advection-dominated torii depending on the local accretion rate. Using a three-disk model, we compute spectral energy distributions for four possible accretion configurations and assess their observational signatures, including which frequencies might reflect variability at the binary orbital period. The spectral modeling reveals that binary accretion can self-consistently account for many of the properties of standard AGN, while the variability analysis shows that hydrodynamic modulation at the binary period is most likely in the thermal emission and low-frequency synchrotron components. Doppler boosting of emitting material bound to a single binary component would also induce periodic variability. We apply our model to the SMBHB candidate PG1302-102 and demonstrate that a mixed-component accretion state (plus a jet feature) can self-consistently capture the observed broadband spectrum. Our model offers a framework for interpreting candidate SMBHBs and motivates future multi-wavelength follow-up of potential multi-messenger sources, as well as more detailed future modeling of multi-component binary accretion. - oai:arXiv.org:2508.11748v2 - astro-ph.HE - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Precise Constraints on the Energy Budget of WASP-121 b from its JWST NIRISS/SOSS Phase Curve + https://arxiv.org/abs/2509.09760 + arXiv:2509.09760v2 Announce Type: replace +Abstract: Ultra-hot Jupiters exhibit day-to-night temperature contrasts upwards of 1000 K due to competing effects of strong winds, short radiative timescales, magnetic drag, and H2 dissociation/recombination. Spectroscopic phase curves provide critical insights into these processes by mapping temperature distributions and constraining the planet's energy budget across different pressure levels. Here, we present the first NIRISS/SOSS phase curve of an ultra-hot Jupiter, WASP-121 b. The instrument's bandpass [0.6 - 2.85 micron] captures an estimated 50-83% of the planet's bolometric flux, depending on orbital phase, allowing for unprecedented constraints on the planet's global energy budget; previous measurements with HST/WFC3 and JWST/NIRSpec/G395H captured roughly 20% of the planetary flux. Accounting for the unobserved regions of the spectrum, we estimate effective day and nightside temperatures of T_day = 2717 +/- 17 K and T_night = 1562 +/- 19 K corresponding to a Bond albedo of A_B = 0.277 +/- 0.016 and a heat recirculation efficiency of epsilon = 0.246 +/- 0.014. Matching the phase-dependent effective temperature with energy balance models yields a similar Bond albedo of 0.3 and a mixed layer pressure of 1 bar consistent with photospheric pressures, but unexpectedly slow winds of 0.2 km/s, indicative of inefficient heat redistribution. The shorter optical wavelengths of the NIRISS/SOSS Order 2 yield a geometric albedo of A_g = 0.093 +/- 0.029 (3 sigma upper limit of 0.175), reinforcing the unexplained trend of hot Jupiters exhibiting larger Bond albedos than geometric albedos. We also detect near-zero phase curve offsets for wavelengths above 1.5 micron, consistent with inefficient heat transport, while shorter wavelengths potentially sensitive to reflected light show eastward offsets. + oai:arXiv.org:2509.09760v2 + astro-ph.EP + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by/4.0/ - 10.3847/1538-4357/ae17ba - The Astrophysical Journal, Volume 995, pg 68, December 5 (2025) - Christopher Tiede, Daniel J. D'Orazio + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + 10.3847/1538-3881/ae0e52 + The Astronomical Journal 170 (2025) 323 + Jared Splinter, Louis-Philippe Coulombe, Robert C. Frazier, Nicolas B. Cowan, Emily Rauscher, Lisa Dang, Michael Radica, Sean Collins, Stefan Pelletier, Romain Allart, Ryan J. MacDonald, David Lafreni\`ere, Lo\"ic Albert, Bj\"orn Benneke, Ren\'e Doyon, Ray Jayawardhana, Doug Johnstone, Vigneshwaran Krishnamurthy, Caroline Piaulet-Ghorayeb, Lisa Kaltnegger, Michael R. Meyer, Jake Taylor, Jake D. Turner - SMILES Data Release II: Probing Galaxy Evolution during Cosmic Noon and Beyond with NIRSpec Medium-Resolution Spectra - https://arxiv.org/abs/2508.12599 - arXiv:2508.12599v3 Announce Type: replace -Abstract: We present the second data release of the Systematic Mid-Infrared Instrument (MIRI) Legacy Extragalactic Survey (SMILES), focusing on JWST/NIRSpec medium-resolution spectroscopy of galaxies across cosmic time. This release includes spectroscopic observations of 166 galaxies spanning $0 < z < 7.5$, sampling star-forming galaxies, quiescent systems, and active galactic nuclei (AGN), with an emphasis on galaxies at cosmic noon ($z \sim 1$-3). We describe the target selection strategy, the observational setup with the G140M/F100LP and G235M/F170LP gratings, and the data calibration process. The final data products include the reduced spectra, redshift catalog, emission-line catalogs produced with \texttt{GELATO} for emission-line galaxies and \texttt{pPXF} fits for quiescent systems, and ancillary spectral energy distribution (SED) fit results derived from multi-band photometry. The SMILES NIRSpec dataset enables investigations of obscured AGN, multi-phase outflows, ionizing properties, and the role of environment in galaxy evolution. - oai:arXiv.org:2508.12599v3 + Double Trouble: Two spectroscopically confirmed low-mass quiescent galaxies at z>5 in overdensities + https://arxiv.org/abs/2509.09761 + arXiv:2509.09761v2 Announce Type: replace +Abstract: We present the discovery of two low-mass, high-redshift, quiescent galaxies, GS-z5-Q1 and COS-z5-Q1, using JWST NIRSpec spectroscopy alongside NIRCam and MIRI photometry. Observed at a redshift of z=5.39 and z=5.11 respectively, and with stellar masses of $\rm 10^{9.6}M_\odot$ and $\rm 10^{9.5}M_\odot$, GS-z5-Q1 and COS-z5-Q1 are two of the most distant quiescent galaxies spectroscopically confirmed to-date, and are by far the least massive ($\sim10\times$ lower mass). Full spectrophotometric modelling reveals that COS-z5-Q1 appears to have quenched more than 300Myr prior to observation ($z\sim 7$) and has a formation redshift of around z$\sim$11, whilst GS-z5-Q1 formed and quenched in a single burst around 150Myr prior to observation ($z\sim6$). GS-z5-Q1 is found to lie near the centre of a known high-z overdensity in GOODS-S, as would be expected by galaxy formation models, while COS-z5-Q1 lies towards the outskirts of an overdense region. This highlights the role that environment could play in accelerating galaxy evolutionary processes and could possibly be linked to the galaxies' quiescent nature. By modelling their stellar populations, we show that these types of low-mass quiescent galaxies could potentially be descendants of the higher-z "mini-quenched" galaxies. The discovery of these two low-mass $z>5$ quiescent galaxies illuminates a previously undiscovered galaxy population and motivates dedicated follow-up surveys to investigate the overall population. + oai:arXiv.org:2509.09761v2 astro-ph.GA astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Yongda Zhu, Nina Bonaventura, Yang Sun, George H. Rieke, Stacey Alberts, Jianwei Lyu, Irene Shivaei, Jane E. Morrison, Zhiyuan Ji, Eiichi Egami, Jakob M. Helton, Marcia J. Rieke, Pierluigi Rinaldi, Fengwu Sun, Christopher N. A. Willmer + William M. Baker, Kei Ito, Francesco Valentino, Pengpei Zhu, Gianluca Scarpe, Rashmi Gottumukkala, Jens Hjorth, Laia Barrufet, Danial Langeroodi - Molecular Hydrogen in High-redshift Damped Lyman-{\alpha} Absorbers - https://arxiv.org/abs/2508.13080 - arXiv:2508.13080v2 Announce Type: replace -Abstract: Simulations predict that circumgalactic hydrogen gas surrounding massive ($M_{\rm{halo}}^{z=1}=10^{12}-10^{13}\ M_{\odot}$) galaxies at $z\sim4$ may be predominantly neutral, and could produce damped Ly$\alpha$ absorbers (DLAs) along sight-lines to background quasars \citep{Stern2021}. A circumgalactic medium (CGM) origin for DLAs naturally explains high redshift HI absorption-selected galaxy detections at physical separations much greater than the likely extents of the galaxy disks \citep{Neeleman2017, Neeleman2019}. The observed $z\sim 4$ DLA HI column densities are large and comparable to interstellar (ISM) gas columns at which substantial molecular hydrogen (H$_2$) abundances occur. We therefore investigate the possible molecular content of high-redshift CGM gas, and its potential detectability via (rest-frame) far-ultraviolet (UV) absorption line studies. For this purpose we develop an analytic sub-grid model for HI-to-H$_2$ transitions and incorporate the model with zoom-in FIRE-2 simulations of evolving high-$z$ galaxies. We include dust absorption and scattering computations for the transfer of photodissociating Lyman-Werner (LW) band radiation. We find that the typical extents of detectable H$_2$ sightlines are $\approx 0.1\, R_{\rm vir}$, independent of redshift from $z=2.5$ to 5. We argue that a CGM origin for DLAs naturally explains the low detection rates of H$_2$ in DLA observations, as the low CGM densities and relatively strong far-UV fields lead to molecular fractions much lower than observed in the ISM at comparable HI columns. - oai:arXiv.org:2508.13080v2 + Orbit-based structural decomposition and stellar population recovery for edge-on barred galaxies + https://arxiv.org/abs/2509.10832 + arXiv:2509.10832v3 Announce Type: replace +Abstract: In our previous paper, we developed an orbit-superposition method for edge-on barred galaxies and constructed a set of dynamical models based on different mock observations of three galaxies from the Auriga simulations. In this study, we adopted 12 cases with side-on bars (three simulated galaxies, each with four different projections). We decomposed these galaxies into different structures combining the kinematic and morphological properties of stellar orbits. We then compared the model-predicted components to their true counterparts in the simulations. Our models can identify (BP/X-shaped) bars, spheroidal bulges, thin discs, and spatially diffuse stellar halos. The mass fractions of bars and discs are well constrained with absolute biases of $|f_{\rm model}-f_{\rm true}|\le0.15$. We recovered the mass fractions of halos with $|f_{\rm model}-f_{\rm true}|\le0.03$. For the bulge components, 10 out of 12 cases exhibit $|f_{\rm model}-f_{\rm true}|\le0.05$, while the other two cases exhibit $|f_{\rm model}-f_{\rm true}|\le0.10$. Then, by tagging the stellar orbits with ages and metallicities, we derived the chemical properties of each structure. For the stellar ages, our models recovered the negative gradients in the bars and discs, but exhibited relatively larger uncertainties for age gradients in the bulges and halos. The mean stellar ages of all components were constrained with absolute biases $|t_{\rm model}-t_{\rm true}|\rm\lesssim1\,Gyr$. For stellar metallicities, our models reproduced the steep negative gradients of the bars and bulges, as well as all different kinds of metallicity gradients in the discs and halos. Apart from the bulge in the simulated galaxy Au-18, the mean stellar metallicities of all other components were constrained with absolute biases of $|Z_{\rm model}-Z_{\rm true}|\rm\le0.5\,Z_{\odot}$. + oai:arXiv.org:2509.10832v3 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Alon Gurman, Amiel Sternberg, Shmuel Bialy, Rachel K. Cochrane, Jonathan Stern - - - Inferring Mbh-Mbulge Evolution from the Gravitational Wave Background - https://arxiv.org/abs/2508.18126 - arXiv:2508.18126v2 Announce Type: replace -Abstract: We test the impact of an evolving supermassive black hole (SMBH) mass scaling relation (Mbh-Mbulge) on the predictions for the gravitational wave background (GWB). The observed GWB amplitude is 2-3 times higher than predicted by astrophysically informed models which suggests the need to revise the assumptions in those models. We compare a semi-analytic model's ability to reproduce the observed GWB spectrum with a static versus evolving-amplitude Mbh-Mbulge relation. We additionally consider the influence of the choice of galaxy stellar mass function on the modeled GWB spectra. Our models are able to reproduce the GWB amplitude with either a large number density of massive galaxies or a positively evolving Mbh-Mbulge amplitude (i.e., the Mbh / Mbulge ratio was higher in the past). If we assume that the Mbh-Mbulge amplitude does not evolve, our models require a galaxy stellar mass function that implies an undetected population of massive galaxies (Mstellar > 10^11 Msun at z > 1). When the Mbh-Mbulge amplitude is allowed to evolve, we can model the GWB spectrum with all fiducial values and an Mbh-Mbulge amplitude that evolves as alpha(z) = alpha_0 (1 + z)^(1.04 +/- 0.5). - oai:arXiv.org:2508.18126v2 - astro-ph.HE - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Cayenne Matt, Kayhan Gultekin, Luke Kelley, Laura Blecha, Joseph Simon, Gabriella Agazie, Akash Anumarlapudi, Anne Archibald, Zaven Arzoumanian, Jeremy Baier, Paul Baker, Bence B\'ecsy, Adam Brazier, Paul Brook, Sarah Burke-Spolaor, Rand Burnette, Robin Case, James Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James Cordes, Neil Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan DeCesar, Paul Demorest, Heling Deng, Lankeswar Dey, Timothy Dolch, Elizabeth Ferrara, William Fiore, Emmanuel Fonseca, Gabriel Freedman, Emiko Gardiner, Nate Garver-Daniels, Peter Gentile, Kyle Gersbach, Joseph Glaser, Deborah Good, C. Harris, Jeffrey Hazboun, Ross Jennings, Aaron Johnson, Megan Jones, David Kaplan, Matthew Kerr, Joey Key, Nima Laal, Michael Lam, William Lamb, Bjorn Larsen, T. Lazio, Natalia Lewandowska, Tingting Liu, Duncan Lorimer, Jing Luo, Ryan Lynch, Chung-Pei Ma, Dustin Madison, Alexander McEwen, James McKee, Maura McLaughlin, Natasha McMann, Bradley Meyers, Patrick Meyers, Chiara Mingarelli, Andrea Mitridate, Cherry Ng, David Nice, Stella Ocker, Ken Olum, Timothy Pennucci, Benetge Perera, Polina Petrov, Nihan Pol, Henri Radovan, Scott Ransom, Paul Ray, Joseph Romano, Jessie Runnoe, Alexander Saffer, Shashwat Sardesai, A. Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Brent Shapiro-Albert, Xavier Siemens, Sophia Sosa Fiscella, Ingrid Stairs, Daniel Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph Swiggum, Jacob Taylor, Stephen Taylor, Mercedes Thompson, Jacob Turner, Michele Vallisneri, Rutger van Haasteren, Sarah Vigeland, Haley Wahl, Kevin Wilson, Caitlin Witt, David Wright, Olivia Young + Yunpeng Jin, Ling Zhu, Behzad Tahmasebzadeh, Shude Mao, Glenn van de Ven, Timothy A. Davis - Disentangling Multiple Gas Kinematic Drivers in the Perseus Galaxy Cluster - https://arxiv.org/abs/2509.04421 - arXiv:2509.04421v2 Announce Type: replace -Abstract: Galaxy clusters, the Universe's largest halo structures, are filled with 10-100 million degree X-ray-emitting gas. Their evolution is shaped by energetic processes such as feedback from supermassive black holes (SMBHs) and mergers with other cosmic structures. The imprints of these processes on gas kinematic properties remain largely unknown, restricting our understanding of gas thermodynamics and energy conversion within clusters. High-resolution spectral mapping across a broad spatial-scale range provides a promising solution to this challenge, enabled by the recent launch of the XRISM X-ray Observatory. Here, we present the kinematic measurements of the X-ray-brightest Perseus cluster with XRISM, radially covering the extent of its cool core. We find direct evidence for the presence of at least two dominant drivers of gas motions operating on distinct physical scales: a small-scale driver in the inner ~60 kpc, likely associated with the SMBH feedback; and a large-scale driver in the outer core, powered by mergers. The inner driver sustains a heating rate at least an order of magnitude higher than the outer one. This finding suggests that, during the active phase, the SMBH feedback generates turbulence, which, if fully dissipated into heat, could play a significant role in offsetting radiative cooling losses in the Perseus core. Our study underscores the necessity of kinematic mapping observations of extended sources for robust conclusions on the properties of the velocity field and their role in the assembly and evolution of massive halos. It further offers a kinematic diagnostic for theoretical models of SMBH feedback. - oai:arXiv.org:2509.04421v2 - astro-ph.HE + Unveiling Central ortho-H2D+ Depletion at Sub-kau Scales in Prestellar Core G205.46-14.56M3: The First Interferometric Evidence and Implications for Deuterium Chemistry + https://arxiv.org/abs/2509.21158 + arXiv:2509.21158v2 Announce Type: replace +Abstract: Prestellar cores represent the initial conditions of star formation, but heavy molecules such as CO are strongly depleted in their cold, dense interiors, limiting the ability to probe core centers. Deuterated molecular ions therefore emerge as key tracers because deuterium fractionation is enhanced at low temperatures. We present the first direct observation of ortho-H2D+ depletion in the prestellar core G205.46-14.56M3 using ALMA 820um continuum and ortho-H2D+(110-111) data at ~300-au resolution. We confirm the previously reported two substructures, B1 and B2, and identify a central ortho-H2D+ depletion zone toward B1 with ~6$\sigma$ contrast and an inferred diameter $\lesssim$600au, together with a peak $x$(N2D+)/$x$(N2H+)=$1.03^{+0.07}_{-0.56}$. The observationally inferred profiles of $x$(ortho-H2D+) and $x$(N2D+)/$x$(N2H+) are reproduced by a deuteration-focused chemo-dynamical model; however, the central ortho-H2D+ depletion is only marginally matched within the $2\sigma$ upper limit, likely suggesting additional deuteration in the depletion zone. From these models we infer a core age of ~0.42Ma, comparable to the free-fall time, suggesting that the substructures formed via rapid, turbulence-dominated fragmentation rather than slow, quasi-static contraction. Our observations also reveal that ortho-H2D+ velocity dispersions are largely subsonic in the core and nearly thermal between B1 and B2, consistent with turbulence dissipating within a few free-fall times. These results highlight the critical role of deuterated ions for both chemical evolution and dynamics in dense cores. + oai:arXiv.org:2509.21158v2 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by/4.0/ - XRISM Collaboration, Marc Audard, Hisamitsu Awaki, Ralf Ballhausen, Aya Bamba, Ehud Behar, Rozenn Boissay-Malaquin, Laura Brenneman, Gregory V. Brown, Lia Corrales, Elisa Costantini, Renata Cumbee, Maria Diaz Trigo, Chris Done, Tadayasu Dotani, Ken Ebisawa, Megan E. Eckart, Dominique Eckert, Satoshi Eguchi, Teruaki Enoto, Yuichiro Ezoe, Adam Foster, Ryuichi Fujimoto, Yutaka Fujita, Yasushi Fukazawa, Kotaro Fukushima, Akihiro Furuzawa, Luigi Gallo, Javier A. Garcia, Liyi Gu, Matteo Guainazzi, Kouichi Hagino, Kenji Hamaguchi, Isamu Hatsukade, Katsuhiro Hayashi, Takayuki Hayashi, Natalie Hell, Edmund Hodges-Kluck, Ann Hornschemeier, Yuto Ichinohe, Daiki Ishi, Manabu Ishida, Kumi Ishikawa, Yoshitaka Ishisaki, Jelle Kaastra, Timothy Kallman, Erin Kara, Satoru Katsuda, Yoshiaki Kanemaru, Richard Kelley, Caroline Kilbourne, Shunji Kitamoto, Shogo Kobayashi, Takayoshi Kohmura, Aya Kubota, Maurice Leutenegger, Michael Loewenstein, Yoshitomo Maeda, Maxim Markevitch, Hironori Matsumoto, Kyoko Matsushita, Dan McCammon, Brian McNamara, Francois Mernier, Eric D. Miller, Jon M. Miller, Ikuyuki Mitsuishi, Misaki Mizumoto, Tsunefumi Mizuno, Koji Mori, Koji Mukai, Hiroshi Murakami, Richard Mushotzky, Hiroshi Nakajima, Kazuhiro Nakazawa, Jan-Uwe Ness, Kumiko Nobukawa, Masayoshi Nobukawa, Hirofumi Noda, Hirokazu Odaka, Shoji Ogawa, Anna Ogorzalek, Takashi Okajima, Naomi Ota, Stephane Paltani, Robert Petre, Paul Plucinsky, Frederick S. Porter, Katja Pottschmidt, Kosuke Sato, Toshiki Sato, Makoto Sawada, Hiromi Seta, Megumi Shidatsu, Aurora Simionescu, Randall Smith, Hiromasa Suzuki, Andrew Szymkowiak, Hiromitsu Takahashi, Mai Takeo, Toru Tamagawa, Keisuke Tamura, Takaaki Tanaka, Atsushi Tanimoto, Makoto Tashiro, Yukikatsu Terada, Yuichi Terashima, Yohko Tsuboi, Masahiro Tsujimoto, Hiroshi Tsunemi, Takeshi G. Tsuru, Aysegul Tumer, Hiroyuki Uchida, Nagomi Uchida, Yuusuke Uchida, Hideki Uchiyama, Yoshihiro Ueda, Shinichiro Uno, Jacco Vink, Shin Watanabe, Brian J. Williams, Satoshi Yamada, Shinya Yamada, Hiroya Yamaguchi, Kazutaka Yamaoka, Noriko Yamasaki, Makoto Yamauchi, Shigeo Yamauchi, Tahir Yaqoob, Tomokage Yoneyama, Tessei Yoshida, Mihoko Yukita, Irina Zhuravleva, Elena Bellomi, Ian Drury, Annie Heinrich, Julie Hlavacek-Larrondo, Julian Meunier, Kostas Migkas, Lior Shefler, Phillip C. Stancil, Nhut Truong, Shutaro Ueda, Benjamin Vigneron, Congyao Zhang, John ZuHone + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Sheng-Jun Lin, Sheng-Yuan Liu, Dipen Sahu, Laurent Pagani, Tien-Hao Hsieh, Naomi Hirano, Shih-Ping Lai, Tie Liu, Shih-Ying Hsu, Shanghuo Li, Kee-Tae Kim - Enhanced radio emission between a galaxy cluster pair - https://arxiv.org/abs/2509.14348 - arXiv:2509.14348v2 Announce Type: replace -Abstract: Interacting pairs of galaxy clusters offer a unique opportunity to study the properties of the gas residing in the intracluster bridge connecting them. As a consequence of the encounter, both the X-ray and radio emission from the gas are expected to be enhanced by shocks and turbulence, facilitating their detection. PSZ2 G279.79+39.09 is likely an off-axis merging system at $z = 0.29$ with its two main cluster components observed at a projected distance of $\sim$1.3 Mpc. In this paper, we investigate the presence of diffuse radio emission associated with the system. We observed this cluster pair with the MeerKAT UHF band (544-1088 MHz) for 7.5 h and with the uGMRT band 3 (300-500 MHz) for 8 h. These are the first targeted radio observations of this system. We discover diffuse synchrotron emission in the system, with indication of enhanced emission in the region bridging the cluster pair. The detection is based on the MeerKAT UHF data, while the uGMRT band 3 observation does not allow us to derive a stringent limit on the spectral index of the source. This emission is likely generated by the turbulence injected as a consequence of the cluster-cluster encounter. However, the study of its physical properties is limited by the observations currently available on the target. If the two clusters have not yet collided, this emission would resemble the radio bridges observed in A399-A401 and A1758N-S. As other systems with multiple cluster components studied in recent years, the analyzed cluster pair represents an appealing target to investigate the presence of nonthermal phenomena beyond the well-studied denser regions of the intracluster medium. While in this work we presented a new detection, our analysis underlines the need for multi-band observations to fully understand these kinds of sources. - oai:arXiv.org:2509.14348v2 - astro-ph.CO + The Formation of Electron-capture Supernovae: A Review + https://arxiv.org/abs/2509.25915 + arXiv:2509.25915v2 Announce Type: replace +Abstract: It is generally believed that the electron-capture reactions happen when the oxygen-neon (ONe) cores grow in masses close to the Chandrasekhar limit, leading to the formation of neutron stars (NSs) via electron-capture supernovae (EC-SNe). EC-SNe are predicted to be the most likely short-lived and faint optical transients, and a small ejecta mass is expected during the collapse. This kind of SNe provide an alternative channel for producing isolated NSs and NS systems, especially for the formation of X-ray binaries and double NSs. Although EC-SNe were proposed ~45 yr ago, there are still some uncertainties for the origin of EC-SNe. In this article, we review recent studies on the two classic progenitor channels of EC-SNe, i.e., the single star channel and the binary star channel. In the single star channel, EC-SNe can happen in super asymptotic giant branch stars or He stars, whereas in the binary star channel EC-SNe can occur in He stars in binaries (involving He star+MS systems and NS+He star systems) or accretion-induced collapse in white dwarf binaries (involving the single-degenerate scenario and the double-degenerate scenario). Recent progress on the two progenitor channels is discussed, including the initial parameter range for EC-SNe, the evolutionary paths to EC-SNe, related objects and some observational constraints, etc. We also make some discussions on the possible candidates for EC-SNe in this article, and the impacts of EC-SNe on some research fields, e.g., the properties of NSs, double NS population and chemical products, etc. We also discuss the differences between EC-SNe and ultra-stripped SNe in this article. Research on EC-SNe is at a pivotal stage, with key theoretical uncertainties and observational challenges requiring integrated modeling and multi-wavelength observations for robust identification. + oai:arXiv.org:2509.25915v2 astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Andrea Botteon, Turgay Caglar, Sibel D\"oner, Reinout J. van Weeren, Krista Lynne Smith + Bo Wang, Dongdong Liu, Yunlang Guo, Zhanwen Han - A Thick Volatile Atmosphere on the Ultrahot Super-Earth TOI-561 b - https://arxiv.org/abs/2509.17231 - arXiv:2509.17231v3 Announce Type: replace -Abstract: Ultrashort-period (USP) exoplanets -- with $R_p \leq 2~$R$_{\oplus}$ and periods $\leq$1 day -- are expected to be stripped of volatile atmospheres by intense host star irradiation, which is corroborated by their nominal bulk densities and previous eclipse observations consistent with bare rock surfaces. However, a few USP planets appear anomalously under-dense relative to an Earth-like composition, suggesting an exotic interior structure (e.g., core-less) or a volatile-rich secondary atmosphere increasing their apparent radius. Here we present the first dayside emission spectrum of the low-density (4.3$\pm$0.4 g~cm$^{-3}$) USP planet TOI-561 b, which orbits an iron-poor, alpha-rich, $\sim$10 Gyr old thick disk star. Our 3-5 $\mu$m JWST/NIRSpec observations demonstrate the dayside of TOI-561 b is inconsistent with a bare-rock surface at high statistical significance, suggesting instead a thick volatile envelope that is cooling the dayside to well below the $\sim$3000 K expected in the bare-rock or thin-atmosphere case. These results reject the popular hypothesis of complete atmospheric desiccation for highly irradiated exoplanets and support predictions that planetary-scale magma oceans can retain substantial reservoirs of volatiles, opening the geophysical study of ultrahot super-Earths through the lenses of their atmospheres. - oai:arXiv.org:2509.17231v3 + Polka-dotted Stars II: Starspots and obliquities of Kepler-17 and Kepler-63 + https://arxiv.org/abs/2510.07130 + arXiv:2510.07130v2 Announce Type: replace +Abstract: Starspots trace stellar magnetic activity and influence both stellar evolution and exoplanet characterization. While occultation-based spot analyses have been applied to individual systems, comparative studies remain limited. We apply the StarryStarryProcess Bayesian surface-mapping framework to archival Kepler light curves of two planet hosts, Kepler-63 and Kepler-17, extending the validation established on TOI-3884 (Paper I). Across both systems, we infer characteristic spot radii smaller than 10 degrees. The latitudinal spot distributions of these G dwarfs show active latitudes: Kepler-63 near 30 degrees and Kepler-17 near 15 degrees. Our analysis yields stellar obliquity measurements in excellent agreement with previous studies, validating our methodology and demonstrating that transit-based surface mapping can simultaneously recover planetary parameters, stellar orientations, and magnetic morphologies. Together, these results reveal a range of stellar geometries from nearly aligned (Kepler-17) to highly misaligned (Kepler-63). + oai:arXiv.org:2510.07130v2 astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + astro-ph.SR + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Johanna K. Teske, Nicole L. Wallack, Anjali A. A. Piette, Lisa Dang, Tim Lichtenberg, Mykhaylo Plotnykov, Raymond T. Pierrehumbert, Emma Postolec, Samuel Boucher, Alex McGinty, Bo Peng, Diana Valencia, Mark Hammond - - - CECILIA: Gas-Phase Physical Conditions and Multi-Element Chemistry at Cosmic Noon - https://arxiv.org/abs/2509.18257 - arXiv:2509.18257v2 Announce Type: replace -Abstract: Galaxies at Cosmic Noon (z$\sim$2-3) are characterized by rapid star formation that will lead to significant metal enrichment in the interstellar medium (ISM). While much observational evidence suggests that these galaxies are chemically distinct from those in the local Universe, directly measuring the ISM chemistry in large samples of high-z galaxies is only now possible with the observational capabilities of JWST. In this first key paper of the CECILIA program, we present the direct-method physical conditions and multi-element abundances in twenty galaxies at Cosmic Noon. Using a combination of archival Keck/MOSFIRE and new $\sim$30-hr NIRSpec spectroscopy, we measure multiple electron gas densities and the temperature structure from the O$^+$ and S$^{2+}$ ions. We find that n$_e$[O II] and n$_e$[S II] are comparable but elevated with respect to n$_e$ in local star-forming galaxies, and the simultaneous T$_e$[O II] and T$_e$[S III] generally agree with photoionization model T$_e$ scaling relations. The O abundances in the CECILIA galaxies range from 12+log(O/H)$=$7.76-8.81 (12-131% solar O/H), representing some of the highest direct-method metallicities and lowest T$_e$ (T$_e$[O II]$\approx$6500 K) measured with JWST to date. The CECILIA galaxies exhibit significantly sub-solar S/O and Ar/O a signature of predominant enrichment from core collapse supernovae. The N/O-O/H trends in the CECILIA galaxies generally agree with the abundance trends in local nebulae, but the large scatter in N/O could be sensitive to the star-formation history. The CECILIA observations demonstrate that exceptionally deep JWST spectroscopy can unveil the multi-element ISM abundance patterns in typical high-z galaxies. - oai:arXiv.org:2509.18257v2 - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Noah S. J. Rogers, Allison L. Strom, Gwen C. Rudie, Ryan F. Trainor, Caroline von Raesfeld, Menelaos Raptis, Nathalie A. Korhonen Cuestas, Tim B. Miller, Charles C. Steidel, Michael V. Maseda, Yuguang Chen, David R. Law + Sabina Sagynbayeva, Will M. Farr - Probing potential redshift-dependent systematics in the Hubble tension: Model-independent $H_0$ constraints from DESI R2 - https://arxiv.org/abs/2509.20898 - arXiv:2509.20898v2 Announce Type: replace -Abstract: We present a determination of the Hubble constant ($H_0$) using the latest observational data from multiple cosmological probes, providing an independent geometric calibration of the SN Ia distance scale. By combining baryon acoustic oscillation (BAO) measurements from the second data release of the Dark Energy Spectroscopic Instrument (DESI DR2), cosmic chronometer $H(z)$ data, and the Pantheon Plus Type Ia supernova (SN Ia) sample, we reconstruct the cosmic expansion history through Gaussian process regression without assuming a specific cosmological model. Our analysis fully incorporates the complete covariance structure and yields $H_0$ constraints at five distinct redshifts: $65.72 \pm 1.99$ (z=0.51), $67.78 \pm 1.75$ (z=0.706), $70.74 \pm 1.39$ (z=0.934), $71.04 \pm 1.93$ (z=1.321), and $68.37 \pm 3.95~\mathrm{km~s^{-1}~Mpc^{-1}}$ (z=1.484). The Bayesian combination of these measurements gives $\hat{H}_0 = 69.29 \pm 0.81~\mathrm{km~s^{-1}~Mpc^{-1}}$ with 1.2\% precision, which occupies an intermediate position between the Planck CMB result and the SH0ES local measurement. While we observe a non-monotonic pattern in $H_0$ values across