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" @@ -7,1472 +7,12 @@ http://www.rssboard.org/rss-specification en-us - Fri, 16 Jan 2026 05:00:09 +0000 + Sun, 18 Jan 2026 05:00:17 +0000 rss-help@arxiv.org - Fri, 16 Jan 2026 00:00:00 -0500 + Sun, 18 Jan 2026 00:00:00 -0500 Sunday Saturday - - Habitable Worlds Observatory (HWO): Living Worlds Community Working Group: The Search for Life on Potentially Habitable Exoplanets - https://arxiv.org/abs/2601.09766 - arXiv:2601.09766v1 Announce Type: new -Abstract: The discovery of a biosphere on another planet would transform how we view ourselves, and our planet Earth, in relation to the rest of the cosmos. We now know Earth is one planet among eight circling our sun; our sun is part of a swirling galaxy of over one hundred billion other suns; and our galaxy is one of untold billions in the universe. While we do not yet know how many, if any, other biospheres exist on the countless worlds orbiting countless other suns, we stand at the precipice of a new era of discovery, enabled by powerful new facilities able to peer across the light years into the atmospheres of planets similar to our own. This article is an adaptation of a science case document (SCDD) developed for the NASA Astrophysics Flagship mission the Habitable Worlds Observatory (HWO) Science, Technology, and Architecture Review Team (START) Living Worlds Community Working Group. - oai:arXiv.org:2601.09766v1 - astro-ph.IM - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Giada Arney, Niki Parenteau, Natalie Hinkel, Eric Mamajek, Joshua Krissansen-Totton, Stephanie Olson, Edward Schwieterman, Sara Walker, Kevin Fogarty, Ravi Kopparapu, Jacob Lustig-Yaeger, Mark Moussa, Sukrit Ranjan, Garima Singh, Clara Sousa-Silva, Ruslan Belikov, Maxwell Frissell, Samantha Gilbert-Janziek, Vincent Kofman, Natasha Latouf, Mary Anne Limbach, Rhonda Morgan, Christopher Stark, Armen Tokadjian, Anna Grace Ulses, Nicholas Wogan, Mike Wong, Amber Young - - - CLiMB: A Domain-Informed Novelty Detection Clustering Framework for Scientific Discovery - https://arxiv.org/abs/2601.09768 - arXiv:2601.09768v1 Announce Type: new -Abstract: In data-driven scientific discovery, a challenge lies in classifying well-characterized phenomena while identifying novel anomalies. Current semi-supervised clustering algorithms do not always fully address this duality, often assuming that supervisory signals are globally representative. Consequently, methods often enforce rigid constraints that suppress unanticipated patterns or require a pre-specified number of clusters, rendering them ineffective for genuine novelty detection. To bridge this gap, we introduce CLiMB (CLustering in Multiphase Boundaries), a domain-informed framework decoupling the exploitation of prior knowledge from the exploration of unknown structures. Using a sequential two-phase approach, CLiMB first anchors known clusters using constrained partitioning, and subsequently applies density-based clustering to residual data to reveal arbitrary topologies. We demonstrate this framework on RR Lyrae stars data from the Gaia Data Release 3. CLiMB attains an Adjusted Rand Index of 0.829 with 90% seed coverage in recovering known Milky Way substructures, drastically outperforming heuristic and constraint-based baselines, which stagnate below 0.20. Furthermore, sensitivity analysis confirms CLiMB's superior data efficiency, showing monotonic improvement as knowledge increases. Finally, the framework successfully isolates three dynamical features (Shiva, Shakti, and the Galactic Disk) in the unlabelled field, validating its potential for scientific discovery. - oai:arXiv.org:2601.09768v1 - astro-ph.IM - astro-ph.GA - cs.AI - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Lorenzo Monti, Tatiana Muraveva, Brian Sheridan, Davide Massari, Alessia Garofalo, Gisella Clementini, Umberto Michelucci - - - The X-Ray Dot: Exotic Dust or a Late-Stage Little Red Dot? - https://arxiv.org/abs/2601.09778 - arXiv:2601.09778v1 Announce Type: new -Abstract: JWST's "Little Red Dots" (LRDs) are increasingly interpreted as active galactic nuclei (AGN) obscured by dense thermalized gas rather than dust as evidenced by their X-ray weakness, blackbody-like continua, and Balmer line profiles. A key question is how LRDs connect to standard UV-luminous AGN and whether transitional phases exist and if they are observable. We present the "X-Ray Dot" (XRD), a compact source at $z=3.28$ observed by the NIRSpec WIDE GTO survey. The XRD exhibits LRD hallmarks: a blackbody-like ($T_{\rm eff} \simeq 6400\,$K) red continuum, a faint but blue rest-UV excess, falling mid-IR emission, and broad Balmer lines ($\rm FWHM \sim 2700-3200\,km\,s^{-1}$). Unlike LRDs, however, it is remarkably X-ray luminous ($L_\textrm{2$-$10$\,$keV} = 10^{44.18}\,$erg$\,$s$^{-1}$) and has a continuum inflection that is bluewards of the Balmer limit. We find that the red rest-optical and blue mid-IR continuum cannot be reproduced by standard dust-attenuated AGN models without invoking extremely steep extinction curves, nor can the weak mid-IR emission be reconciled with well-established X-ray--torus scaling relations. We therefore consider an alternative scenario: the XRD may be an LRD in transition, where the gas envelope dominates the optical continuum but optically thin sightlines allow X-rays to escape. The XRD may thus provide a physical link between LRDs and standard AGN, offering direct evidence that LRDs are powered by supermassive black holes and providing insight into their accretion properties. - oai:arXiv.org:2601.09778v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Raphael E. Hviding, Anna de Graaff, Hanpu Liu, Andy D. Goulding, Yilun Ma, Jenny E. Greene, Leindert A. Boogaard, Andrew J. Bunker, Nikko J. Cleri, Marijn Franx, Michaela Hirschmann, Joel Leja, Rohan P. Naidu, Jorryt Matthee, David J. Setton, Hannah \"Ubler, Giacomo Venturi, Bingjie Wang - - - Breathless BEARS: [O$_{\rm \,III}$] 88$\mu$m Emission of Dusty Star-Forming Galaxies at $z = 3-4$ - https://arxiv.org/abs/2601.09780 - arXiv:2601.09780v1 Announce Type: new -Abstract: We present [O$_{\rm \,III}$] 88$\mu$m observations towards four ${\it Herschel}$-selected dusty star-forming galaxies (DSFGs; log$_{10}$ $\mu$L$_{\rm IR}$/L$_{\odot}$ = 13.5 - 14 at $z = 2.9 - 4$) using the Atacama Compact Array (ACA) in Bands 9 and 10. We detect [O$_{\rm \,III}$] emission in all four targets at >3$\sigma$, finding line luminosity ratios ($L_{\rm [O_{\rm \,III}]}$ / L$_{\rm IR}$ = 10$^{-4.2}$ to 10$^{-3}$) similar to local spiral galaxies, and an order of magnitude lower when compared with local dwarf galaxies as well as high-redshift Lyman-break galaxies. Using the short-wavelength capabilities of the ACA, these observations bridge the populations of galaxies with [O$_{\rm \,III}$] emission at low redshift from space missions and at high redshift from ground-based studies. The difference in [O$_{\rm \,III}$] emission between these DSFGs and other high-redshift galaxies reflects their more evolved stellar populations (> 10 Myr), larger dust reservoirs (M$_{\rm dust}$ $\sim$ 10$^{9 - 11}$ M$_{\odot}$), metal-rich interstellar medium ($Z \sim 0.5 - 2$ Z$_{\odot}$), and likely weaker ionization radiation fields. Ancillary [C$_{\rm \,II}$] emission on two targets provide $L_{[{\rm O}_{\rm \,III}]} / L_{[{\rm C}_{\rm \,II}]}$ ratios at 0.3 - 0.9, suggesting that ionized gas represents a smaller fraction of the total gas reservoir in DSFGs, consistent with theoretical models of DSFGs as transitional systems between gas-rich, turbulent disks and more evolved, gas-poor galaxies. Expanding samples of DSFGs with [O$_{\rm \,III}$] emission will be key to place this heterogeneous, poorly-understood galactic phase in its astrophysical context. - oai:arXiv.org:2601.09780v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - T. J. L. C. Bakx, Hiddo S. B. Algera, Prachi Prajapati, George Bendo, Stefano Berta, Laura Bonavera, Pierre Cox, Joaquin Gonz\'alez-Nuevo, Masato Hagimoto, Kevin Harrington, Matthew Lehnert, Stephen Serjeant, Pasquale Temi, Paul van der Werf, Chentao Yang, Gianfranco De Zotti - - - New Hard X-Ray and Multiwavelength Study of the PeVatron Candidate PWN G0.9+0.1 in the Galactic Center Region - https://arxiv.org/abs/2601.09788 - arXiv:2601.09788v1 Announce Type: new -Abstract: We present a new X-ray study and multiwavelength spectral energy distribution (SED) modeling of the young pulsar wind nebula (PWN) powered by the energetic pulsar PSR J1747-2809, inside the composite supernova remnant (SNR) G0.9+0.1, located in the Galactic Center region. The source is detected by NuSTAR up to 30 keV with evidence for the synchrotron burnoff effect in the changing spatial morphology with increasing