redshifts, statistical tests show this apparent evolution is not significant (p = 0.208). Our approach delivers independent constraints at multiple redshifts, enabling investigation of potential redshift-dependent systematic effects in the Hubble tension. The results demonstrate that an independent geometric method yields an $H_0$ value consistent with the intermediate range of current measurements, providing a crucial cross-check of distance ladder determinations. - oai:arXiv.org:2509.20898v2 - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + XRISM/Resolve observations of Hercules X-1: vertical structure and kinematics of the disk wind + https://arxiv.org/abs/2510.07615 + arXiv:2510.07615v2 Announce Type: replace +Abstract: X-ray binary accretion disk winds can carry away a significant fraction of the matter transferred from the companion and hence strongly affect the accretion flow and the long-term evolution of the binary. However, accurate mass outflow rate measurements are challenging due to uncertainties in our understanding of the 3D wind structure. Most studies employ absorption line spectroscopy that only gives us a single sightline through the wind streamlines. Hercules X-1 is a peculiar X-ray binary which allows us to avoid this issue, as its warped, precessing accretion disk naturally presents a range of sightlines through the vertical structure of its disk wind. Here we present the first results from a large, coordinated campaign on Her X-1 led by the new XRISM observatory (with an exposure of 210 ks) and supported by XMM-Newton, NuSTAR and Chandra. We perform a time-resolved analysis and constrain the wind properties. With XRISM/Resolve, we directly detect the Her X-1 orbital motion with an amplitude of 170 km/s in the evolution of the wind velocity. After correcting for this effect, we observe an increase in wind velocity from 250 km/s to 600 km/s as the wind rises to greater heights above the disk. The wind column density decreases with increasing height, as expected, but its ionization parameter log($\xi$/erg cm s$^{-1}$) evolves only weakly from 3.65 to 3.9 as the wind expands away. Additionally, we detect a new orbital dependence of the wind properties, revealing a likely second component that appears only briefly after the eclipse by the secondary star. + oai:arXiv.org:2510.07615v2 + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Tonghua Liu, Shuo Cao, Jieci Wang + Peter Kosec, Laura Brenneman, Erin Kara, Teruaki Enoto, Takuto Narita, Koh Sakamoto, Rudiger Staubert, Francesco Barra, Andrew Fabian, Jon M. Miller, Ciro Pinto, Daniele Rogantini, Dominic Walton, Yutaro Nagai - Hunting Very High-Energy ($>$100 GeV) Emitting High-Synchrotron Peaked Blazars - https://arxiv.org/abs/2510.06017 - arXiv:2510.06017v3 Announce Type: replace -Abstract: Very-high energy (VHE; $>$100 GeV) $\gamma$-ray emission originates via some of the most extreme particle acceleration processes in the universe. Considering beamed active galactic nuclei, i.e., blazars, only a small fraction, mainly high synchrotron peak BL Lacs, have been detected in the VHE band with the ground-based Cherenkov telescopes. We utilized $\sim$16 years of Fermi-Large Area Telescope (LAT) observations in the 0.1$-$2 TeV energy range to systematically search for potential VHE emitters in a sample of high synchrotron peaked ($\nu^{\rm peak}_{\rm syn}>10^{15}$ Hz) BL Lac sources. We identified, for the first time, 92 VHE emitting blazars at $\geq 5\sigma$ confidence level. A significant VHE emission was also detected from 52 sources previously reported as VHE blazars. - Comparing with the general blazar population, these VHE emitting blazars are found to be located at low redshifts (mean $z=0.2 \pm 0.1$) and exhibit bright synchrotron emission ($\log F^{\rm peak}_{\rm syn}=-11.2 \pm 0.4$, in erg cm$^{-2}$ s$^{-1}$). We also investigated the coincidence of VHE photon arrivals with the source activity states and found that Fermi-LAT has detected VHE photons during both quiescent and elevated activity epochs. These VHE emitting blazars represent promising targets for current and next-generation ground-based Cherenkov telescopes, and provide powerful laboratories for probing particle acceleration in relativistic jets, testing multi-messenger connections, and constraining extragalactic background light models. - oai:arXiv.org:2510.06017v3 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + Chaotic Dynamics and Zero-Velocity Structures in the Pluto-Charon CR3BP + https://arxiv.org/abs/2510.13479 + arXiv:2510.13479v2 Announce Type: replace +Abstract: Pluto and Charon are a dwarf binary system with a high mass ratio $\mu$, preventing Trojan companions. This instability creates ideal intersections for low-energy pathways that spacecraft can traverse and serves as an important test case for stability at Lagrange points for high $\mu$ binaries. This study models the Pluto-Charon system in the planar Circular Restricted Three-Body Problem (CR3BP) and compares the tadpole and horseshoe orbits of a massless particle with known low-$\mu$ orbits. Moreover, it compares the trajectories for instances where the L1 neck is opened and closed, and exhibits the corresponding zero-velocity curves; RK4 integration was used to update the position and velocity of the particle. The simulations consistently showed chaotic and unpredictable trajectories, where small changes in initial parameters could completely alter the results; trajectories displayed the influence of higher values of $\mu$ on the stability of binary systems. These findings confirm that Pluto-Charon cannot host long-lived Trojan companions and instead behaves as a system of chaotic transport. Future work could extend the study to include the spatial or elliptic three-body problem, further refining the understanding of instability in high-$\mu$ binaries. + oai:arXiv.org:2510.13479v2 + astro-ph.EP + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Sushmita Agarwal, Vaidehi S. Paliya + Abdul Wahab Jbara (Independent Researcher) - Neutrinos from stars in the Milky Way - https://arxiv.org/abs/2510.07399 - arXiv:2510.07399v2 Announce Type: replace -Abstract: Neutrinos are produced during stellar evolution by means of thermal and thermonuclear processes. We model the cumulative neutrino flux expected at Earth from all stars in the Milky Way: the Galactic stellar neutrino flux (GS$\nu$F). We account for the star formation history of our Galaxy and reconstruct the spatial distribution of Galactic stars by means of a random sampling procedure based on Gaia Data Release 2. We use the stellar evolution code $\texttt{MESA}$ to compute the neutrino emission for a suite of stellar models with solar metallicity and zero-age-main-sequence mass between $0.08M_\odot$ and $100\ M_\odot$, from their pre-main sequence phase to their final fates. We then reconstruct the evolution of the neutrino spectral energy distribution for each stellar model in our suite. The GS$\nu$F lies between $\mathcal{O}(1)$ keV and $\mathcal{O}(10)$ MeV, with thermal (thermonuclear) processes responsible for shaping neutrino emission at energies smaller (larger) than $0.1$ MeV. Stars with mass larger than $\mathcal{O}(1\ M_\odot)$, located in the thin disk of the Galaxy, provide the largest contribution to the GS$\nu$F. Moreover, most of the GS$\nu$F originates from stars distant from Earth about $5-10$ kpc, implying that a large fraction of stellar neutrinos can reach us from the Galactic Center. Solar neutrinos and the diffuse supernova neutrino background have energies comparable to those of the GS$\nu$F, challenging the detection of the latter. However, directional information of solar neutrino and GS$\nu$F events, together with the annual modulation of the solar neutrino flux, could facilitate the GS$\nu$F detection; this will kick off a new era for low-energy neutrino astronomy, also providing a novel probe to discover New Physics. - oai:arXiv.org:2510.07399v2 - astro-ph.SR + The Formation Rate and Luminosity Function of Fast X-ray transients from Einstein probe + https://arxiv.org/abs/2510.13533 + arXiv:2510.13533v2 Announce Type: replace +Abstract: Following its launch on 2024 January 9, the Einstein Probe (EP) telescope has detected hundreds of fast X-ray transients (FXTs), yet their physical origins remain elusive. Understanding their luminosity function and formation rate is crucial for elucidating their nature. Recently, the EP team has provided the latest catalog of EP-detected FXTs. Based on this catalog, we present a model-independent nonparametric approach to derive the luminosity function and formation rate of FXTs. Our analysis reveals significant cosmological luminosity evolution, characterized by a scaling relationship of $(1+z)^{3.58}$. After accounting for this evolution, we establish that the local luminosity function is best represented by a broken power law, with a break luminosity of $(4.17 \pm 0.34) \times 10^{46}$ erg/s. The formation rate exhibits a broken power law as $\rho(z) \propto (1+z)^{-4.25}$ at $z \lessapprox 0.9$ and $\rho(z) \propto (1+z)^{-0.26}$ at $z \gtrapprox 0.9$, yielding a local rate of approximately $153.8_{-95.1}^{+249.4}$ Gpc$^{-3}$ yr$^{-1}$. This rate is higher than that of long gamma-ray bursts (LGRBs). Our findings indicate that a component of FXTs is associated with LGRBs. + oai:arXiv.org:2510.13533v2 astro-ph.HE - hep-ex hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Pablo Mart\'inez-Mirav\'e, Irene Tamborra - - - Photo-$z$ Estimation with Normalizing Flow - https://arxiv.org/abs/2510.10032 - arXiv:2510.10032v2 Announce Type: replace -Abstract: Accurate photometric redshift (photo-$z$) estimation is a key challenge in cosmology, as uncertainties in photo-$z$ directly limit the scientific return of large-scale structure and weak lensing studies, especially in upcoming Stage IV surveys. The problem is particularly severe for faint galaxies with sparse spectroscopic training data. In this work, we introduce nflow-$z$, a novel photo-$z$ estimation method using the powerful machine learning technique of normalizing flow. nflow-$z$ explicitly models the redshift probability distribution conditioned on the observables such as fluxes and colors. We build two nflow-$z$ implementations, dubbed cINN and cNSF, and compare their performance. We demonstrate the effectiveness of nflow-$z$ on several datasets, including a CSST mock, the COSMOS2020 catalog, and samples from DES Y1, SDSS, and DESCaLS. Our evaluation against state-of-the-art algorithms shows that nflow-$z$ performs favorably. For instance, cNSF surpasses Random Forest, Multi-Layer Perceptron, and Convolutional Neutral Network on the CSST mock test. We also achieve a ~30% improvement over official results for the faint DESCaLS sample and outperform conditional Generative Adversarial Network and Mixture Density Network methods on the DES Y1 dataset test. Furthermore, nflow-$z$ is computationally efficient, requiring only a fraction of the computing time of some of the competing algorithms. Our algorithm is particularly effective for the faint sample with sparse training data, making it highly suitable for upcoming Stage IV surveys. - oai:arXiv.org:2510.10032v2 - astro-ph.IM - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yiming Ren, Kwan Chuen Chan, Le Zhang, Yin Li, Haolin Zhang, Ruiyu Song, Yan Gong, Xian-Min Meng, Xingchen Zhou - - - Exploring the connection between compact object mergers and fast X-ray transients: The cases of LXT 240402A and EP250207b - https://arxiv.org/abs/2510.13015 - arXiv:2510.13015v5 Announce Type: replace -Abstract: The connection between compact object mergers and some extragalactic fast X-ray transients (FXRTs) has long been hypothesized, but never ultimately established. In this work, we investigate two FXRTs, the LEIA X-ray Transient LXT 240402A and the Einstein Probe EP250207b, whose precise positions lie close to nearby ($z\!\lesssim\!0.1$) quiescent galaxies with negligible probability of chance coincidence, identifying them as particularly promising cases of merger-driven explosions in the local Universe. We used Chandra to derive accurate localizations for both events and secure otherwise ambiguous associations with their optical counterparts. Deep optical and near-infrared observations with VLT, GTC, and LBT were performed to characterize the surrounding environment and search for kilonova emission, the hallmark of neutron star mergers. Complementary early-time X-ray monitoring with Swift and Einstein Probe was used to constrain the non-thermal afterglow. We find that both FXRTs remain compatible with a compact binary merger progenitor, which produced low-mass ejecta and kilonova emission subdominant to the afterglow. However, alternative explanations such as a distant ($z\!\gtrsim\!1$) core-collapse supernova cannot be conclusively ruled out. - oai:arXiv.org:2510.13015v5 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1051/0004-6361/202557612 - R. L. Becerra, Yu-Han Yang, Eleonora Troja, Massine El Kabir, Simone Dichiara, Niccol\`o Passaleva, Brendan O'Connor, Roberto Ricci, Chris Fryer, Lei Hu, Qinyu Wu, Muskan Yadav, Alan M. Watson, Anastasia Tsvetkova, Camila Angulo-Valdez, Mar\'ia D. Caballero-Garc\'ia, Alberto J. Castro-Tirado, C. C. Cheung, Dmitry Frederiks, Maria Gritsevich, J. E. Grove, M. Kerr, William H. Lee, Alexandra L. Lysenko, Margarita Pereyra Talamantes, Anna Ridnaia, Rub\'en S\'anchez-Ram\'irez, Hui Sun, Dmitry Svinkin, Mikhail Ulanov, R. Woolf, Bing Zhang + 10.3847/2041-8213/ae2745 + Yizhou Guo, Houdun Zeng, Junjie Wei, Hao Zhou, Zhiping Jin, Xuefeng Wu, Daming Wei - Relativistic reflection within an extended hot plasma geometry - https://arxiv.org/abs/2510.13337 - arXiv:2510.13337v2 Announce Type: replace -Abstract: The reflection of X-rays at the inner accretion disk around black holes imprints relativistically broadened features in the observed spectrum. Aside from the black hole properties and the ionization and density of the accretion disk, these features also depend on the location and geometry of the primary source of X-rays, often referred to as the corona. We present a fast general relativistic model for spectral fitting of a radially extended, ring-like corona above the accretion disk. A common approach used to explain observed X-ray reflection spectra is the lamp post geometry, which assumes a point-like source on the rotational axis of the black hole. While it is typically able to explain the observations, this geometric model does not allow for any constraint to be placed on the radial size of the corona. We therefore extended the publicly available relativistic reflection model relxill by implementing a radially extended, ring-like primary source. With the new RELXILL model allowing us to vary the position of the primary source in two dimensions, we present simulated line profiles and spectra and discuss the implications of carrying out a data fitting, in comparison to the lamp post model. We applied this extended RELXILL model to XMM-Newton and NuSTAR data of the radio-quiet Seyfert-2 active galactic nucleus (AGN) ESO 033-G002. The new model describes the data well and we are able to constrain the distance of the source to the black hole to be less than three gravitational radii, while the angular position of the source is poorly constrained. We show that a compact, radially extended corona close to the innermost stable circular orbit is able to explain the observed relativistic reflection as well as the lamp post corona does. This model has been made freely available to the community. - oai:arXiv.org:2510.13337v2 + Bell Instability and Cosmic-Ray Acceleration in AGN Ultrafast Outflow Shocks + https://arxiv.org/abs/2510.13946 + arXiv:2510.13946v2 Announce Type: replace +Abstract: We investigate magnetic-field amplification driven by the nonresonant hybrid (NRH or Bell) instability and its impact on cosmic-ray (CR) acceleration at reverse shocks of ultrafast outflows (UFOs) from active galactic nuclei (AGN). Previous kinetic studies by particle-in-cell simulations have demonstrated that when maximum CR energy is near the injection scale, NRH instability efficiently amplifies magnetic field up to the saturation level. However, the efficiency of NRH instability goes down as maximum energy increase since CR current is carried by escaping CRs near the maximum energy. We employ a one-dimensional MHD--CR framework solving telegraph-type diffusion--convection equations to trace the coupled evolution of CRs, magnetic fields, and shock dynamics under realistic parameters. We find a distinct transition with magnetic field strength: for weak background fields ($B_{0}\!\lesssim\!10^{-4}\,\mathrm{G}$), NRH instability efficiently amplifies upstream turbulence, driving a self-regulated state where $E_{\max}$ becomes independent of initial strength of magnetic turbulence. In contrast, for stronger background fields ($B_{0}\!\gtrsim\!10^{-3}\,\mathrm{G}$), the escaping CR current is too weak to drive NRH instability, and magnetic turbulence further decays through parametric instabilities, potentially reducing the acceleration efficiency. We give the physical interpretation for the transition and discuss conditions for PeV--EeV acceleration at UFO reverse shocks. + oai:arXiv.org:2510.13946v2 astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + physics.plasm-ph + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by/4.0/ - 10.1051/0004-6361/202556012 - A&A, 704, A129 (2025) - Alexey D. Nekrasov, Thomas Dauser, Javier A. Garcia, Dominic J. Walton, Christian M. Fromm, Andrew J. Young, Fergus J. E. Baker, Amy M. Joyce, Ole Koenig, Stefan Licklederer, Julia Haefner, Joern Wilms + http://creativecommons.org/publicdomain/zero/1.0/ + Rei Nishiura, Tsuyoshi Inoue - The Hidden Story of Chemical Evolution in Local Star-Forming Nuclear Rings - https://arxiv.org/abs/2510.14757 - arXiv:2510.14757v2 Announce Type: replace -Abstract: A VLT/MUSE population synthesis study of metallicities in the nuclear star-forming rings of four disk galaxies (NGC 613, NGC 1097, NGC 3351, NGC 7552) is presented. Disentangling the spectral contributions of young and old stellar populations, we find a large spread of ages and metallicities of the old stars in the nuclear rings. This indicates a persistent infall of metal-poor gas and ongoing episodic star formation over many gigayears. The young stars have metallicities a factor two to three higher than solar in all galaxies except NGC 3351, where the range is from half to twice solar. Previously reported detections of extremely metal poor regions at young stellar age on the rings of these four galaxies are a methodological artifact of the average over all stars, young and old. In addition, it is important to include contributions of very young stars ($<6$ Myr) in this environment. For each of the four galaxies, the extinction maps generated through our population synthesis analysis provide support for the infall scenario. They reveal dust lanes along the leading edges of the stellar bars, indicating the flow of interstellar material towards the circumnuclear zone. Prominent stellar clusters show little extinction, most likely because of the onset of stellar winds. Inside and on the nuclear rings, regions that are largely free of extinction are detected. - oai:arXiv.org:2510.14757v2 + A sensitivity analysis of interstellar ice chemistry in astrochemical models + https://arxiv.org/abs/2511.01042 + arXiv:2511.01042v2 Announce Type: replace +Abstract: Astrochemical models are essential to bridge the gap between the timescales of reactions, experiments, and observations. Ice chemistry in these models experiences a large computational complexity as a result of the many parameters required for the modeling of chemistry occurring on these ices, such as binding energies and reaction energy barriers. Many of these parameters are poorly constrained, and accurately determining all would be too costly. We aim to find out which parameters describing ice chemistry have a large effect on the calculated abundances of ices for different prestellar objects. Using Monte Carlo sampled binding energies, diffusion barriers, desorption and diffusion prefactors, and reaction energy barriers, we determined the sensitivity of the abundances of the main ice species calculated with UCLCHEM, an astrochemical modeling code, on each of these parameters. We do this for a large grid of physical conditions across temperature, density, cosmic ray ionization rate and UV field strength. We find that, regardless of the physical conditions, the main sensitivities of abundances of the main ice species are the diffusion barriers of small and relatively mobile reactive species such as H, N, O, HCO, and CH$_3$. Thus, these parameters should be determined more accurately to increase the accuracy of models, paving the way to a better understanding of observations of ices. In many cases, accurate reaction energy barriers are not essential due to the treatment of competition between reactions and diffusion. + oai:arXiv.org:2511.01042v2 astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Eva Sextl, Rolf-Peter Kudritzki + Tobias M. Dijkhuis, Thanja Lamberts, Serena Viti, Herma M. Cuppen - SPHEREx: Aromatics, Aliphatics and PAH Size across the Iris Nebula - https://arxiv.org/abs/2510.20919 - arXiv:2510.20919v3 Announce Type: replace -Abstract: Observations by the SpectroPhotometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx) are combined with Spitzer spectral map data to study the aromatic, aliphatic, and PAH size evolution across the northwest photo-dissociation region (PDR) of the Iris Nebula (NGC7023). The 3.3-3.4 $\mu$m complex (I$_{3.3}$) and 11.2 $\mu$m (I$_{11.2}$) PAH band strength are determined through direct integration. In addition, the former is decomposed into a 3.3 (I'$_{3.3}$) and 3.4 $\mu$m (I'$_{3.4}$) sub-feature by fitting SPHEREx bandpass-integrated photometry using a modeled, highly sampled, multi-component spectrum. I$_{3.3}$, I$_{11.2}$, I'$_{3.3}$, and I'$_{3.4}$ all peak at the PDR. The NASA Ames PAH IR Spectroscopic Database is used to obtain the average number of carbon atoms ($\overline{\rm N_{C}}$) and small PAH fraction ($f_{\rm small}$) by fitting the isolated PAH component of the Spitzer segment; $70\lesssim\overline{N_{C}}\lesssim76$ and $0.24\lesssim\text{f}_{\rm small}\lesssim0.36$. I'$_{3.4}$/I'$_{3.4}$, I$_{11.2}$/I$_{3.3}$, $\overline{\rm N_{C}}$, and $f_{\rm small}$ all show a demarcation that matches the large-scale morphology of the region. For I'$_{3.3}$ and I'$_{3.4}$ this is reflected by two distinct trends when plotted against each other, one associated with the dense, the other with the diffuse medium; $[N_{\rm H,ali}/N_{\rm H,aro}]_{\rm dense}$ = 0.42$\pm$0.01 and $[N_{\rm H,ali}/N_{\rm H,aro}]_{\rm diffuse}$ = 0.10$\pm$0.01. $\overline{\rm N_{C}}$ and $f_{\rm small}$ are tentatively correlated with I$_{11.2}$/I$_{3.3}$ (R=0.54$\pm$0.05 and -0.45$\pm$0.05, respectively). A wider variety of large(r) extended interstellar medium objects is required to tighten the correlations, turn them into quantitative calibrators for PAH size, and pin down the discrepancy of correlations with I'$_{3.3}$ involved. - oai:arXiv.org:2510.20919v3 + The Local Group L-band Survey: Probing Cold Atomic Gas in IC10 with Neutral Hydrogen Absorption + https://arxiv.org/abs/2511.10602 + arXiv:2511.10602v2 Announce Type: replace +Abstract: We present the first localized detections of the cold neutral medium (CNM) in IC10, offering a rare view of dense atomic gas in a low-metallicity (0.27 solar metallicity) dwarf galaxy. As a low-metallicity starburst, IC10's interstellar medium conditions could reflect small-scale physical conditions that mirror those of early galaxies, providing a unique window into the heating and cooling processes that shaped the interstellar medium in early-Universe environments. Leveraging the high angular (<5'' ~ 15pc) and spectral (0.4 km/s) resolution of the Local Group L-band Survey, we searched for HI absorption against nine continuum radio sources and detected absorption along three sightlines corresponding to internal radio emission sources within IC10. Using Gaussian decomposition and radiative transfer, we characterize the CNM, deriving spin temperatures of ~30-55 K, column densities of (0.6-3.0)x 1$0^{21}$ cm$^{-2}$, cold HI fractions of ~ 21-37%, and line widths of ~ 5.6-13.6 km/s. For each individual detection of HI absorption, we find corresponding molecular emission from 12CO (J=1-0), HCO+ (J=1-0), and HCN (J=1-0) at similar velocities and with comparable linewidths, indicating a well-mixed cold atomic and molecular medium. In IC10, the CNM shows a clear kinematic connection to the high-density ISM, implying a stronger dynamical coupling with molecular gas than in the Milky Way, in line with expectations for low-metallicity environments. At the ~ 15 pc scales probed by slightly extended HII regions in IC10, unresolved CNM clouds likely contribute to line blending, so the observed broad HI linewidths may partly reflect spatial and kinematic averaging. + oai:arXiv.org:2511.10602v2 astro-ph.GA - astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Christiaan Boersma, Alexandros Maragkoudakis, Louis J. Allamandola, Jesse D. Bregman, Pasquale Temi, Vincent J. Esposito, Ryan C. Fortenberry + Ioana A. Stelea, Snezana Stanimirovic, Nickolas M. Pingel, Hongxing Chen, Eric W. Koch, Adam K. Leroy, Erik Rosolowsky, Chang-Goo Kim, Alberto D. Bolatto, Julianne J. Dalcanton, Michael P. Busch, Harrisen Corbould, J. R. Dawson, Cosima Eibensteiner, Amanda Kepley, Melanie Krips, Claire E. Murray, Julia Roman-Duval, Daniel R. Rybarczyk, Evan D. Skillman, Elizabeth Tarantino, Vicente Villanueva, Thomas G. Williams - Sco X-1 as a continuous gravitational waves source: modelling the secular evolution using MESA - https://arxiv.org/abs/2510.21529 - arXiv:2510.21529v2 Announce Type: replace -Abstract: We study the prospects for detecting continuous gravitational waves (GWs) from Sco X-1 and evaluate the most likely waveform and progenitor parameters. We model the spin of the neutron star by the accretion torque and the gravitational-wave torque, considering two mechanisms for generating the non-axisymmetry responsible for the latter: magnetic mountains and crustal breakage deformation. Both torques are intertwined with the binary evolution, which we trace from the formation of the NS in a binary system with a main-sequence companion. We do this with MESA, starting from a set of initial binary configurations. At current sensitivity, a magnetic ellipticity of $\varepsilon\gtrsim 10^{-6}$ is necessary for detection. The highest frequency at which we have detectable signals increases with the accretion efficiency $\eta$, and it can be as high as 360Hz. At 3G (Cosmic Explorer/Einstein telescope) sensitivity, less deformed Sco X-1 NSs, with ellipticities as small as $6\cdot 10^{-9}$, are detectable, but the waveform highly depends on the binary system: the highest frequency of detectable signals spans the very broad range 600-1700Hz, strongly depending on $\eta$ and mass of the progenitor donor star $M^d$. If $\eta\leq$30%, the crust does not break. For $\eta\in$[40%,60%] only progenitors with $M^d\geq[1.1,1.5]M_{\odot}$ present crustal breakage, while if $\eta\geq$70% all crusts break. In some systems, the crust breaks during their Sco X-1 phase. If Sco X-1 were one of those systems, it would be emitting a very loud GW signal sweeping from O(1000)Hz down to torque-balance frequencies in $\approx 150000[\varepsilon /10^{-5}]^{-2/5}$ years. We estimate the current detection probability for this signal to be under 1%; this probability increases substantially - to around 41% - with 3G detectors. - oai:arXiv.org:2510.21529v2 - astro-ph.HE - gr-qc - Wed, 10 Dec 2025 00:00:00 -0500 + The ensemble broad-frequency power spectrum of Stripe-82 quasars from multiple surveys + https://arxiv.org/abs/2511.16615 + arXiv:2511.16615v2 Announce Type: replace +Abstract: Variability is a striking features of quasars, observed at all timescales wavelengths. Studying its properties and the correlations with the physical parameters (e.g. black hole mass and accretion rate) provides significant insights into accretion physics. However, the detailed picture and the exact interplay between different emitting regions are not yet clear. We combine data from Sloan Digital Sky Survey (SDSS), the Panoramic Survey Telescope and Rapid Response System 1 (Pan-STARRS1, PS1), the Zwicky Transient Facility (ZTF), and the Gaia space telescope to constrain the power spectrum of quasars in the Stripe-82 region over a broad frequency range, 10^{-1} to 10^{-3} day^{-1}(rest frame). Light curves are matched and cross-calibrated to reach \sim 20 years in the r-band for 4037 quasars. We split the sample into bins of the same black hole mass, accretion rate, and redshift, and measure the ensemble power spectral density (PSD) in each bin. The power spectra of SDSS, ZTF, and Gaia are measured independently. We do not measure it on PS1 data due to more erratic cadence, but we discuss the use of interpolation techniques, eventually allowing us to use the data together. We find significant evidence that the long-term UV/optical variability of quasars is stationary, as the ensemble PSD estimates from SDSS, Gaia and ZTF are consistent within the errors despite coming from different surveys and years. The PSD shape is consistent with a bending power law with spectral indices of -2.7 and -1 at high and low frequencies. A fit with the PSD associated with a damped random walk is significantly worse. The PSD amplitude below the break does not depend on black hole mass, but there is some evidence for anti-correlation with the accretion rate. The bending frequency, instead, scales with the black hole mass as $\nu_b$ \propto M_{\mathrm{BH}}^{-0.6\pm0.1} and does not depend on the accretion rate. + oai:arXiv.org:2511.16615v2 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Gianluca Pagliaro, Maria Alessandra Papa, Jing Ming, Devina Misra + 10.1051/0004-6361/202557044 + Vincenzo Petrecca, Iossif E. Papadakis, Maurizio Paolillo, Demetra De Cicco, Franz E. Bauer, Maria Isabel Carnerero, Claudia Maria Raiteri, Marta Fatovic - Is The Trace Anomaly at its Minimum Value at Neutron Star Centers? - https://arxiv.org/abs/2511.03714 - arXiv:2511.03714v2 Announce Type: replace -Abstract: While the equation of state (EOS) $P(\varepsilon)$ of neutron star (NS) matter has been extensively studied, the EOS-parameter $\phi = P/\varepsilon$ or equivalently the dimensionless trace anomaly $\Delta = 1/3 - \phi$, which quantifies the balance between pressure $P$ and energy density $\varepsilon$, remains far less explored, especially in NS cores. Its bounds and density profile carry crucial information about the nature of superdense matter. Physically, the EOS-parameter $\phi$ represents the mean stiffness of matter accumulated from the stellar surface up to a given density. Based on the intrinsic structure of the Tolman--Oppenheimer--Volkoff equations, we show that $\phi$ decreases monotonically outward from the NS center, independent of any specific input NS EOS model. Furthermore, observational evidence of a peak in the speed-of-sound squared (SSS) density-profile near the center effectively rules out a valley and a subsequent peak in the radial profile of $\phi$ at similar densities, reinforcing its monotonic decrease. These model-independent relations impose strong constraints on the near-center behavior of the EOS-parameter $\phi$, particularly demonstrating that the mean stiffness (or equivalently $\Delta$) reaches a local maximum (minimum) at the center. - oai:arXiv.org:2511.03714v2 + Entity -- Hardware-agnostic Particle-in-Cell Code for Plasma Astrophysics. I: Curvilinear