energy. The broadband 2-30 keV spectrum of PWN G0.9+0.1 is modeled by a single power law with photon index $\Gamma=2.11\pm0.07$. We combined the new X-ray data with the multiwavelength observations in radio, GeV, and TeV gamma rays and modeled the SED, applying a one-zone and a multi-zone leptonic model. The comparison of the models is successful, as we obtained physically compatible results in the two cases. Through the one-zone model, we constrain the age of the system to $\sim2.2$ kyr, as well as reproduce the observed PWN and SNR radio sizes. In both the one-zone and multi-zone leptonic models, the electron injection spectrum is well-described by a single power law with spectral index $p \sim 2.6$ and a maximum electron energy of $\sim2$ PeV, suggesting the source could be a leptonic PeVatron candidate. We estimate the average magnetic field to be $B_{\rm PWN} \sim 20\ \mu$G. We also report the serendipitous NuSTAR detection of renewed X-ray activity from the very faint X-ray transient XMMU J174716.1-281048 and characterize its spectrum. - oai:arXiv.org:2601.09788v1 - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Giulia Brunelli, Kaya Mori, Jaegeun Park, Jordan Eagle, Moaz Abdelmaguid, Melania Nynka, Hongjun An, Aya Bamba, Joseph D. Gelfand, Gabriele Ponti, Samar Safi-Harb, Vito Sguera, Cristian Vignali, Jooyun Woo, Roberta Zanin - - - Growing in number, passive in nature: tracing the evolution of the most massive quiescent galaxies since z ~ 0.8 with BOSS and DESI - https://arxiv.org/abs/2601.09789 - arXiv:2601.09789v1 Announce Type: new -Abstract: Luminous Red Galaxies (LRGs) are among the most massive galaxies at any epoch, and lack ongoing star formation. As systems hosting most of the baryonic mass in the local Universe, they preserve imprints of the quenching mechanisms in the early Universe. We exploited the large BOSS and DESI spectroscopic datasets to perform the first homogeneous and continuous mapping of the evolution of stellar population properties of a complete sample of the most massive LRGs ($\log (M_*/\mathrm{M_\odot})> 11.5$) at 0.15 < z < 0.8. By consistently fitting the same spectral indices at all redshifts, we measured trends of [Fe/H], [alpha/Fe], and light-weighted age as a function of redshift. These galaxies exhibit a passive light-weighted age evolution and flat [Fe/H] and [alpha/Fe] trends towards lower redshift, indicating genuinely passive evolution. These trends are robust against the choice of stellar population models and analysis assumptions, and they support the predictions from IllustrisTNG, which predict negligible chemical evolution for the most massive quenched systems at z < 0.8. Our results suggest that, despite nearly 5 Gyr of cosmic time and a 3-4x increase in number density, the stellar population properties of massive quiescent galaxies remain essentially unchanged since z ~ 0.8. This shows a negligible progenitor bias below z ~ 0.8, and a genuinely passive evolution. Newly added systems after $z \sim 0.8$ were already largely quenched and chemically mature, while subsequent evolution was dominated by dry mergers without altering the bulk of the stellar populations. - oai:arXiv.org:2601.09789v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - F. R. Ditrani, M. Fossati, M. Longhetti, F. La Barbera, A. Iovino, C. Maraston, D. Thomas, D. Bevacqua - - - The influence of magnetic fields in Cloud-Cloud Collisions - https://arxiv.org/abs/2601.09794 - arXiv:2601.09794v1 Announce Type: new -Abstract: Cloud-cloud collisions are expected to trigger star formation by compressing gas into dense, gravitationally unstable regions. However, the role of magnetic fields in this process is unclear. We use SPH to model head-on collisions between two uniform density clouds, each with mass $500 \,$M$_{\odot}$, initial radius 2 pc, and embedded in a uniform magnetic field parallel to the collision velocity. As in the nonmagnetic case, the resulting shock-compressed layer fragments into a network of filaments. If the collision is sufficiently slow, the filaments are dragged into radial orientations by non-homologous gravitational contraction, resulting in a $\textit{Hub Filament}$ morphology, which spawns a centrally concentrated monolithic cluster with a broad mass function shaped by competitive accretion and dynamical ejections. If the collision is faster, a $\textit{Spiders Web}$ of intersecting filaments forms, and star-systems condense out in small subclusters, often at the filament intersections; due to their smaller mass reservoirs, and the lower probability of dynamical ejection, the mass function of star-systems formed in these subclusters is narrower. Magnetic fields affect this dichotomy quantitatively by delaying collapse and fragmentation. As a result, the velocity threshold separating $\textit{Hub Filament}$ and $\textit{Spiders Web}$ morphologies is shifted upward in magnetised runs, thereby enlarging the parameter space in which $\textit{Hub Filament}$ morphologies form, and enhancing the likelihood of producing centrally concentrated clusters. Consequently, magnetic fields regulate both the morphology and timing of star formation in cloud-cloud collisions: they broaden filaments, delay the onset of star formation, and promote the formation of $\textit{Hub Filament}$ morphologies, monolithic clusters and high-mass star-systems. - oai:arXiv.org:2601.09794v1 - astro-ph.GA - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Theotokis Georgatos, AnthonyP. Whitworth - - - HR-GO II: chemical abundances of low-$E$ retrograde dynamically-tagged-groups: Revealing Thamnos as a very metal-poor substructure - https://arxiv.org/abs/2601.09796 - arXiv:2601.09796v1 Announce Type: new -Abstract: Milky Way halo substructures identified in dynamical space are known to suffer from contamination from the Milky Way in-situ stars, which makes their accreted origins uncertain. We present detailed chemical abundances of 35 stars belonging to two sets of dynamically tagged groups, Rg8 and Rg9, to investigate their accreted nature. Both groups are composed of stars with low orbital energy and very retrograde orbits. We find that Rg8 and Rg9 are chemically indistinguishable across all elements, from C to Eu, strongly indicating that they belong to the same structure. The iron-abundance distribution of this low-$E$ retrograde group has a prominent peak at [Fe/H] $\approx-2.1$, revealing that its main population is very metal-poor, and a secondary peak at [Fe/H] $\approx-1.5$, very likely due to contamination from Milky Way in-situ stars. These groups also heavily overlap with the Thamnos substructure in dynamical space, and we thus use them to investigate the chemical properties of Thamnos. The dominant, low-metallicity population provides strong evidence for the ex-situ origin of Thamnos, as well as its very metal-poor nature. We do not see any evidence of an $\alpha$ knee in our sample, which is consistent with previous studies. Comparison with the Cetus-Palca stream in the chemical space shows similar abundance distributions, and thus it suggests that the Thamnos progenitor dwarf galaxy had a truncated star formation history due to its early merger with the Milky Way. - oai:arXiv.org:2601.09796v1 - astro-ph.GA - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Renjing Xie, Zhen Yuan, Haining Li, Tadafumi Matsuno, Nicolas F. Martin, Ruizhi Zhang, Zhiqiang Yan, Federico Sestito, Guillaume F. Thomas, Projjwal Banerjee, Ruizheng Jiang, Linda Lombardo, David S. Aguado, Kohei Hattori, Gang Zhao - - - Stellar-wind Fueled Accretion onto Sagittarius A* in the Presence of a Nuclear Star Cluster - https://arxiv.org/abs/2601.09799 - arXiv:2601.09799v1 Announce Type: new -Abstract: The Milky Way's Galactic Center hosts the black hole Sagittarius A* (Sgr A*), which provides us with a close-up view into supermassive black hole accretion and feedback. Recent works have shown that the winds from $\sim 30$ Wolf-Rayet (WR) stars orbiting Sgr A* at about 4 arcsec are important contributors to feeding the supermassive black hole. A nuclear star cluster (NSC) with a mass of several $10^6 \, \text{M}_\odot$, of which $10^6 \, \text{M}_\odot$ is within 1 pc, also surrounds Sgr A*. The NSC contributes to the gravitational potential in the Galactic Center, affecting the orbits of the WR stars and their stellar winds. In this work, we examine the effects that the NSC has on the accretion of these stellar winds onto Sgr A* which have previously been neglected. We find that, on the parsec scale, the effect from the gravitational potential of the NSC is negligible on the wind-fed accretion flow, validating the existing simulations used in the literature. - oai:arXiv.org:2601.09799v1 - astro-ph.HE - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Edward Skrabacz, Lena Murchikova, Sean M. Ressler, Asad Ukani, Siddhant Solanki - - - Dark energy driven by an oscillating generalised axion-like quintessence field - https://arxiv.org/abs/2601.09803 - arXiv:2601.09803v1 Announce Type: new -Abstract: Generalised axion-like scalar fields provide a well-motivated framework for describing the late-time acceleration of the Universe. As the field evolves, it rolls down its potential and, depending on its mass and initial conditions, it may either still be approaching the minimum or already oscillating around it. These two dynamical regimes require distinct treatments of cosmological perturbations. In this work, we perform a detailed analysis of linear cosmological perturbations in the regime where the dark-energy scalar field undergoes coherent oscillations about the minimum of its potential. We show that the standard effective fluid description breaks down in this phase and develop a consistent field-based perturbation framework, which we use to assess the impact of oscillatory dark energy on the growth of cosmic structures. - oai:arXiv.org:2601.09803v1 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Mariam Bouhmadi-L\'opez, Carlos G. Boiza - - - Simulating the photospheric to coronal plasma using magnetohydrodynamic characteristics III: validation including gravity, flux emergence, and an eruption - https://arxiv.org/abs/2601.09804 - arXiv:2601.09804v1 Announce Type: new -Abstract: Solar eruptions arise from instabilities or loss of equilibria in the solar atmosphere, but routinely inferring the precise magnetic and plasma properties that lead to eruptions is not currently practical using synoptic solar observations. Data driven simulations offer an appealing alternative. We test our boundary data-driven magnetohydrodynamic (MHD) approach, based on the method of characteristics, on a simulation that includes full MHD, a stratified atmosphere, and the emergence of a model solar magnetic active region, from the photosphere upwards. The driven simulation is tested against a larger, ab initio ``Ground Truth'' simulation that extends downward into the convection zone. Our driven simulation accurately reproduces the dynamic emergence of the active region above the photosphere, the formation of key topological features throughout the corona, and the subsequent eruption of mass and magnetic field. The total emerged energy matches to better than one percent, the ratio of emerged to eruptive energy is $\approx2\%$, and the actual values of each energy term agree to within $10\%$ between the two cases. Crucially, the data injection cadence, when properly scaled, matches the cadence of synoptic observations of the Sun's surface magnetic field, and is three to four orders of magnitude longer than the inherent CFL time step of the simulations. The stability of the code and fidelity of the results over an entire active region lifetime, from emergence to eruption, strongly suggests that our method will produce reliable results when driven using solar synoptic observations from existing and anticipated ground and spaced based observatories. - oai:arXiv.org:2601.09804v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Lucas A. Tarr, N. Dylan Kee, James E. Leake, Mark G. Linton, Peter W. Schuck - - - Magnetic Pumping: Plasma Heating to Particle Acceleration - https://arxiv.org/abs/2601.09807 - arXiv:2601.09807v1 Announce Type: new -Abstract: One of the earliest mechanisms proposed for plasma heating was magnetic pumping (MP). However, its significance for astrophysical phenomena, including particle acceleration, has yet to be appreciated. MP-energized particles tap energy from magnetic-field oscillations. A particle's momentum component perpendicular to the local B-field increases during field growth by virtue of the adiabatic invariant $p_{\perp}^{2}/B=const$. The gained $p_{\perp}$ is then partially scattered elastically into the parallel momentum, $p_{\parallel}$, with $p^{2}=p_{\parallel}^{2}+p_{\perp}^{2}=const$, thereby retaining some fraction of the gained energy before the field decreases to its minimum. This scattering breaks the reversibility of energy exchange between particles and oscillating magnetic fields, thereby increasing the particle energy after each MP cycle. Field oscillations are often assumed to be sinusoidal, and the resulting MP is treated perturbatively. These simplifications restrict astrophysical applications, leaving objects with strong magnetic perturbations outside the scope of adequate treatment. We develop a nonperturbative approach to MP that is suitable for a broad spectrum of magnetic turbulence. The treatment comprises two steps. The first step is common: converting a kinetic equation into an infinite hierarchy of moments of the particle distribution function. The second step is new in MP treatments: we find an exact closure at an arbitrary level of the moment system. The heating is treated exactly at the second-moment closure. Particle acceleration generally requires a higher-level closure to determine the power-law index and the maximum energy of accelerated particles. We propose a method for extracting these crucial acceleration data from the second moment for a broadband random field. - oai:arXiv.org:2601.09807v1 - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Mikhail Malkov, Immanuel Jebaraj - - - Calibrating Mid-Infrared Emission Features As Diagnostics of Star Formation in Infrared-Luminous Galaxies via Radiative Transfer Modeling - https://arxiv.org/abs/2601.09810 - arXiv:2601.09810v1 Announce Type: new -Abstract: Luminous infrared galaxies are key sites of obscured stellar mass assembly at z > 0.5. Their star formation rates (SFRs) are often estimated using the luminosities of the 6.2 micron and 11.2 micron polycyclic aromatic hydrocarbon (PAH) features, or those of the [Ne II] and [Ne III] fine-structure lines, as they are minimally affected by obscuration. It is uncertain whether the calibration of these features as SFR tracers depends on the starburst bolometric luminosity or the level of Active Galactic Nucleus (AGN) activity. We here investigate the relationship between the luminosities of PAH and Neon lines with star formation rate for highly luminous objects using radiative transfer modeling and archival observations of 42 local Ultraluminous (>= 10^12 L_sun) Infrared Galaxies (ULIRGs). We find that PAH and [Ne II] features arise mainly in star-forming regions, with small contributions from the AGN or host, but that the [Ne III] line has a mixed contribution from both star formation and AGN activity. We present relations between L_PAH and L_NeII, and both starburst luminosity and SFR. We find relations for lower luminosity (L_IR ~= 10^10-10^12 L_sun) systems underestimate the SFRs in local ULIRGs by up to ~1 dex. The 6.2 micron and 11.2 micron PAH features, and the [Ne II] line, are thus good tracers of SFR in ULIRGs. We do not find that a more luminous AGN affects the relationship between SFR and PAH or Neon luminosity, but that it can make PAH emission harder to discern. Our results and derived relations are relevant to studies of star-forming and composite galaxies at z < 3 with the James Webb Space Telescope. - oai:arXiv.org:2601.09810v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - L. Robinson (Department of Astronomy, University of Wisconsin-Madison), D. Farrah (Department of Physics and Astronomy, University of Hawaii at Manoa, Institute for Astronomy, University of Hawaii), A. Efstathiou (School of Sciences, European University Cyprus), A. Engholm (Department of Physics and Astronomy, University of Hawaii at Manoa, Institute for Astronomy, University of Hawaii), E. Hatziminaoglou (European Southern Observatory, Instituto de Astrofisica de Canarias, Universidad de La Laguna, Opto. Astrofisica), M. Joyce (Michigan State University), V. Lebouteiller (Universite Paris-Saclay and Universite Paris Cite), S. Petty (NorthWest Research Associates), L. K. Pitchford (Department of Physics and Astronomy, Texas A&M University, George & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University), J. Afonso (Instituto de Astrof{\i}sica e Ciencias do Espaco, Universidade de Lisboa, Departamento de Fisica, Faculdade de Ciencias, Universidade de Lisboa), D. Clements (Imperial College London), M. Lacy (National Radio Astronomy Observatory), C. Pearson (RAL Space, STFC Rutherford Appleton Laboratory, The Open University, Oxford Astrophysics, University of Oxford), D. Rigopoulou (Oxford Astrophysics, University of Oxford), M. Rowan-Robinson (Imperial College London), L. Wang (SRON Netherlands Institute for Space Research, Kapteyn Astronomical Institute, University of Groningen) - - - A Robust Launching Mechanism for Freely-Floating Planets from Host Stars with Close-in Planets - https://arxiv.org/abs/2601.09835 - arXiv:2601.09835v1 Announce Type: new -Abstract: Secular perturbations from binary stars and distant massive planets can drive cold planets onto nearly parabolic orbits with pericenter passages extremely close to their host stars. Meanwhile, short-period super-Earths are frequently observed around nearby stars. Gravitational scattering between these two distinct populations can lead to substantial orbital energy exchange, liberating some intruders from the gravitational confinement of their host systems. This process offers a robust formation channel for a subset of the abundant freely floating planet population. It may also significantly perturb the original orbits of close-in planets, induce collisional trajectories between close-in planets and their host stars, and disrupt the dynamical evolution of cold planets toward close stellar encounters. - oai:arXiv.org:2601.09835v1 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xiaochen Zheng, Zhuoya Cao, Shigeru Ida, Douglas N. C. Lin, Shude Mao - - - The formation of periodic three-body orbits for Newtonian systems - https://arxiv.org/abs/2601.09843 - arXiv:2601.09843v1 Announce Type: new -Abstract: Braids are periodic solutions to the general N-body problem in gravitational dynamics. These solutions seem special and unique, but they may result from rather usual encounters between four bodies. We aim at understanding the existence of braids in the Galaxy by reverse engineering the interactions in which they formed. We simulate self-gravitating systems of N particles, starting with the constructing of a specific braid, and bombard it with a single object. We study how frequently the bombarded braid dissolves in four singles, a triple and a single, a binary and 2 singles, or 2 binaries. The relative proportion of those events gives us insight into how easy it is to generate a braid through the reverse process. It turns out that braids are easily generated from encounters between 2 binaries, or a triple with a single object, independent on the braid's stability. We find that 3 of the explored braids are linearly stable against small perturbations, whereas one is unstable and short-lived. The shortest-lived braid appears the least stable and the most chaotic. nonplanar encounters also lead to braid formation, which, in our experiments, themselves are planar. The parameter space in azimuth and polar angle that lead to braid formation via binary-binary or triple-single encounters is anisotropic, and the distribution has a low fractal dimension. Since a substantial fraction of ~9% of our calculations lead to periodic 3-body systems, braids may be more common than expected. They could form in multi-body interactions. We do not expect many to exist for time, but they may be common as transients, as they survive for tens to hundreds of periodic orbits. We argue that braids are common in relatively shallow-potential background fields, such as the Oort cloud or the Galactic halo. If composed of compact objects, they potentially form interesting targets for gravitational wave detectors. - oai:arXiv.org:2601.09843v1 - astro-ph.GA - astro-ph.IM - math-ph - math.MP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Simon Portegies Zwart, Arjen Doelman, Jelmer Sein - - - Are Recently Quenched Ellipticals Truly Isolated Centrals? - https://arxiv.org/abs/2601.09846 - arXiv:2601.09846v1 Announce Type: new -Abstract: Recently Quenched Ellipticals (RQEs) provide a valuable test case for disentangling intrinsic and environmental quenching, particularly because they are commonly classified as isolated central galaxies in low-mass halos. However, central/satellite assignments and isolation labels can vary across group catalogs, and such misclassifications can strongly bias physical interpretations. We present a uniform, physically motivated reassessment of the environments of 155 RQEs previously identified as centrals in an SDSS-based group catalog. We construct value-added neighbor catalogs via KD-tree searches and apply consistent thresholds in projected separation and line-of-sight velocity to (i) verify centrality, (ii) quantify isolation using a mass-ratio-based companion criterion, and (iii) identify potential pseudo-centrals via proximity to massive clusters. We find that 132/155 (85.2\%) RQEs remain true centrals, while 23/155 (14.8\%) are better interpreted as misidentified centrals with a more massive neighbor within $R_{\rm proj}\leq0.8$~Mpc and $\Delta V\leq250$~km~s$^{-1}$. Among the true centrals, 110/132 (83.3\%) satisfy our isolation criterion, and only one system meets our pseudo-central definition, indicating that direct cluster-scale preprocessing is rare for RQE centrals. Using projected number density and surface stellar mass density, we show that misidentified and non-isolated systems occupy systematically denser regimes than isolated true centrals. These results imply that while most RQEs ($\sim$71\%) are consistent with predominantly internal quenching in genuinely isolated centrals, a non-negligible minority ($\sim$29\%) likely experienced environmentally influenced pathways at group scales. - oai:arXiv.org:2601.09846v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Deepak K. Deo - - - Gravitational Wave Strain and Orbital Dynamics of Binary Pulsars from LIGO-Virgo to LISA - https://arxiv.org/abs/2601.09863 - arXiv:2601.09863v1 Announce Type: new -Abstract: We summarize the current state of the art and calculate gravitational wave strain amplitudes for known binary pulsars, using data from current ground-based detectors (LIGO-Virgo-KAGRA) and the upcoming space-based missions (LISA). We present detailed calculations of the characteristic gravitational wave strain values, ranging from 3.0 to 73 $\times10^{-22}$, across frequencies between 0.66 and 5.87 $\times10^{-4}$ Hz. Our post-Newtonian approximation analysis yields predicted periastron advance rates from 1.6 to 80.5 deg/yr and orbital period decay rates between -5 and -176 $\mu$s/yr for the binary pulsar population. We derive common envelope efficiency parameters ($\alpha_{CE}$) for representative progenitor scenarios within our sample, finding values between 0.63 and 1.16, with notable sensitivity to the binding energy parameter $\lambda$. Binary neutron star merger rates are estimated at $22.77^{+6.83}_{-6.83}$ Myr$^{-1}$ for the Milky Way, corresponding to a volumetric rate of $227.71^{+68.31}_{-68.31}$ Gpc$^{-3}$ yr$^{-1}$, consistent with the latest LIGO-Virgo-KAGRA observational constraints. Our results illustrate how multi-band gravitational wave observations, from LIGO/Virgo to LISA, can contribute to precise measurements of binary pulsar strain and orbital evolution histories, improving merger time predictions and constraining neutron star physics and common envelope processes - oai:arXiv.org:2601.09863v1 - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 10.1140/epjp/s13360-025-07084-4 - The European Physical Journal Plus 141, 2026, (1), 21 - Ali Taani - - - Dynamics of Apsidal Motion in Non-Synchronous Binary Pulsars Coupled Orbit and Spin Evolution - https://arxiv.org/abs/2601.09868 - arXiv:2601.09868v1 Announce Type: new -Abstract: The apsidal motion of a non-synchronous binary pulsar serves as a valuable probe of relativistic gravity, stellar stricture, and dynamical evolution of close binary systems, In this study, we investigate the combined influence of general relativity, stellar oblateness and tidal interaction on the apsidal motion of three binary pulsars: 1913+16, J0737-3039A/B, and J0621+1002. Zahn's tidal equations \cite{1977A&A....57..383Z, 1989A&A...220..112Z} were employed for numerical integrations to describe tidal effects and their role in orbital and spin evolution. We estimated the timescales for tidal synchronization and orbital circularization for each system. The results indicate that tidal effects play only a minor role in orbital decay compared with energy loss due to gravitational wave emission. This is evident in the compact system PSR 1913+16, where the orbital period decreases by approximately 76.5 $\mu$s/yr as a result of gravitational radiation. The double pulsar J0737-3039A/B exhibits faster orbital evolution, with synchronization occurring in about 8.4$\times10{^3}$ years, whereas the wider system J0621+1002 shows negligible orbital change over timescales exceeding 10$^{10}$ years. The simulations demonstrate clear trends of decreasing semi-major axis and eccentricity, accompanied by an increase in spin rate among the binary pulsars studied. The derived apsidal motion constants [$k\simeq0.1$] are consistent with theoretical expected values, and