Special Relativistic Module + https://arxiv.org/abs/2511.17710 + arXiv:2511.17710v2 Announce Type: replace +Abstract: Entity is a new-generation, fully open-source particle-in-cell (PIC) code developed to overcome key limitations in astrophysical plasma modeling, particularly the extreme separation of scales and the performance challenges associated with evolving, GPU-centric computing infrastructures. It achieves hardware-agnostic performance portability across various GPU and CPU architectures using the Kokkos library. Crucially, Entity maintains a high standard for usability, clarity, and customizability, offering a robust and easy-to-use framework for developing new algorithms and grid geometries, which allows extensive control without requiring edits to the core source code. This paper details the core general-coordinate special-relativistic module. Entity is the first PIC code designed to solve the Vlasov-Maxwell system in general coordinates, enabling a coordinate-agnostic framework that provides the foundational structure for straightforward extension to arbitrary coordinate geometries. The core methodology achieves numerical stability by solving particle equations of motion in the global orthonormal Cartesian basis, despite using generalized coordinates like Cartesian, axisymmetric spherical, and quasi-spherical grids. Charge conservation is ensured via a specialized current deposition technique using conformal currents. The code exhibits robust scalability and performance portability on major GPU platforms (AMD MI250X, NVIDIA A100, and Intel Max Series), with the 3D particle pusher and the current deposition operating efficiently at about 2 nanoseconds per particle per timestep. Functionality is validated through a comprehensive suite of standard Cartesian plasma tests and the accurate modeling of relativistic magnetospheres in curvilinear axisymmetric geometries. + oai:arXiv.org:2511.17710v2 astro-ph.HE - hep-ph - hep-th - nucl-ex - nucl-th - Wed, 10 Dec 2025 00:00:00 -0500 + physics.plasm-ph + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/publicdomain/zero/1.0/ - Bao-Jun Cai, Bao-An Li, Yu-Gang Ma + http://creativecommons.org/licenses/by/4.0/ + Hayk Hakobyan, Ludwig M. B\"oss, Yangyang Cai, Alexander Chernoglazov, Alisa Galishnikova, Evgeny A. Gorbunov, Jens F. Mahlmann, Alexander Philippov, Siddhant Solanki, Arno Vanthieghem, Muni Zhou - Accretion Geometry of the New Galactic Black Hole Candidate AT2019wey in the Hard State - https://arxiv.org/abs/2511.06393 - arXiv:2511.06393v3 Announce Type: replace -Abstract: We perform broadband spectral and timing studies of the Galactic low-mass black hole candidate AT2019wey using quasi-simultaneous NICER, Swift, and NuSTAR observations obtained in 2022. The long-term MAXI light curve, along with the hardness-intensity diagram (HID), indicates that the source remained in the hard state and did not switch to the soft state. Spectral modeling using two different model combinations reveals that the broadband spectrum is best described by two distinct Comptonizing regions, associated reflection components, and thermal emission from the disk. The harder Comptonizing region dominates ($\gtrsim80\%$) the total flux and is primarily responsible for the observed reflection features from the distant part of the disk. We find that the accretion disk is truncated at a radius of $\sim16-56~r_{\rm{g}}$, while the luminosity is $\sim1.9\%$ of the Eddington limit, assuming a black hole mass of $10 ~ M_\odot$ and distance of 8 kpc. Our spectral results also show consistency in the estimated inner disk radius obtained through two independent methods: modeling the disk continuum and the reflection spectrum. The variability studies imply the presence of intrinsic disk variability, likely originating from an instability in the disk. We also detect hard time lags at low frequencies, possibly arising from the inward propagation of mass accretion rate fluctuations from the outer to the inner regions of the accretion disk. Moreover, an observed deviation of the lag-energy spectrum from the log-linear trend at $\lesssim 0.7$ keV is most likely attributed to thermal reverberation, arising from the reprocessing of hard coronal photons in the accretion disk. - oai:arXiv.org:2511.06393v3 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + ACES: The Magnetic Field in Large Filaments in the Galactic Center + https://arxiv.org/abs/2511.18029 + arXiv:2511.18029v3 Announce Type: replace +Abstract: The Galactic Center (GC) is an extreme region of the Milky Way that is host to a complex set of thermal and non-thermal structures. In particular, the GC contains high-density gas and dust that is collectively referred to as the Central Molecular Zone (CMZ). In this work, we study a subset of HNCO filaments identified in band 3 ALMA observations of the GC obtained by the ALMA CMZ Exploration Survey (ACES) that are comparable to high density filaments identified in the Galactic Disk. We compare the orientation of the magnetic field derived from 214 um SOFIA and 850 um JCMT observations with the filament orientation to determine which mechanisms dominate the formation of these filaments. We observe a large range of magnetic orientations in our observed filaments indicating the complex environments the filaments are located in. We also compare the observational results to synthetic data sets created using an MHD model of the GC. Our analysis reveals that the dominant mechanisms local to the HNCO filaments vary throughout the GC with some filaments being dominated by supersonic turbulence and others by subsonic turbulence. The comparison to synthetic observations indicates that the observed filaments are in magnetically dominated environments that could be supporting these filaments against collapse. Our results on the CMZ filaments are also compared to results obtained on similar filaments located in the Galactic Disk, and we find that the filaments studied here are possible CMZ analogs to the dense filamentary "bones" observed previously in the Galactic Disk. + oai:arXiv.org:2511.18029v3 + astro-ph.GA + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Pragati Sahu, Swadesh Chand, Gulab C. Dewangan, Andrzej A. Zdziarski, Vivek K. Agrawal, Parijat Thakur + http://creativecommons.org/licenses/by/4.0/ + Dylan M. Par\'e, Zi-Xuan Feng, Yue Hu, Maya A. Petkova, Jack Sullivan, Robin G. Tress, Cara Battersby, Janik Karoly, Alex Lazarian, Dani Lipman, Xing Pan, Marco Donati, Mattia C. Sormani, John Bally, Ashley T. Barnes, Natalie O. Butterfield, Laura Colzi, Christoph Federrath, Pablo Garcia, Adam Ginsburg, Savannah R. Gramze, Anika Schmiedeke, Christian Henkel, Jonathan D. Henshaw, Paul T. Ho, Pei-Ying Hsieh, Izaskun Jimenez-Serra, Ralf S. Klessen, J. M. Diederik Kruijssen, Steven N. Longmore, Xing Lu, Elisabeth A. C. Mills, \'Alvaro S\'anchez-Monge, Daniel L. Walker, Jennifer Wallace, Qizhou Zhang - The Transition from Giant Planets to Brown Dwarfs beyond 1 au from the Stellar Metallicity Distribution - https://arxiv.org/abs/2511.11818 - arXiv:2511.11818v2 Announce Type: replace -Abstract: Giant planets and brown dwarfs are thought to form via a combination of pathways, including bottom-up mechanisms in which gas is accreted onto a solid core and top-down mechanisms in which gas collapses directly into a gravitationally-bound object. One can distinguish the prevalence of these mechanisms using host star metallicities. Bottom-up formation thrives in metal-rich environments, whereas top-down formation is weakly dependent on ambient metal content. Using a hierarchical Bayesian model and the results of the California Legacy Survey (CLS), a low-bias and homogeneously analyzed radial velocity survey, we find evidence for a transition in the stellar metallicity distribution at a companion mass of $\gamma = 27_{-8}^{+12} \, M_{\rm Jup}$ for companions with orbital separations between $1-50$ au. Companions below and above this threshold tend to orbit stars with higher ($\rm{[Fe/H]} = 0.17 \pm 0.12$ dex) and lower ($\rm{[Fe/H]} = -0.03 \pm 0.10$ dex) metallicities, respectively. Previous studies of relatively close-in companions reported evidence of a lower transition mass of $\leq 10 \, {\rm M_{\rm Jup}}$. When applied to the CLS sample, our model predicts the probability of a transition in the stellar metallicity distribution at or below $10 \, { M_{\rm Jup}}$ to be $< 1 \%$. We compare our results to estimates of $\gamma$ gleaned from other observational metrics and discuss implications for planet formation theory. - oai:arXiv.org:2511.11818v2 - astro-ph.EP + Predictions of gravity mode pulsations of collisional blue straggler stars in globular clusters + https://arxiv.org/abs/2511.23189 + arXiv:2511.23189v2 Announce Type: replace +Abstract: Blue straggler stars (BSSs) are exotic objects, which, being the results of processes such as mass transfer, mergers, or collisions, are considered key objects in the study of their host clusters' dynamics. While many studies on astrometric, spectroscopic, and photometric properties of BSSs in clusters have been conducted, there are few works in the literature regarding their pulsations and internal structure, which can indeed retain traces of their origin. In this work we computed and analysed a grid of collisional BSSs at low metallicity ($Z = 0.01\; Z_\odot$), finding that collision products present a peculiar chemical stratification that leads to periodicities in the period-spacing pattern of high-order gravity modes. These seismic fingerprints provide a unique opportunity to constrain the formation pathways of BSSs in globular clusters. + oai:arXiv.org:2511.23189v2 astro-ph.SR - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Steven Giacalone, Andrew W. Howard, Gregory J. Gilbert, Judah Van Zandt, Erik A. Petigura, Luke B. Handley + 10.1051/0004-6361/202557567 + Lorenzo Briganti, Walter Eduard van Rossem, Andrea Miglio, Angela Bragaglia, Massimiliano Matteuzzi - Shaping the Mantle: The Role of Superheated Core After Giant Impacts - https://arxiv.org/abs/2511.13436 - arXiv:2511.13436v5 Announce Type: replace -Abstract: The Moon-forming giant impact significantly influenced the initial thermal state of Earth's mantle by generating a global magma ocean, marking the onset of mantle evolution. Recent Smoothed Particle Hydrodynamics (SPH) simulations indicate that such a collision would produce a superheated core, whose cooling would strongly influence subsequent mantle dynamics. Here, we present systematic SPH simulations of diverse giant-impact scenarios and show that the superheated core formed after the impact can trigger secondary mantle melting, thereby governing the final state of the magma ocean. To further quantify this effect, we employ a parameterized mantle-melting model to evaluate the influence of secondary melting on the lower mantle. Our results suggest three possible outcomes: complete mantle melting, the formation of a basal melt layer, or the initiation of an early superplume. Combined with recent two-phase magma-ocean solidification models, we infer that all three scenarios would result in basal melt layers of varying thickness, partially retaining the thermal energy of the superheated core. In the canonical Moon-forming scenario, the superheated core would rapidly transfer heat to Earth's lower mantle, causing secondary mantle melting within approximately 277-5983 years and generating either a basal melt layer or a fully molten mantle. Both outcomes would effectively erase primordial heterogeneities in the lower mantle and impose distinct pathways for its subsequent thermal evolution. - oai:arXiv.org:2511.13436v5 - astro-ph.EP - Wed, 10 Dec 2025 00:00:00 -0500 + Progress towards a microchannel plate detector with AlGaN photocathode and cross-strip anode for ultraviolet astronomy + https://arxiv.org/abs/2512.04669 + arXiv:2512.04669v2 Announce Type: replace +Abstract: Microchannel plates (MCPs) were the driving detector technology for ultraviolet (UV) astronomy over many years, and still today MCP-based detectors are the baseline for several planned UV instruments. The development of advanced MCP detectors is ongoing and pursues the major goals of maximizing sensitivity, resolution, and lifetime, while at the same time decreasing weight, volume, and power consumption. + Development efforts for an MCP-based detector system for the UV are running at IAAT at the University of T\"ubingen. In this publication, we present our latest results towards coating aluminum gallium nitride (AlGaN) photocathodes directly on MCPs, to improve quantum detection efficiency in the far- and extreme-UV. Furthermore, we report on the implementation of a non-iterative centroiding algorithm for our coplanar cross-strip anode directly in an FPGA. + oai:arXiv.org:2512.04669v2 + astro-ph.IM + physics.ins-det + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by/4.0/ - You Zhou + http://creativecommons.org/licenses/by-nc-sa/4.0/ + 10.1117/1.JATIS.11.4.042230 + Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 11, Issue 4, 042230 (October 2025) + S. Diebold, J. Barnstedt, L. Conti, H. R. Elsener, L. Hanke, M. H\"oltzli, C. Kalkuhl, D. Rau, D. Schaadt, T. Schanz, B. Stelzer, K. Werner - A model-independent assessment of the late-time dark energy density evolution - https://arxiv.org/abs/2511.13666 - arXiv:2511.13666v2 Announce Type: replace -Abstract: Combined measurements of Baryon Acoustic Oscillations (BAO) from the Dark Energy Spectroscopic Survey (DESI), the Cosmic Microwave Background (CMB) and Type Ia Supernovae (SN Ia), have recently challenged the $\Lambda$-Cold Dark Matter ($\Lambda$CDM) paradigm, indicating potential evidence for a dynamical dark energy component. These results are usually obtained in the context of the dark energy equation-of-state (EoS) parameterizations, generally implying in phantom-crossing at intermediate redshifts. However, a general mapping between these parameterizations that yields approximately the same background observables clouds the inference of the true nature of dark energy in the context of these parametric methods. In this work, we propose a model-independent reconstruction of the dark energy density, which is more directly constrained than its EoS, based on the Gaussian Process (GP) regression method with the use of DESI DR2 BAO data and the Pantheon+, Union3 and DESY5 SN Ia samples. In addition, we perform a statistical comparison between the energy densities of $\Lambda$, a non-phantom thawing quintessence-type dark energy, and the Chevallier-Polarski-Linder parameterization with the reconstructed function. We find that all models agree with the GP reconstruction at 95\% C.L., with the largest discrepancy coming from $\Lambda$CDM with DESY5 at low redshifts. Even in this case, our findings suggest that it may be premature to claim statistically significant evidence for evolving or phantom dark energy with current DESI and SN Ia measurements. - oai:arXiv.org:2511.13666v2 + What Galaxy Clusters Have to Say About Dynamical Dark Energy and $H_0$ + https://arxiv.org/abs/2512.06701 + arXiv:2512.06701v2 Announce Type: replace +Abstract: We show that, in flat $\Lambda$CDM, low-redshift structure probes -- cluster abundances, 3$\times$2-point analyses, and full-shape clustering -- are mutually consistent, jointly delivering precise constraints on $\sigma_8$ and $\Omega_{\rm m}$ that agree with geometrical datasets (CMB+BAO+SN). In $w_0w_a$CDM, adding clusters to the geometry dataset reduces the evidence for evolving dark energy while relaxing the $H_0$ tension, suggesting a $\Lambda$CDM evolution of the late-time Universe and a sound horizon that differs from its standard value. + oai:arXiv.org:2512.06701v2 astro-ph.CO - gr-qc - hep-ph - hep-th - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Rayff de Souza, Agripino Sousa-Neto, Javier E. Gonz\'alez, Jailson Alcaniz - - - From Flash to Crater: Morphological and Spectral Analysis of the Brightest Lunar Impact on 11 September 2013 using LRO Data - https://arxiv.org/abs/2511.14442 - arXiv:2511.14442v2 Announce Type: replace -Abstract: We present a comprehensive morphological and spectrophotometric analysis of the lunar impact that occurred on September 11, 2013, based on pre- and post-event observations by the Lunar Reconnaissance Orbiter (LRO). The crater formed exhibits a rim-to-rim diameter of $35 \pm 0.7$ m, a depth of $4.9 \pm 0.4$ m, and an ejecta blanket extending over 2 km with an area of approximately $7 \times 10^{5}\,$m$^{2}$. The ejecta shows a pronounced asymmetry and, assuming uniform distribution, an average thickness limit of $\sim 2$ mm. Spectral analysis using WAC images reveals a consistent reddening of the central ejecta region, with an average 16.54 % increase in spectral slope between 321 nm and 643 nm, marking the first reported detection of color changes resulting from a lunar impact. We evaluated several scaling laws and found that the Gault et al. (1974) formulation most accurately reproduces the observed crater size. Furthermore, luminous efficiency values below $\eta = 2 \times 10^{-3}$ and higher projectile densities are most consistent with the morphology of the ejecta. The impact direction inferred from this pattern is not compatible with the radiant of the September $\varepsilon$-Perseids stream. Moreover, an independent probability analysis yields a greater than 96 % likelihood that the event was caused by a sporadic meteoroid. Our results also demonstrate the potential of WAC imagery for the automated detection of new lunar craters, which can improve statistical estimates of the current impact flux. This methodology offers a powerful complement to high-resolution imaging, with important implications for both lunar safety and planetary defense. - oai:arXiv.org:2511.14442v2 - astro-ph.EP - astro-ph.IM - Wed, 10 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - 10.1093/mnras/staf2068 - J. L. Rizos, L. M. Lara, J. L. Ortiz, J. M. Madiedo + http://creativecommons.org/licenses/by/4.0/ + Andr\'es N. Salcedo, Eduardo Rozo, Hao-Yi Wu, Shulei Cao, Enrique Paillas, Hanyu Zhang, Eli S. Rykoff - The Albedo Problem and Cloud Cover on Hot Jupiters - https://arxiv.org/abs/2511.18497 - arXiv:2511.18497v2 Announce Type: replace -Abstract: Observations of transiting hot Jupiters have revealed a mismatch between the values of the Bond versus geometric albedos. In the planetary science literature, the ratio of these quantities is known as the phase integral. It has been extensively measured for the Solar System planets and shown to generally be non-unity in value. We use existing Cassini data of Jupiter to derive bandpass-integrated geometric albedos and phase integrals in the CHEOPS, TESS and Ariel bandpasses, demonstrating that these quantities vary markedly across these different wavelength ranges. By performing a population study of geometric albedos and phase integrals, we demonstrate that atmospheres with partial cloud cover may be identified using measurements of the phase integral if its measured uncertainty is $\sim 0.1$, which corresponds to an uncertainty of $\sim 3\%$ on the optical/visible secondary eclipse depth. The upcoming Ariel space mission will conduct an unprecedented statistical survey of cloud cover on hot Jupiters via the simultaneous measurement of $\sim 100$ infrared phase curves and optical secondary eclipses. Whenever available, the shape of optical phase curves of reflected light will directly constrain the phase integral, spherical albedo, degree of cloud cover and scattering asymmetry factor. - oai:arXiv.org:2511.18497v2 - astro-ph.EP - physics.ao-ph - Wed, 10 Dec 2025 00:00:00 -0500 + Tracing Nitrogen Enrichment across Cosmic Time with JWST + https://arxiv.org/abs/2512.07955 + arXiv:2512.07955v2 Announce Type: replace +Abstract: We present a comprehensive analysis of the nitrogen-to-oxygen (N/O) abundance ratio in star-forming galaxies at redshift z~1-6, with a median redshift of z=2.7, using deep JWST/NIRSpec spectroscopy. Leveraging detections of faint auroral emission lines in 76 galaxies at z>1 from both the MARTA survey and a large compilation of high-redshift literature objects, we derive direct electron temperature-based abundances for nitrogen and oxygen using rest-frame optical lines. We establish the first high-redshift calibrations of strong-line N/O diagnostics based on direct abundance measurements, finding no significant evolution for either N2O2 = [NII]6585/[OII]3727,3729 and N2S2 = [NII]6585/[SII]6717,6731 diagnostics compared to local realisations. We then investigate the N/O-O/H relation across cosmic time using both direct abundances and strong-line based measurements (additional 430 galaxies). We find evidence for mild but systematic nitrogen enhancement at high redshift: galaxies at z>1 exhibit N/O ratios elevated by ~0.18 dex (median offset) at fixed O/H compared to the local relation, with a more pronounced enhancement at low metallicity (12+log(O/H) < 8.1) where the offset reaches up to ~0.3-0.4 dex. We consider several scenarios to explain the observed trends, including bursty star formation, differential metal loading, and inflows of pristine gas. Our results provide the most extensive confirmation of elevated N/O ratios at high-redshift to date based on rest-optical diagnostics and within a self-consistent frame. + oai:arXiv.org:2512.07955v2 + astro-ph.GA + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Kevin Heng, Billy Edwards, Nicolas B. Cowan + E. Cataldi, F. Belfiore, M. Curti, B. Moreschini, A. Marconi, R. Maiolino, A. Feltre, M. Ginolfi, F. Mannucci, G. Cresci, X. Ji, A. Amiri, M. Arnaboldi, E. Bertola, C. Bracci, M. Ceci, A. Chakraborty, F. Cullen, Q. D'Amato, C. Kobayashi, I. Lamperti, C. Marconcini, M. Scialpi, L. Ulivi, M. V. Zanchettin - Dynamical Dark Energy in light of DESI BAO and Full-Shape Data - https://arxiv.org/abs/2512.07104 - arXiv:2512.07104v2 Announce Type: replace -Abstract: Recently, the DESI BAO data has reported a preference of dynamical dark energy (DDE) over the \LambdaCDM cosmology. Apart from the BAO data, the DDE model should be also sensitive to low-redshift measurements of the matter power spectrum data. In this study, we address this point by combining the DESI Y1 data about the matter power spectrum, extracted from the DESI Full-Shape data, with the DESI DR2 BAO data among other probes. After building the DESI Y1 likelihood, we carry out a Markov Chain Monte Carlo analysis, showing that the constraints on $w_0$ and $w_a$ with DESI Y1 data included are improved over those without it for three different datasets widely considered, especially in the case of the DESY5 sample. - oai:arXiv.org:2512.07104v2 + The frame-dragging vector potential on galaxy scales from DM-only Newtonian $N$-body simulations + https://arxiv.org/abs/2512.08703 + arXiv:2512.08703v2 Announce Type: replace +Abstract: Effects of General Relativity are usually neglected in the non-linear evolution of structures, where Newtonian $N$-body simulations are traditionally employed. In the post-Friedmann expansion framework, a weak-field relativistic approximation purpose-built for cosmology, a frame-dragging gravito-magnetic vector potential arises at leading order, sourced by momentum currents, contributing to the metric even if the dynamics of matter fields at this order is Newtonian, and can thus be extracted from $N$-body simulations. Using the Delaunay Tessellation Field Estimator code on the IllustrisTNG simulations, here we extend previous work in order to compute the power spectrum of this vector potential down to galactic scales. The magnitude of the vector potential is two orders of magnitude larger than predicted by perturbation theory, and is a $1\% \sim 0.1\%$ effect compared to the non-linear Newtonian scalar gravitational potential. In the red-shift range considered here, the gravito-magnetic effect remains subdominant, without showing any enhancement during a particular phase in the evolution of structures, aside from the continuous growth of non-linearity at low redshift. Although this seems to suggest that, within the $\Lambda$CDM model, no significant gravito-magnetic effects contribute to the non-linear evolution of cosmic structures, i.e. to the dynamics of massive particles, possible observational consequences, e.g. in lensing, deserve further exploration. + oai:arXiv.org:2512.08703v2 astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.GA + gr-qc + Thu, 11 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Quan Zhou, Sibo Zheng + William Beordo, Marco Bruni, Cristian Barrera-Hinojosa, Mariateresa Crosta - Multi-Wavelength Afterglows as Diagnostic Probes of Dense Circumburst Medium in GRBs - https://arxiv.org/abs/2512.07719 - arXiv:2512.07719v2 Announce Type: replace -Abstract: Gamma-ray bursts (GRBs) are generally believed to occur in environments where the surrounding medium is either a uniform interstellar medium (ISM) or, in some cases, a dense stellar wind from a massive progenitor. Recently, GRB 191019A has been proposed to originate within the accretion disk of an active galactic nucleus (AGN), suggesting that some GRBs may occur in extremely dense environments, although this interpretation remains under debate. This scenario has drawn considerable attention, as AGN disks are promising sites that can host progenitors of both long and short GRBs, and whose dense, gas-rich environment could significantly influence jet propagation and afterglow emission. Yet, our theoretical understanding of the resulting afterglow signatures in such environments is limited, and further systematic exploration is required. In this study, we investigate how multi-wavelength afterglow light curves can be utilized as diagnostic tools to probe the nature of the circumburst environment. Our results show that in dense environments, GRB afterglows exhibit distinct frequency-dependent behaviors. For jets with large opening angles, the X-ray light curve displays a shallow decay or bump due to a transition from synchrotron to SSC dominance, while the optical and high-energy (GeV) light curves follow typical power-law decays. On the other hand, for small opening angles, the light curves exhibit wavelength-dependent jet breaks: the GeV and optical bands break simultaneously, while the X-ray break is delayed as the SSC component gradually compensates for the fading synchrotron component. These signatures provide potential diagnostics of GRBs occurring in dense media such as AGN disks. - oai:arXiv.org:2512.07719v2 - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 - replace + Ekpyrosis in Quantum Gravitational Anisotropic Bouncing Models + https://arxiv.org/abs/2412.12274 + arXiv:2412.12274v2 Announce Type: replace-cross +Abstract: We explore the isotropization of a model anisotropic universe in the bouncing models using the ekpyrotic potential without assuming initial conditions corresponding to an ekpyrotic phase. In particular, we explore the way the use of ekpyrotic potentials may dynamically help isotropization for the considered initial conditions corresponding to the macroscopic classical contracting universe with potentially large anisotropies. As an example of a concrete nonsingular bouncing mechanism, we consider the effective description of loop quantum cosmology for Bianchi-I and Bianchi-IX spacetimes for ekpyrotic and ekpyrotic-like potentials. Considering two different values of potential parameters and initial conditions corresponding to a classical macroscopic universe, we show that for both of these spacetimes, the cosmological singularity is resolved via multiple short-duration nonsingular bounces caused by quantum gravitational effects. We perform a large number of numerical simulations for a wide range of initial conditions which do not favor ekpyrosis initially. Even with such unfavorable initial conditions, we show that the relative strength of the anisotropies at the end of the bounce regime is noticeably reduced in more than 90% of the simulations. This provides a strong evidence for the isotropization ability of the ekpyrotic potentials. We find that isotropization can occur over cycles of rapid nonsingular bounces in the Planck regime via enhancement of the contribution of the (isotropic) energy density relative to the anisotropies at the bounces. Achieving isotropization is found to be easier in Bianchi-I spacetimes when compared to Bianchi-IX spacetimes. Our results demonstrate that, even with initial conditions which are not most favorable for the existence of ekpyrosis, an effective isotropization can occur in nonsingular anisotropic models with ekpyrotic and ekpyrotic-like potentials. + oai:arXiv.org:2412.12274v2 + gr-qc + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 + replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xiao-Hong Zhao + 10.1103/p4vk-2v43 + Phys. Rev. D 112, 126006 (2025) + Rachel Brown, A. Meenakshi McNamara, Sahil Saini, Parampreet Singh - DESI Strong Lens Foundry V: A Sample of HST-Observed Strong Lenses Modeled with GIGA-Lens - https://arxiv.org/abs/2512.07823 - arXiv:2512.07823v2 Announce Type: replace -Abstract: We present six galaxy-scale strong lenses with HST imaging modeled using GIGA-Lens. This is Paper V of the DESI Strong Lens Foundry series. These systems were discovered in the DESI Legacy Imaging Surveys using ML/AI methods and confirmed with DESI, Keck/NIRES, and VLT/MUSE spectroscopy. They span $z_d = 0.39 - 1.1$ and $z_s = 1.4 - 3.3$. This is the first HST strong lens sample modeled with full forward modeling -- all lens and source parameters sampled simultaneously in a single inference -- with explicit convergence validation using both $\widehat{R}$ and effective sample size (ESS) for each system. All inferred parameters satisfy $\widehat{R} < 1.1$ and ${\rm ESS} \gtrsim 10,000$, demonstrating that GIGA-Lens achieves statistically robust inference even for some of the most complex galaxy-scale lenses known. These results pave the way for scaling to much larger, high-resolution strong lens samples from HST, Euclid, JWST, and Roman. Convergence-validated modeling will be critical for key science goals, including constraining the mass-density profile of galaxies, detecting low-mass dark matter (sub)halos, and delivering precise and accurate cosmological constraints. - oai:arXiv.org:2512.07823v2 + Gravitational Wave Mountains: current-carrying domain walls + https://arxiv.org/abs/2501.01542 + arXiv:2501.01542v3 Announce Type: replace-cross +Abstract: Domain wall (DW) networks may have formed in the early universe following the spontaneous breaking of a discrete symmetry. Notably, several particle physics models predict the existence of current-carrying DWs, which can capture and store particles as zero modes on it. In this study, we demonstrate that gravitational waves (GWs) generated by current-carrying DWs with fermionic zeromodes exhibit a novel feature: an additional peak in the GW spectrum resembling mountains, arising from metastable topological remnants, which we term ``spherons.'' This distinct signature could be detectable in upcoming GW observatories such as LISA and ET. The results suggest that DW networks in beyond Standard Model scenarios could emit GW signals that are significantly stronger and with greater detectability than previously expected. + oai:arXiv.org:2501.01542v3 + hep-ph astro-ph.CO - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Xiaosheng Huang, David Alvarez-Garcia, Monica Ubeda, Vikram Bhamre, Sean Xu, S. Baltasar, N. Ratier-Werbin, F. Urcelay, S. Agarwal, A. Cikota, Y. Hsu, E. Lin, D. J. Schlegel, E. Silver, C. J. Storfer, M. Tamargo-Arizmendi - - - Neural Surrogate HMC: On Using Neural Likelihoods for Hamiltonian Monte Carlo in Simulation-Based Inference - https://arxiv.org/abs/2407.20432 - arXiv:2407.20432v2 Announce