the corresponding tidal friction times (between a few hours to several days) agree well with theoretical predication. These results emphasize the dominant role of relativistic effects in neutron star binaries and highlight the importance of including gravitational-wave terms long-term orbital evolution - oai:arXiv.org:2601.09868v1 - astro-ph.HE - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 0.1007/s10509-025-04518-4 - Published by Astrophysics and Space Science, 2025, 370, (11), 128 - Ali Taani - - - Monitoring of Continuous-Wave Hardware Injections in LIGO Interferometers during the O4 Observing Run - https://arxiv.org/abs/2601.09918 - arXiv:2601.09918v1 Announce Type: new -Abstract: Although there have now been hundreds of transient gravitational-wave detections of merging compact stars by the LIGO-Virgo-KAGRA (LVK) detector network, no continuous-wave (CW) signals have yet been discovered. To ensure that such signals, expected to be exceedingly weak, can be detected in the ongoing O4 observing run by coherent integration over years, simulated waveforms ('hardware injections') are injected directly into the LIGO data by continuously modulating the positions of the interferometer mirrors so as to mimic nearly sinusoidal signals from fast-spinning galactic neutron stars. A set of 18 such simulated CW sources are injected with signal frequencies spanning much of the LIGO detection band and with varying sky locations. By verifying the successful recovery of the simulated signals, including preservation of absolute phase over as many as 10^{11} signal cycles, we validate our understanding of detector response and end-to-end search pipelines, including data cleaning. Daily and weekly monitoring of the signal reconstruction is meant to catch any unexpected sudden changes in interferometer response, to verify that signal-to-noise ratio increases as expected and to verify that simulated source parameters are recovered correctly. We describe three methods of monitoring: 1) a highly templated matched filter to extract signal amplitude and phase precisely; 2) a frequentist Fstatistic evaluation that marginalizes over amplitude, phase and orientation of the star; and 3) a Bayesian reconstruction of the source parameters together with noise characterization. Results from each method are shown, with emphasis on the new templated method, which yields precise measurement of the critical phase offset parameter and therefore validates understanding of absolute timing delays in the detector response and data stream. - oai:arXiv.org:2601.09918v1 - astro-ph.IM - gr-qc - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Preet Baxi, Jessica Leviton, Eilam Morag, Matthew Pitkin, Keith Riles - - - Beyond UV: Rest-frame B-band and Apparent Luminosity Functions of z=5-9 Galaxies - https://arxiv.org/abs/2601.09948 - arXiv:2601.09948v1 Announce Type: new -Abstract: We present new measurements of galaxy luminosity functions (LFs) from JWST/NIRCam imaging over the redshift range z=4.5-9.7, using photometric catalogs from JADES and public extragalactic fields. Our analysis includes rest-frame UV and B-band LFs, as well as apparent LFs in F090W, F115W, F200W, F356W, and F444W. We present the first constraints on the rest-frame B-band LF at z~7-8 and extend existing measurements at z~5 to M(B) = -18 mag. The B-band LFs evolve more strongly with redshift than UV LFs, though both decline more gradually than predicted by simulations at z>5. No single existing simulation reproduces all observed trends, with discrepancies likely driven by assumptions about binary evolution and stellar population synthesis models. The apparent LFs in F356W and F444W show hints of a bright-end excess at all redshifts, extending to fainter magnitudes at higher redshift. While extreme emission line galaxies may partially account for it, the excess may also indicate a population of moderately red, optically bright sources - potentially dusty star-forming galaxies or obscured AGNs. Finally, we find that rest-frame B-band luminosity correlates more tightly with stellar mass than UV, making it a powerful tracer of mass assembly and reinforcing the diagnostic value of rest-frame optical LFs in uncovering the physical processes that drive early galaxy formation. - oai:arXiv.org:2601.09948v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Nicha Leethochawalit, Takahiro Morishita, Tirawut Worrakitpoonpon, Michele Trenti - - - What Understanding Means in AI-Laden Astronomy - https://arxiv.org/abs/2601.10038 - arXiv:2601.10038v1 Announce Type: new -Abstract: Artificial intelligence is rapidly transforming astronomical research, yet the scientific community has largely treated this transformation as an engineering challenge rather than an epistemological one. This perspective article argues that philosophy of science offers essential tools for navigating AI's integration into astronomy--conceptual clarity about what "understanding" means, critical examination of assumptions about data and discovery, and frameworks for evaluating AI's roles across different research contexts. Drawing on an interdisciplinary workshop convening astronomers, philosophers, and computer scientists, we identify several tensions. First, the narrative that AI will "derive fundamental physics" from data misconstrues contemporary astronomy as equation-derivation rather than the observation-driven enterprise it is. Second, scientific understanding involves more than prediction--it requires narrative construction, contextual judgment, and communicative achievement that current AI architectures struggle to provide. Third, because narrative and judgment matter, human peer review remains essential--yet AI-generated content flooding the literature threatens our capacity to identify genuine insight. Fourth, while AI excels at well-defined problem-solving, the ill-defined problem-finding that drives breakthroughs appears to require capacities beyond pattern recognition. Fifth, as AI accelerates what is feasible, pursuitworthiness criteria risk shifting toward what AI makes easy rather than what is genuinely important. We propose "pragmatic understanding" as a framework for integration--recognizing AI as a tool that extends human cognition while requiring new norms for validation and epistemic evaluation. Engaging with these questions now may help the community shape the transformation rather than merely react to it. - oai:arXiv.org:2601.10038v1 - astro-ph.IM - cs.AI - cs.LG - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yuan-Sen Ting, Andr\'e Curtis-Trudel, Siyu Yao - - - Caught in Swallowtails: Discovery of Two Swallowtail Image Formations in MS 0451.6-0305 - https://arxiv.org/abs/2601.10097 - arXiv:2601.10097v1 Announce Type: new -Abstract: We report the discovery of two swallowtail image formations at $z=2.91$ and $z=6.70$ behind the galaxy cluster MS 0451.6-0305 in JWST-NIRCam imaging. We find that in both of the above lensed systems, the complex image morphology cannot be reproduced by simple fold/cusp caustics, and detailed lens modeling reveals higher-order swallowtail caustic configurations. In the $z=2.91$ lens system, a small part of the source galaxy (which itself is part of a galaxy group) containing atleast two compact knots sits inside the swallowtail caustic, producing a quadruply imaged arc. At two of the image positions of these knots, we infer point source magnifications of $\gtrsim 300$, implying lensing-corrected effective radii of $\lesssim 0.8-1.5$ pc. The $z=6.70$ system exhibits even more complex image formation. We therefore only use the most confidently identified counter-images of knots in this system as constraints in our lens modeling. The resulting model predicts magnifications $\sim20-200$ and lensing-corrected effective radii of $\lesssim 0.8-18.5$ pc for various knots. Together, these two systems represent the first example of observations of multiple swallowtail image formations in a single galaxy cluster and demonstrate the ability of swallowtail caustics to magnify individual substructures at sub-parsec scales, from intermediate redshifts to the first billion years of the Universe. - oai:arXiv.org:2601.10097v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ashish K. Meena, Wenlei Chen, Lukas J. Furtak, Johan Richard, Adi Zitrin, Jose M. Diego, Mathilde Jauzac, Patrick L. Kelly, Rogier A. Windhorst - - - Using rapid rotators as tracers of multiplicity statistics as a function of stellar density - https://arxiv.org/abs/2601.10099 - arXiv:2601.10099v1 Announce Type: new -Abstract: Recent works have identified that rapidly rotating stars are predominantly binaries with separations of a few to a few tenths of au. This is a crucial range of separation that is often