Type: replace-cross -Abstract: Bayesian inference methods such as Markov Chain Monte Carlo (MCMC) typically require repeated computations of the likelihood function, but in some scenarios this is infeasible and alternative methods are needed. Simulation-based inference (SBI) methods address this problem by using machine learning to amortize computations. In this work, we highlight a particular synergy between the SBI method of neural likelihood estimation and the classic MCMC method of Hamiltonian Monte Carlo. We show that approximating the likelihood function with a neural network model can provide three distinct advantages: (1) amortizing the computations for MCMC; (2) providing gradients for Hamiltonian Monte Carlo, and (3) smoothing over noisy simulations resulting from numerical instabilities. We provide practical guidelines for defining a prior, sampling a training set, and evaluating convergence. The method is demonstrated in an application modeling the heliospheric transport of galactic cosmic rays, where it enables efficient inference of latent parameters in the Parker equation. - oai:arXiv.org:2407.20432v2 - cs.LG - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + hep-th + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Linnea M Wolniewicz, Peter Sadowski, Claudio Corti + 10.1103/24w5-rflt + Phys.Rev.D 112 (2025) 11, 115019 + Anish Ghoshal, Yu Hamada - Superheavy Supersymmetric Dark Matter for the origin of KM3NeT Ultra-High Energy signal - https://arxiv.org/abs/2503.18737 - arXiv:2503.18737v2 Announce Type: replace-cross -Abstract: We propose an explanation for the recently reported ultra-high-energy neutrino signal at KM3NeT, which shows no clear association with known astrophysical sources. While decaying dark matter in the Galactic Center is a natural candidate, the observed arrival direction strongly suggests an extragalactic origin. We introduce a multicomponent dark matter scenario in which the components are part of a supermultiplet, with supersymmetry ensuring a nearly degenerate mass spectrum among the fields with different spins. In this setup, a cosmologically long-lived fermionic state decays into a slightly lighter bosonic dark matter state, producing a boosted neutrino spectrum with energy $E_\nu \sim 100$ PeV, determined by the mass difference. The heavy-to-light decay occurs at a cosmological redshift of $z \sim \text{a few}$ or higher, leading to an isotropic directional distribution of the signal. - oai:arXiv.org:2503.18737v2 + Scalar Rayleigh Dark Matter: current bounds and future prospects + https://arxiv.org/abs/2501.09073 + arXiv:2501.09073v2 Announce Type: replace-cross +Abstract: Dark Matter can interact with electroweak gauge bosons via higher-dimensional operators, in spite of being neutral under gauge interactions, much like neutral atoms interact with photons through Rayleigh scattering. This study explores effective interactions between a real scalar Dark Matter particle, singlet under the SM gauge group, and electroweak gauge bosons. We present a comprehensive analysis of current constraints and projected sensitivities from both lepton and hadron colliders as well as direct and indirect detection experiments in testing Rayleigh Dark Matter interactions. We find that, thanks to the complementarity between collider experiments and cosmological probes, thermally produced Rayleigh Dark Matter at the hundreds of GeV scale can be thoroughly tested with the next generation of experiments. For lighter candidates, upcoming forecasts will explore uncharted parameter space, significantly surpassing the thermal Dark Matter benchmark. + oai:arXiv.org:2501.09073v2 hep-ph - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.CO + hep-ex + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by/4.0/ - 10.1103/7jgm-f852 - Yongsoo Jho, Seong Chan Park, Chang Sub Shin + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Daniele Barducci, Dario Buttazzo, Alessandro Dondarini, Roberto Franceschini, Giulio Marino, Federico Mescia, Paolo Panci - Power-Law Bounces in $f(R)$ Gravity: Analysis of the Ekpyrosis and Accelerating Regimes - https://arxiv.org/abs/2507.00242 - arXiv:2507.00242v3 Announce Type: replace-cross -Abstract: We investigate the dynamics of the Friedmann-Lema\^itre-Robertson-Walker spacetime within the framework of $f(R)$ gravity using a compact, model-independent dynamical systems approach. By assuming a power-law scale factor, we explore ekpyrotic and accelerating solutions to address the big bang singularity. Our analysis demonstrates that a cosmological bounce, characterized by a transition from contraction to expansion, possibly avoids the singularity without directly using the Raychaudhuri equation, unlike previous approaches using specific $f(R) \simeq R^n$ forms. We identify a key fixed point in the phase space corresponding to the bounce, supported by perturbation analysis and qualitative description of trajectories in the phase space. The results suggest that $f(R)$ gravity provides a robust framework for non-singular cosmologies. - oai:arXiv.org:2507.00242v3 + Initial acquisition requirements for optical cavities in the space gravitational wave antennae DECIGO and B-DECIGO + https://arxiv.org/abs/2503.12960 + arXiv:2503.12960v2 Announce Type: replace-cross +Abstract: DECIGO (DECi-hertz Interferometer Gravitational Wave Observatory) is a space-based gravitational wave antenna concept targeting the 0.1-10 Hz band. It consists of three spacecraft arranged in an equilateral triangle with 1,000 km sides, forming Fabry-P\'erot cavities between them. A precursor mission, B-DECIGO, is also planned, featuring a smaller 100 km triangle. Operating these cavities requires ultra-precise formation flying, where inter-mirror distance and alignment must be precisely controlled. Achieving this necessitates a sequential improvement in precision using various sensors and actuators, from the deployment of the spacecraft to laser link acquisition and ultimately to the control of the Fabry-P\'erot cavities to maintain resonance. In this paper, we derive the precision requirements at each stage and discuss the feasibility of achieving them. We show that the relative speed between cavity mirrors must be controlled at the sub-micrometer-per-second level and that relative alignment must be maintained at the sub-microradian level to obtain control signals from the Fabry-P\'erot cavities of DECIGO and B-DECIGO. + oai:arXiv.org:2503.12960v2 gr-qc - astro-ph.CO - hep-th - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + physics.ins-det + physics.optics + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - 10.1103/rrnm-z3qy - Phys. Rev. D 112, 104059 (2025) - Saurya Das, Peter Dunsby, S. Shajidul Haque, Seturumane Tema + 10.1088/1361-6382/ae1b61 + Classical and Quantum Gravity 42, 225027 (2025) + Yuta Michimura, Koji Nagano, Kentaro Komori, Kiwamu Izumi, Takahiro Ito, Satoshi Ikari, Tomotada Akutsu, Masaki Ando, Isao Kawano, Mitsuru Musha, Shuichi Sato - Comparing a Compact-Binary Mass-Shell Model with Select Observed Gravitational Waves - https://arxiv.org/abs/2508.07499 - arXiv:2508.07499v2 Announce Type: replace-cross -Abstract: In a recent work, coalescing compact binaries (CCBs) were modeled as a rotating and contracting compact mass shell, providing an alternative effective representation to the state-of-the-art effective-one-body approach. Using a variational methodology, the Laplace-Beltrami formulation of the Ricci tensor was applied to a Kerr metric Ansatz, and the corresponding energy density $T_{00}$ of the CCB mass shell was obtained via the Einstein field equations. At the time of coalescence $t_C$, the resulting surface energy depends on the reduced mass $\mu$, the symmetric mass ratio $\alpha$, and the normalized orbital spin velocity of the CCB. In this work, we evaluate the radiated energy predicted by this variational approach for 45 select gravitational wave (GW) events from the O1--O4 runs, and compare these values with those inferred from observational catalogs, either directly or via the total-minus-remnant mass difference. For 38 of the 45 events analyzed, the predicted radiated energies agree with observationally inferred values within the reported uncertainties, with 1:1 ratios spanning from $0.828$ to $0.997$ (mean $0.942$, median $0.955$). Three events exhibit ratios in the range $0.721\sim0.779$, one event yields a ratio of $0.466$, and for the remaining events the radiated energy is either unconstrained or inaccessible due to undocumented total-minus-remnant mass differences. These results indicate that the analytical approximation captures, for the most part, the leading-order energy scaling of compact binary mergers, while also suggesting clear avenues for further systematic improvement, including incorporating post-Newtonian corrections due to e.g. a non-zero eccentricity or combined tidal deformability. - oai:arXiv.org:2508.07499v2 + Results from Hubble parameter data: oscillating dark energy? + https://arxiv.org/abs/2505.00058 + arXiv:2505.00058v2 Announce Type: replace-cross +Abstract: Using a model-independent analysis method which bases on the Lagrange mean value theorem for obtaining the derivative of the Hubble function, we analyze $H(z)$ parameter data with some restrictive conditions. We find that: (a) the Universe may experience an accelerated expansion with a confidence level greater than 5 $\sigma$ at redshift $z_{101}\in (0, 0.36)$ and greater than 1.9 $\sigma$ at redshifts $z_{3835}\in (1.3, 1.53)$ and $z_{3836}\in (1.43, 1.53)$, where $z_j<z_{ij}<z_i$ and $i$ marks the $i$-th Hubble parameter data we consider; (b) the Universe may experience a decelerated expansion with a confidence level greater than 1.5 $\sigma$ at redshift $z_{2012}\in (0.40, 0.52)$; (c) $w_{\rm{x}}\leq w_{\rm{t}}<-1$ with confidence level great than 1.6 $\sigma$ at redshift $z_{3836}\in (1.43, 1.53)$. These results indicate that the evolution of dark energy may be oscillatory. + oai:arXiv.org:2505.00058v2 gr-qc - astro-ph.HE - hep-th - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by/4.0/ - Noah M. MacKay + http://creativecommons.org/licenses/by-nc-sa/4.0/ + 10.1088/1674-4527/ae1720 + Res.Astron.Astrophys.26 (2026) 1, 015003 + Rong-Jia Yang - Exact Taub-NUT-like Black Holes in Einstein-bumblebee gravity: their thermodynamics and thermodynamic topology - https://arxiv.org/abs/2509.17407 - arXiv:2509.17407v3 Announce Type: replace-cross -Abstract: We re-derive an exact analytic three-parameter expressions for the non-rotating metric, describing a Taub-NUT-like black hole (BH), and its associated bumblebee field that are solutions to the Einstein-bumblebee gravity. We construct a consistence thermodynamics for the Taub-NUT-like BH and determine its thermodynamic topological class. The Lorentz symmetry breaking affects the mass and temperature of the BH but does not affect its thermodynamic topological classification. - oai:arXiv.org:2509.17407v3 + Neutrino Decoherence via Modified Dispersion + https://arxiv.org/abs/2505.16699 + arXiv:2505.16699v2 Announce Type: replace-cross +Abstract: We study in detail the effect of quantum decoherence in neutrino oscillations. We adopt a phenomenological approach that allows us to parametrize the energy dependence of the decoherence effects resulting from the modification of the neutrino dispersion relation. Using the open quantum system framework we derive decoherence parameters, which are usually connected to quantum gravitational effects. Furthermore, we study the sensitivity of decoherence on high-energy astrophysical neutrinos among all possible initial source compositions. We find that variation in the flux composition at neutrino telescopes can be a good probe to test such effects. Additionally, we show that a simple extension with heavy sterile neutrino decoherence produces verifiable signatures. + oai:arXiv.org:2505.16699v2 + hep-ph + astro-ph.HE gr-qc - astro-ph.GA - math-ph - math.MP - Wed, 10 Dec 2025 00:00:00 -0500 + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1016/j.nuclphysb.2025.117257 - Mustapha Azreg-A\"inou, Yassine Sekhmani + 10.1088/1475-7516/2025/12/015 + JCAP 12 (2025) 015 + Bikash Kumar Acharya, Indra Kumar Banerjee, Ujjal Kumar Dey - Semianalytic calculation of the gravitational wave spectrum induced by curvature perturbations - https://arxiv.org/abs/2509.18694 - arXiv:2509.18694v2 Announce Type: replace-cross -Abstract: The stochastic gravitational wave (GW) background is secondarily and inevitably induced by the primordial curvature perturbations beyond the first order of the cosmological perturbation theory. We analytically calculate the integration kernel of the power spectrum of the induced GWs, which is the universal part independent of the spectrum of the primordial curvature perturbations, in the radiation-dominated era and in the matter-dominated era. We derive fully analytic expressions of the GW spectrum when possible. As a minor update, we study the case of the top-hat function as the spectrum of the curvature perturbations. We also discuss generalization in the presence of multiple cosmological eras with different equations of state. - oai:arXiv.org:2509.18694v2 - gr-qc + Dark Matter Freeze-In and Small-Scale Observables: Novel Mass Bounds and Viable Particle Candidates + https://arxiv.org/abs/2506.13864 + arXiv:2506.13864v3 Announce Type: replace-cross +Abstract: The suppression of cosmological structure at small scales is a key signature of dark matter (DM) produced via freeze-in in the low-mass regime. We present a comprehensive analysis of its impact, incorporating recent constraints from Milky Way satellite counts, strong gravitational lensing with JWST data, and the Lyman-$\alpha$ forest. We adopt a general strategy to translate existing warm dark matter (WDM) bounds into lower mass limits for a broad class of DM candidates characterized by quasi-thermal phase space distributions. The benefits of this approach include computational efficiency and the ability to explore a wide range of models. We derive model-independent bounds for DM produced via two-body decays, scatterings, and three-body decays, and apply the framework to concrete scenarios such as the Higgs portal, sterile neutrinos, axion-like particles, and the dark photon portal. Results from specific models confirm the validity of the model-independent analysis. + oai:arXiv.org:2506.13864v3 + hep-ph astro-ph.CO + Thu, 11 Dec 2025 00:00:00 -0500 + replace-cross + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Francesco D'Eramo, Alessandro Lenoci, Ariane Dekker + + + Low-Energy Supernova Constraints on Lepton Flavor Violating Axions + https://arxiv.org/abs/2506.16922 + arXiv:2506.16922v2 Announce Type: replace-cross +Abstract: The extreme conditions within the supernova core, a high-temperature and high-density environment, create an ideal laboratory for the search for new physics beyond the Standard Model. Of particular interest are low-energy supernovae, characterized by their low explosion energies, which place strong constraints on the new-physics energy transfer from the core to the mantle. We compute low-energy supernova constraints on lepton-flavor-violating axions and axion-like particles that couple to both electrons and muons. For axion mass above the muon mass, the electron-muon coalescence and the axion decay are dominant production and reabsorption processes, respectively. We find that the low-energy supernovae provide the most stringent constraints on the axions in the mass range of $\sim (110,550)$ MeV, probing the coupling constant down to $g_{ae\mu} \simeq {\cal O}(10^{-11})$. + oai:arXiv.org:2506.16922v2 hep-ph - hep-th - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.CO + astro-ph.HE + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Takahiro Terada + Zi-Miao Huang, Zuowei Liu - Einstein gravity extended by a scale covariant scalar field with Bekenstein term and dynamical mass generation - https://arxiv.org/abs/2510.17704 - arXiv:2510.17704v2 Announce Type: replace-cross -Abstract: Under carefully chosen assumptions a single general relativistic scalar field is able to induce MOND-like dynamics in the weak field approximation of the Einstein frame (gauge) and to modify the light cone structure accordingly. This is shown by a Lagrangian model formulated in the framework of integrable Weyl geometry. It contains a Bekenstein-type (``aquadratic'') term and a second order term generating additional mass energy for the scalar field. Both are switched on only if the gradient of the scalar field is spacelike and below a MOND-typical threshold, like in the superfluid model of Berezhiani/Khoury. The mass term induces non-negligible energy and pressures of the scalar field and leads to gravitational light deflection compatible with MOND-ian free fall trajectories. In the weak field (Newton-Milgrom) approximation the Bekenstein term implies a deep MOND equation for the scalar field. In this model the external field effect of the MOND approach has to be reconsidered. - oai:arXiv.org:2510.17704v2 - gr-qc - astro-ph.GA - Wed, 10 Dec 2025 00:00:00 -0500 + Low-Energy Calibration of SuperCDMS HVeV Cryogenic Silicon Calorimeters Using Compton Steps + https://arxiv.org/abs/2508.02402 + arXiv:2508.02402v2 Announce Type: replace-cross +Abstract: Cryogenic calorimeters for low-mass dark matter searches have achieved sub-eV energy resolutions, driving advances in both low-energy calibration techniques and our understanding of detector physics. The energy deposition spectrum of gamma rays scattering off target materials exhibits step-like features, known as Compton steps, near the binding energies of atomic electrons. We demonstrate a successful use of Compton steps for sub-keV calibration of cryogenic silicon calorimeters, utilizing four SuperCDMS High-Voltage eV-resolution (HVeV) detectors operated with 0 V bias across the crystal. This new calibration at 0 V is compared with the established high-voltage calibration using optical photons. The comparison indicates that the detector response at 0 V is about 30% weaker than expected, highlighting challenges in detector response modeling for low-mass dark matter searches. + oai:arXiv.org:2508.02402v2 + physics.ins-det + astro-ph.IM + hep-ex + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by/4.0/ - Erhard Scholz + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + 10.1103/jj7w-gkgg + Phys.Rev.D 112 (2025) 092014 + SuperCDMS Collaboration, M. F. Albakry, I. Alkhatib, D. Alonso-Gon\'zalez, D. W. P. Amaral, J. Anczarski, T. Aralis, T. Aramaki, I. Ataee Langroudy, C. Bathurst, R. Bhattacharyya, A. J. Biffl, P. L. Brink, M. Buchanan, R. Bunker, B. Cabrera, R. Calkins, R. A. Cameron, C. Cartaro, D. G. Cerde\~no, Y. -Y. Chang, M. Chaudhuri, J. -H. Chen, R. Chen, N. Chott, J. Cooley, H. Coombes, P. Cushman, R. Cyna, S. Das, S. Dharani, M. L. di Vacri, M. D. Diamond, M. Elwan, S. Fallows, E. Fascione, E. Figueroa-Feliciano, S. L. Franzen, A. Gevorgian, M. Ghaith, G. Godden, J. Golatkar, S. R. Golwala, R. Gualtieri, J. Hall, S. A. S. Harms, C. Hays, B. A. Hines, Z. Hong, L. Hsu, M. E. Huber, V. Iyer, V. K. S. Kashyap, S. T. D. Keller, M. H. Kelsey, K. T. Kennard, Z. Kromer, A. Kubik, N. A. Kurinsky, M. Lee, J. Leyva, B. Lichtenberg, J. Liu, Y. Liu, E. Lopez Asamar, P. Lukens, R. L\'opez No\'e, D. B. MacFarlane, R. Mahapatra, J. S. Mammo, N. Mast, A. J. Mayer, P. C. McNamara, H. Meyer zu Theenhausen, \'E. Michaud, E. Michielin, K. Mickelson, N. Mirabolfathi, M. Mirzakhani, B. Mohanty, D. Mondal, D. Monteiro, J. Nelson, H. Neog, V. Novati, J. L. Orrell, M. D. Osborne, S. M. Oser, L. Pandey, S. Pandey, R. Partridge, P. K. Patel, D. S. Pedreros, W. Peng, W. L. Perry, R. Podviianiuk, M. Potts, S. S. Poudel, A. Pradeep, M. Pyle, W. Rau, E. Reid, R. Ren, T. Reynolds, M. Rios, A. Roberts, A. E. Robinson, L. Rosado Del Rio, J. L. Ryan, T. Saab, D. Sadek, B. Sadoulet, S. P. Sahoo, I. Saikia, S. Salehi, J. Sander, B. Sandoval, A. Sattari, B. Schmidt, R. W. Schnee, B. Serfass, A. E. Sharbaugh, R. S. Shenoy, A. Simchony, P. Sinervo, Z. J. Smith, R. Soni, K. Stifter, J. Street, M. Stukel, H. Sun, E. Tanner, N. Tenpas, D. Toback, A. N. Villano, J. Viol, B. von Krosigk, Y. Wang, O. Wen, Z. Williams, M. J. Wilson, J. Winchell, S. Yellin, B. A. Young, B. Zatschler, S. Zatschler, A. Zaytsev, E. Zhang, L. Zheng, A. Zuniga, M. J. Zurowski - Holographic Constraints on the String Landscape - https://arxiv.org/abs/2511.15784 - arXiv:2511.15784v2 Announce Type: replace-cross -Abstract: We show that holography imposes strong and general constraints on scalar field potentials in the string landscape, determined by the asymptotic structure of the underlying spacetime. Applying these holographic consistency conditions, we identify broad classes of scalar potentials that are incompatible with a well-defined dual description. These include potentials with extended plateaus, excessively steep or shallow asymptotics, certain zero crossings, and specific alignments of stable AdS minima in moduli space. In particular, making the standard assumption that the CFT dual to a stable AdS vacuum must be realized as a worldvolume theory of a brane in string theory, we show that the brane selects an infinite-distance limit in moduli space where parametric scale separation is forbidden. Furthermore, the steepness and positivity of the potential are restricted in that infinite distance direction. We also find that requiring the validity of the effective theory in the future vacuum, a natural holographic criterion, automatically enforces the Trans-Planckian Censorship Conjecture (TCC) for classical cosmological solutions with positive potentials. Taken together, these constraints exclude the leading proposals to realize scale-separated AdS vacua and metastable de Sitter vacua in the string theory landscape such as DGKT and KKLT. - oai:arXiv.org:2511.15784v2 - hep-th - astro-ph.CO - gr-qc + Cosmic domain walls on a lattice: illusive effects of initial conditions + https://arxiv.org/abs/2509.25367 + arXiv:2509.25367v2 Announce Type: replace-cross +Abstract: Evolution of cosmic domain walls (DWs) settles to the scaling solution, which is often assumed to be independent of initial conditions. However, lattice simulations performed in this work reveal a clear dependence of the scaling DW area on the initial configuration of the sourcing scalar field, specifically, its infrared (IR) properties. Namely, the DW area grows as one suppresses IR modes in the initial scalar field spectrum. This growth is saturated, when the area parameter $\xi$ commonly used in the literature reaches the value $\xi_{max} \approx 1.2$. The dependence of $\xi$ on IR modes is argued to be of non-physical origin: it is likely to be due to effects of the lattice boundary. Assuming that physically the memory of initial conditions is erased, one recognizes $\xi \approx 1.2$ obtained in the situation with maximally suppressed IR modes as a genuine universal value of the area parameter in the scaling regime. We demonstrate that ignorance about initial conditions may affect predictions for the energy density of gravitational waves by the factor five. The spectral shape of gravitational waves is also affected by the choice of initial conditions, most notably in the low-frequency part. Likewise, we revisit annihilation of DWs under the influence of a potential bias. It has been previously found in Ref. [19] that the annihilation happens significantly earlier compared to the estimate based on the simple balance between the potential bias and surface energy density. We further support this observation and show that the tendency towards an earlier annihilation gets even stronger upon removing IR modes in simulations. + oai:arXiv.org:2509.25367v2 hep-ph - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.CO + hep-th + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by/4.0/ - Alek Bedroya, Paul J. Steinhardt + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + 10.1103/l9gp-7vp5 + Phys. Rev. D 112, 123521 (2025) + I. Dankovsky, S. Ramazanov, E. Babichev, D. Gorbunov, A. Vikman - Cosmological perturbations on an averaged background - https://arxiv.org/abs/2511.17160 - arXiv:2511.17160v2 Announce Type: replace-cross -Abstract: In relativistic cosmology, the formation of nonlinear inhomogeneities can induce non-negligible backreaction on late-time expansion. Among the important consequences for precision cosmology is the potential impact on the linear growth of large-scale structures. We address this impact by combining covariant spatial averaging with covariant and gauge-invariant perturbation theory. We focus on irrotational dust model spacetimes. The effects of backreaction and nontrivial dynamical curvature on the average cosmological dynamics are formulated as the addition of an effective perfect fluid with pressure. We then introduce an effective background driven by both the averaged dust density and the emergent effective fluid, and derive the general evolution equations for linear perturbations of this system. The residual freedom in this framework amounts to specifying the properties of the effective-fluid perturbations as a closure condition. We analyse two physically motivated choices for this condition. In addition, we clarify the conditions under which the coupling between linear structure growth and perturbations of the effective fluid can be neglected. Finally, we apply this formalism to four examples of averaged cosmological models from the literature, three of which -- intended as effective full descriptions of the largest scales -- have been shown to provide a good fit to observational data. Our results highlight the importance of backreaction effects in shaping linear structure growth in such models. Neglecting these effects may thus lead to biased predictions for the development of large structures, even when the models provide a good description of the general background observables. - oai:arXiv.org:2511.17160v2 + Bayesian power spectral density estimation for LISA noise based on P-splines with a parametric boost + https://arxiv.org/abs/2510.00533 + arXiv:2510.00533v2 Announce Type: replace-cross +Abstract: Flexible and accurate noise characterization is crucial for the precise estimation of gravitational-wave parameters. We introduce a Bayesian method for estimating the power spectral density (PSD) of long, stationary time series, explicitly tailored for LISA data analysis. Our approach models the PSD as the geometric mean of a parametric and a nonparametric component, combining the knowledge from parametric models with the flexibility to capture deviations from theoretical expectations. The nonparametric component is expressed by a mixture of penalized B-splines. Adaptive, data-driven knot placement, performed once at initialization, removes the need for reversible-jump Markov chain Monte Carlo, while hierarchical roughness-penalty priors prevent overfitting. Validation on simulated autoregressive AR(4) data demonstrates estimator consistency and shows that well-matched parametric components reduce the integrated absolute error compared to an uninformative baseline, requiring fewer spline knots to achieve comparable accuracy. Applied to one year of simulated LISA X-channel (univariate) noise, our method achieves relative integrated absolute errors of $\mathcal{O}(10^{-2})$, making it suitable for iterative analysis pipelines and multi-year mission data sets. + oai:arXiv.org:2510.00533v2 gr-qc - astro-ph.CO - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + physics.comp-ph + stat.CO + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by/4.0/ - Marco Galoppo, Pierre Mourier + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Nazeela Aimen, Patricio Maturana-Russel, Avi Vajpeyi, Nelson Christensen, Renate Meyer - A theory-agnostic hierarchical Bayesian framework for black-hole spectroscopy: a case study on GW250114 in Einstein-dilaton-Gauss-Bonnet gravity - https://arxiv.org/abs/2512.03713 - arXiv:2512.03713v2 Announce Type: replace-cross -Abstract: Black-hole spectroscopy has emerged as a powerful probe of strong-field gravity in the era of gravitational-wave astronomy. In this context, many current tests of modified or extended gravity are implemented by searching for predicted signatures modeled as perturbative corrections to general-relativistic waveforms; however, this approach may introduce model-dependent systematics and limit applicability to broader classes of theories. To complement such methods, we develop a theory-agnostic hierarchical Bayesian framework that connects ringdown observations -- modeled as damped sinusoids -- directly with theoretical quasinormal mode spectra, performing the comparison at the spectral level rather than through theory-specific waveform matching. The framework incorporates a soft-truncation module to account for the finite domain of validity in the theory's parameter space and is equipped with quantitative diagnostics that identify stable analysis time windows. As an illustrative application, we implement the framework within Einstein-dilaton-Gauss-Bonnet gravity and apply it to the gravitational-wave event GW250114, finding that the resulting posterior for the dimensionless coupling $\zeta$ is robust against prior assumptions yet remains only weakly informative over the range considered in this work. We further perform controlled ringdown injection studies across different values of $\zeta$, confirming that nonzero couplings can be recovered while also indicating a potential systematic effect: Kerr-based priors in the $\zeta$ inference may partially absorb spectral deviations arising in alternative theories of gravity. This work establishes a transparent and extensible foundation for future strong-field gravity tests, naturally compatible with the growing precision and modal resolution of next-generation gravitational-wave detectors. - oai:arXiv.org:2512.03713v2 + Photon counting readout for detection and inference of gravitational waves from neutron star merger remnants + https://arxiv.org/abs/2511.09656 + arXiv:2511.09656v2 Announce Type: replace-cross +Abstract: Gravitational waves emitted after neutron star binary coalescences and the information they carry about dense matter are a high-priority target for next-generation detectors. Even though such detectors are expected to observe millions of signals, detectable post-merger emission will remain rare. In this work, we explore post-merger detectability and inference through an alternative detector readout scheme for data dominated by quantum-noise, which is the case above $1$\,kHz: photon-counting. In such a readout, signals and noise become quantized into discrete distributions corresponding to the detection of single photons measured in a chosen basis of modes. Through simulated data, we demonstrate that photon counting can be efficient even for weak signals. We find ${\sim}1$ in 100 signals with a post-merger signal-to-noise ratio of 0.2 can result in a single photon and thus be detected. Furthermore, after $2\times10^4$ signals -- equivalent to $10^{-2}$ to $1.5$ years of observation -- photon counting results in a twofold improvement in the measurement of the radius of a $1.6\,M_\odot$ neutron star. Constraints can be further tightened if the detector classical noise is reduced. Photon counting offers a promising alternative to traditional homodyne readout techniques for extracting information from low signal-to-noise ratio post-merger signals. + oai:arXiv.org:2511.09656v2 gr-qc - astro-ph.HE - Wed, 10 Dec 2025 00:00:00 -0500 + astro-ph.IM + Thu, 11 Dec 2025 00:00:00 -0500 replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Shitong Guo, Yan-Gang Miao + http://creativecommons.org/licenses/by/4.0/ + Ethan Payne, Lee McCuller, Katerina Chatziioannou