inaccessible to searches of binary stars, providing a unique opportunity to examine their statistical properties. In particular, we have performed an analysis of rapid rotators in young moving groups. We examined their fraction as a function of the stellar density of the population in which they are found. We find that there is a deficit of rapid rotators in dense clusters such as the Orion Nebula in comparison to the more diffuse parts of the Orion Complex, as intracluster interactions with neighboring stars likely dissolve binaries with intermediate separations before they had a chance to fully form. In contrast, in older populations with an age of $\sim100$ Myr, mass segregation redistributes binaries relative to single stars, thus in such older regions, rapid rotators are predominantly found in the regions of higher stellar density. This work sheds light on both the conditions that lead to the formation of binary stars and their dynamical evolution. - oai:arXiv.org:2601.10099v1 - astro-ph.SR - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 10.3847/1538-4357/ae2acd - Priyanka Cingirikonda, Marina Kounkel, Joseph Mullen - - - Direct Detection of Type II-P Supernova Progenitors with the Euclid and CSST Surveys - https://arxiv.org/abs/2601.10121 - arXiv:2601.10121v1 Announce Type: new -Abstract: A central goal in supernova (SN) research is to identify and characterize their progenitors. However, this is very difficult due to the limited archival images with sufficient depth and spatial resolution required for direct progenitor detection and due to the circumstellar dust which often biases the estimate of their intrinsic parameters. This field will be revolutionized by Euclid and the upcoming Chinese Space Station Survey Telescope (CSST), which conduct deep, wide-field, high-resolution and multi-band imaging surveys. We analyze their detection capability by comparing the model magnitudes of red supergiant (RSG) progenitors with the detection limits under different conditions, and we estimate the annual detection rates with Monte-Carlo simulations. We explore how to recover the intrinsic properties of SN progenitors with the help of radiation transfer calculations in circumstellar dust. We find the optical and near-infrared filters of the Euclid and CSST are highly effective for detecting RSG progenitors. We predict that archival images from the completed 2 surveys will enable $\lesssim13$ (or 24) progenitor detections per year within the mass range of 8--16 (or 8--25)M_\odot, an order of magnitude higher than the current detection rate of $\sim1$ detection per year. In the presence of circumstellar dust, the emerging spectral energy distribution (SED) of the progenitor is mainly affected by the optical depth and is almost independent of dust temperature in the Euclid and CSST filters. Our mock tests demonstrate that one can derive the progenitor mass and dust optical depth simultaneously by fitting the observed SED over the 11 filters of the 2 surveys while fixing the dust temperature to a typical value. Euclid and CSST will significantly enlarge the sample of direct progenitor detections with accurate mass measurements, which is crucial to resolve the long-standing RSG problem. - oai:arXiv.org:2601.10121v1 - astro-ph.SR - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Junjie Wu, Ning-Chen Sun, Zexi Niu, Tianmang Zhang, Chun Chen, Xiaohan Chen, Nancy Elias-Rosa, Morgan Fraser, Xinyi Hong, Justyn Maund, Cesar Rojas-Bravo, Anyu Wang, Beichuan Wang, Ziyang Wang, Qiang Xi, Linxi Zhang, Yinuo Zhang - - - The BINGO project X. Cosmological parameter constraints from HI Intensity Mapping lognormal simulations - https://arxiv.org/abs/2601.10152 - arXiv:2601.10152v1 Announce Type: new -Abstract: Building on the transformative success of optical redshift surveys, the emerging technique of neutral hydrogen (HI) intensity mapping (IM) offers a novel probe of large-scale structure (LSS) growth and the late-time accelerated expansion of the universe. - We present cosmological forecasts for the Baryon Acoustic Oscillations from Integrated Neutral Gas Observations (BINGO), a pioneering HI IM experiment, quantifying its potential to constrain the \textit{Planck}-calibrated $\Lambda$CDM cosmology and extensions to the $w_0w_a$CDM dark energy model. - For BINGO's Phase~1 configuration, we simulate the HI IM signal using a lognormal model and incorporate three dominant systematics: foreground residuals, thermal noise, and beam resolution effects. Using Bayesian inference, we derive joint constraints on six cosmological parameters ($\Omega_b h^2$, $\Omega_c h^2$, $100\theta_s$, $n_s$, $\ln 10^{10} A_s$, and $\tau_r$) alongside 60 HI parameters ($b_{\rm HI}^i$, $\Omega_{\rm HI}^i b_{\rm HI}^i$) across 30 frequency channels. - Our results demonstrate that combining BINGO with the Planck 2018 CMB dataset tightens the confidence regions of cosmological parameters to $\sim$40\% the size of those from Planck alone, significantly improving the precision of parameter estimation. Furthermore, BINGO constrains the redshift evolution of HI density and delivers competitive measurements of the dark energy equation of state parameters ($w_0$, $w_a$). - These results demonstrate BINGO's potential to extract significant cosmological information from the HI distribution and provide constraints competitive with current and future cosmological surveys. - oai:arXiv.org:2601.10152v1 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Pablo Motta, Camila P. Novaes, Elcio Abdalla, Jiajun Zhang, Gabriel A. Hoerning, Alessandro Marins, Eduardo J. de Mericia, Luiza O. Ponte, Amilcar R. Queiroz, Thyrso Villela, Bin Wang, Carlos A. Wuensche, Chang Feng, Edmar C. Gurj\~ao - - - A Highly Magnetic Ultra Massive White Dwarf with a 23-minute Rotation Period - https://arxiv.org/abs/2601.10188 - arXiv:2601.10188v1 Announce Type: new -Abstract: We present a physical characterization of TMTS J00063798+3104160 (J0006), a rapidly rotating,ultra-massive white dwarf (WD) identified in high-cadence light curves from the Tsinghua University-Ma Huateng Telescope for Survey (TMTS). A coherent 23-minute periodicity is detected in TMTS, TESS, and ZTF photometry. A time series of low-resolution spectra with the Keck-I 10 m telescope reveals broad, shallow hydrogen absorption features indicative of an extreme magnetic field and shows no evidence for radial-velocity variations. Atmospheric modeling yields a magnetic field strength of $\sim$ 250 MG, while Gaia astrometry and photometry imply a mass of 1.06 $\pm$ 0.01 M$_{\odot}$. A significant infrared excess is detected in the WISE W1 band and is well fitted by a 550 K blackbody, likely arising from residual material of a merger. We interpret the 23-minute photometric modulation as the rotation period of an isolated, massive WD formed likely through the merger of a double WD binary. With one of the shortest rotation periods known among candidate merger remnants and with constraints from a deep Einstein Probe X-ray nondetection, J0006 provides a rare and important observational window into the poorly explored intermediate stages of post-merger evolution. - oai:arXiv.org:2601.10188v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Jincheng Guo, Xiaofeng Wang, Qichun Liu, Alexei V. Filippenko, Thomas G. Brink, Jingkun Zhao, WeiKang Zhang, Yi Yang, Jie Lin, Haowei Peng, Hailiang Chen, Davron O. Mirzaqulov, Shuhrat A. Ehgamberdiev, Bin Ma, Jun Mo, Cheng Liu, Gaobo Xi, Xiaojun Jiang, Danfeng Xiang, Jicheng Zhang - - - Large-scale time-series spectroscopy for stellar ages - https://arxiv.org/abs/2601.10240 - arXiv:2601.10240v1 Announce Type: new -Abstract: To date, Galactic Astronomy has largely concerned itself with astrophysical processes, and with the locations, space motions and compositions of objects. Consider, for example, the elucidation of the components of the Galaxy over the past decades, its mapping as enabled by Gaia and its predecessors, the photometric and spectroscopic characterization of innumerable astrophysical objects in various wavelength ranges, both from the ground and from space, and the expanding discovery and characterization of exoplanets; all focused on the current, static Galaxy. This White Paper proposes a dedicated program to derive stellar ages from time-series spectroscopy to hasten the transformation of this static conception into a dynamical one with age-labeled objects and events. - oai:arXiv.org:2601.10240v1 - astro-ph.IM - astro-ph.GA - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - David Gruner, Sydney A. Barnes, Ansgar Reiners, Klaus G. Strassmeier, Cristina Chiappini, J\"org Weingrill, Michael Weber, Ilya Ilyin, Thomas Granzer, \"Ozg\"un Adebali, Jean-Michel D\'esert, Marica Valentini, Dario Fritzewski, Paolo Ventura, Alfio Bonanno, Jose-Dias do Nascimento, Jorge Melendez, Santosh Joshi, Yong-Cheol Kim - - - Cycle dependence of helioseismic oscillations above the acoustic cut-off frequency - https://arxiv.org/abs/2601.10283 - arXiv:2601.10283v1 Announce Type: new -Abstract: Helioseismic and recent asteroseismic observations reveal fine structure in the power spectrum with alternating peaks and troughs above the acoustic cut-off frequency. This structure is interpreted as the interference patterns of high-frequency acoustic waves excited in the solar interior and propagating into the atmosphere, known as pseudomodes. Pseudomodes exhibit clear solar-cycle variability, with frequency shifts that occur predominantly in anti-phase with the activity cycle, although the underlying mechanism remains uncertain. This work investigates how the subsurface excitation source location and the photospheric acoustic cut-off frequency influence the formation, frequency distribution, and solar-cycle variability of pseudomodes. We employ an analytical Klein-Gordon subsurface cavity model, which is shown to act as an effective Fabry-P\'erot interferometer for high-frequency waves that experience constructive and destructive interference between the source location and the lower turning point. We derive an effective dispersion relation isolating the effects of the source location and photospheric cut-off on the pseudomode frequency. The model reproduces the observed peak-trough pseudomode spectrum for reasonable parameter values constrained by Bayesian MCMC best-fitting to GONG observations. We also find that solar-cycle-associated 11-year modulations of the source location result in anti-phase pseudomode frequency shifts, whereas similar cyclic variations in the cut-off frequency produce harmonic-dependent behaviour, yielding both in-phase and anti-phase shifts. As the acoustic cut-off and mode excitation relate to stratification and flows in the solar interior, the results highlight pseudomodes as a powerful diagnostic tool for changes in subsurface solar and stellar structure through the solar cycle. - oai:arXiv.org:2601.10283v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Dmitrii Kolotkov, Anne-Marie Broomhall, Laura Jade Millson, Sergey Belov - - - How disc initial conditions sculpt the atmospheric composition of giant planets - https://arxiv.org/abs/2601.10285 - arXiv:2601.10285v1 Announce Type: new -Abstract: Past studies have revealed the dependency of the disc parameters (mass, radius, viscosity, grain fragmentation velocity, dust-to-gas ratio) on the formation of giant planets, where more massive discs seem beneficial for giant planet formation. It is unclear how the different disc properties influence the composition of forming giant planets. The idea that the atmospheric abundances can trace directly the formation location of planets is put into question, due to the chemical evolution of the disc, caused by inward drifting and evaporating pebbles. This complicates the idea of a relation between atmospheric abundances and planet formation locations. We use planet formation simulations that include the effects of pebble drift and evaporation and investigate how the different disc parameters influence the atmospheric composition of giant planets. We focus on the atmospheric C/O, C/H, O/H and S/H ratios allowing us to probe tracers for volatiles and refractories and thus different accretion pathways of giant planets. We find that most of the disc parameters have only a limited influence on the atmospheric abundances of gas giants, except for the dust-to-gas ratio, where a larger value results in higher atmospheric abundances. However the atmospheric abundances are determined by the planetary formation location, even in the pebble drift and evaporation scenario. Our study suggests that volatile-rich giant exoplanets predominantly form in the inner disc regions, where they can accrete large fractions of vapour-enhanced gas. Our study shows that simulations that try to trace the origin of giant planets via their atmospheric abundances do not have to probe all disc parameters, as long as the disc parameters allow the formation of giant planets. Our study thus suggests that the diversity of observed planetary compositions is a direct consequence of their formation location and migration history. - oai:arXiv.org:2601.10285v1 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Angie Daniela Guzm\'an Franco, Sofia Savvidou, Bertram Bitsch - - - Effect of Primordial Black Holes on the global 21-cm signal - https://arxiv.org/abs/2601.10304 - arXiv:2601.10304v1 Announce Type: new -Abstract: The 21-cm global signal, a treasure trove of information about the nature of the first luminous sources of the Universe, has traditionally been modelled assuming that these early sources were predominantly star-forming galaxies. However, recent observations by the James Webb Space Telescope (JWST) have revealed several AGNs as early as z ~ 10 - 10.4 . In light of this, it is important to investigate the contribution of such AGNs to the 21-cm signal. Assuming that these AGNs are seeded by Primordial Black Holes (PBHs) and employing an analytical PBH model, consistent with existing cosmological and astrophysical constraints, we show that these exotic objects can have a significant impact on the redshift evolution of the global signal. - oai:arXiv.org:2601.10304v1 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Atrideb Chatterjee - - - Extracting intrinsic alignments in the Dark Energy Survey's year 1 data, using the self-calibration method and LSST-DESC tools - https://arxiv.org/abs/2601.10314 - arXiv:2601.10314v1 Announce Type: new -Abstract: We present the implementation of a Self-Calibration of Intrinsic Alignments of galaxies as an extension to the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) Dark Energy Science Collaboration (DESC)'s weak lensing 3x2pt pipeline (TXPipe). As a demonstration, we have run this pipeline on the Dark Energy Survey (DES) year one data set. We find indications of a non-zero intrinsic alignment signal in the higher redshift bins, while in the lower bins our results look more uncertain. We believe this is caused by known issues with the individual galaxies photo-z estimation. This effect is particularly harmful for the self-calibration method, since it has high requirements for reliable estimation of the photo-$z$s, and the need for individual galaxy point estimates and tomographic binning to match. We show how different methods of recreating the redshift probability distribution can affect the detection of intrinsic alignment. - oai:arXiv.org:2601.10314v1 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Eske M. Pedersen (for the LSST Dark Energy Science Collaboration), Leonel Medina-Varela (for the LSST Dark Energy Science Collaboration), Emily Phillips Longley (for the LSST Dark Energy Science Collaboration), Mustapha Ishak (for the LSST Dark Energy Science Collaboration), Joe Zuntz (for the LSST Dark Energy Science Collaboration), Chihway Chang (for the LSST Dark Energy Science Collaboration), C. Danielle Leonard (for the LSST Dark Energy Science Collaboration) - - - Multimessenger Prospects for Low-Luminosity Gamma-Ray Bursts: Joint Neutrino and X-Ray Observations - https://arxiv.org/abs/2601.10317 - arXiv:2601.10317v1 Announce Type: new -Abstract: Low--luminosity gamma-ray bursts (LLGRBs) are promising candidates for high-energy neutrinos, yet no coincident neutrino events have been detected so far. Recent advances in X-ray time-domain astronomy, together with the development of next-generation neutrino telescopes, open new opportunities for joint X-ray and neutrino observations of these transients. We calculate the jet dynamical evolution and the associated neutrino production for both non-magnetized and magnetized outflows. For individual events, joint X-ray and neutrino detection is generally limited to nearby LLGRBs or sources with high luminosities. Thus, we consider a next-generation neutrino telescope with an effective area enhanced by a factor of $\sim30$ relative to IceCube. In the non-magnetized scenario, joint detection of individual events is enabled for sources with typical isotropic luminosities of $L_{\mathrm{iso}}\sim10^{47}\,\mathrm{erg\,s^{-1}}$ out to luminosity distances of $D_L\sim1.6\times10^{2}\,\mathrm{Mpc}$, corresponding to an expected detection rate of order $1$ per year. In contrast, for the magnetized scenario at the same luminosity, the accessible distance is significantly reduced, with joint observations confined to sources within $D_L\sim6.5\times10^{1}\,\mathrm{Mpc}$ and an expected detection rate of order $0.5$ per year. For stacked samples of $\sim100$ magnetized LLGRBs, stacking substantially enlarges the accessible distance range, enabling joint observations for sources with representative luminosities of $L_{\mathrm{iso}}\sim1\times10^{47}\,\mathrm{erg\,s^{-1}}$ out to $D_L\lesssim7.0\times10^{2}\,\mathrm{Mpc}$ and corresponding to an expected detection rate of order $2$ per year. These results demonstrate that joint X-ray and next-generation neutrino observations enable a practical multimessenger probe of LLGRBs. - oai:arXiv.org:2601.10317v1 - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Wenkang Lian, He Gao, Shunke Ai, B. Theodore Zhang - - - Testing the correlation between bending angle and polarization properties of bent radio galaxies - https://arxiv.org/abs/2601.10361 - arXiv:2601.10361v1 Announce Type: new -Abstract: The bending of radio galaxies in galaxy clusters is expected to be caused by interactions with the local environment. The physical processes responsible for jet bending, and their influence on the polarization properties of radio galaxies, remain poorly understood, leading to the question of whether jet properties in bent radio galaxies differ from those in linear radio galaxies. Using a sample of 24 polarized bent radio galaxies, observed with the Karl G. Jansky Very Large Array at 1--2 GHz, we test for correlation of bending angle with polarization parameters measuring Faraday rotation, intrinsic fractional polarization, and Faraday rotation dispersion, used here as a measure of turbulence along the line of sight. We find no statistically significant correlations. At the spatial resolution of our dataset (3--46 kpc, median 18.4 kpc), our results indicate that we are primarily probing larger-scale intracluster medium effects not related to bending angle. The absence of a statistically significant correlation suggests that bent radio galaxies are reliable probes of intracluster magnetic fields, because their intrinsic properties do not appear to introduce systematic biases into measured polarization parameters. We do detect a preference for source magnetic field vectors to align with the direction of jet bending. Finally, we estimate that the POSSUM and SKA surveys will contain $\gtrsim$300 and $\gtrsim$1000 polarized radio galaxies, respectively, providing large future samples with a range of bending angles and similar redshift distribution and number of beams per source as in our sample, enabling our results to be tested with greater statistical power. - oai:arXiv.org:2601.10361v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 10.3847/1538-4357/ae1cc9 - ApJ 996:81 (2026) - S. Vanderwoude, E. Osinga, B. M. Gaensler, J. L. West, R. J. van Weeren - - - Active Galactic Nuclei and STaR fOrmation in Nearby Galaxies (AGNSTRONG). II: Results for Jetted Type-I AGNs with Strong Ionized Gas Outflows - https://arxiv.org/abs/2601.10372 - arXiv:2601.10372v1 Announce Type: new -Abstract: We investigate the correlation between ionized gas outflows, jets, and star formation in a sample of 42 local type-I active galactic nuclei (AGNs) exhibiting significant [O III] outflows. This study uses both new submillimeter (sub-mm) observations and archival data from the James Clerk Maxwell Telescope. Our analysis, which includes a correction for jet emission in the sub-mm bands, fitting spectral energy distribution, and analyzing spectra, enables us to derive star-formation rates (SFRs) through various methods. By comparing radio power and SFRs, we select a sub-sample of jetted AGNs of which radio emission is mostly from the jets. We find that jetted AGNs predominantly lie above the main sequence of star-forming galaxies, suggesting a correlation between jet activity and star formation. By comparing dust extinction, we demonstrate that jetted AGNs do not have more dust which is the fuel of both star formation and AGN activity. Therefore, this correlation is more likely to arise from AGN feedback. We also find that the Eddington ratio does not impact the specific SFRs (sSFRs) of our sample. Additionally, for jetted AGNs, stronger radio emission corresponds to higher sSFRs, suggesting that jet emission may promote star formation, i.e., positive feedback. Our results not only shed light on the feedback mechanisms of AGNs but also underscore the complex interplay between black hole activity and star formation in galaxy evolution. - oai:arXiv.org:2601.10372v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Chen Qin, Huynh Anh N. Le, Yongquan Xue, Shifu Zhu, Xiaozhi Lin, Kim Ngan Nhat Nguyen - - - Long Period Transients (LPTs): a comprehensive review - https://arxiv.org/abs/2601.10393 - arXiv:2601.10393v1 Announce Type: new -Abstract: Long Period Transients (LPTs) are a recently identified class of sources characterized by periodic radio bursts lasting seconds to minutes, with flux densities that might reach several tens of Jy. These radio bursts repeat with periodicity from minutes to hours, and they exhibit strong polarization and transient activity periods. To date, about 12 such sources have been identified, which might encompass the same or different physical scenarios. Proposed explanations include binary systems with a white dwarf and a low-mass star companion, slow-spinning magnetars, highly magnetized isolated white dwarfs, and other exotic objects. In a few cases the optical counterpart indeed points toward a white dwarf with a low-mass companion, while in other cases, transient X-ray emission was detected, very common in magnetars. However, despite being able to reproduce partially some of the characteristics of LPTs, all the proposed scenarios find difficulty in explaining the exact physical origin of their bright, highly polarized and periodic radio emission. We review here the state-of-the-art in the observations and interpretation of this puzzling class of radio transients. - oai:arXiv.org:2601.10393v1 - astro-ph.HE - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Nanda Rea (ICE-CSIC, IEEC, Spain), Natasha Hurley-Walker (ICRAR, Curtin U., Australia), Manisha Caleb (University of Sydney, Australia) - - - Spectroscopic follow-up of Gaia alerted Young Stellar Object variables: the Large Binocular Telescope view - https://arxiv.org/abs/2601.10404 - arXiv:2601.10404v1 Announce Type: new -Abstract: We analyzed optical/near-IR Large Binocular Telescope spectra of 16 sources alerted by Gaia between 2021 and 2024 due to significant photometric variability. Half of the spectra were taken during quiescence and the rest during a burst or at intermediate brightness. Our analysis of their ten-year light curves and photometric/spectroscopic features provide evidence that all 16 sources are accreting Young Stellar Objects (YSOs). One object, Gaia23bab, is a known EXor source. Other light curves either have peaks over a stable baseline, or significant variability throughout the entire observation period, suggesting multiple contributing processes. All spectra exhibit emission lines from accretion columns, and over half of them show atomic forbidden lines as signatures of outflowing gas. We determined stellar parameters, accretion luminosity (Lacc) and mass accretion rate (Macc) at different brightness phases. Only two sources showed variability primarily due to extinction. During quiescence, our sources exhibit Lacc and Macc values typical of T Tauri and Herbig Ae/Be (HAEBE) sources, supporting the hypothesis that any YSO may undergo episodic accretion. In bursts, the Lacc and Macc of sources with photometric variations exceeding 2 mag follow a shallower relation with stellar luminosity and mass, typical of known EXor sources. This group includes one Class I, one flat-spectrum, and two Class II sources. Notably, the other Class I source, Gaia24beh, shows an Lacc value about ten times higher than typical EXor bursts of the same mass. In the other cases, Lacc and Macc align with variability seen in T Tauri and HAEBE sources. - oai:arXiv.org:2601.10404v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Teresa Giannini, Manuele Gangi, Fernando Cruz-Saenz de Miera, Brunella Nisini, Mate Szilagyi, Katia Biazzo, Agnes Kospal, Peter Abraham, Simone Antoniucci, Roberta Carini, Eleonora Fiorellino, Adriana Gargiulo, Ester Marini, Zsofia Nagy, Maria Gabriela Navarro, Fabrizio Vitali - - - ASTRA: A Python Package for Cross-Instrument Stellar and Telluric Template Construction - https://arxiv.org/abs/2601.10439 - arXiv:2601.10439v1 Announce Type: new -Abstract: ASTRA is a Python package that provides a modular, instrument-independent interface for working with high-resolution stellar spectra. Designed to support data from multiple spectrographs, including ESPRESSO (Pepe et al., 2021), HARPS (Mayor et al., 2003; Pepe et al., 2002), MAROON-X (Seifahrt et al., 2022), and CARMENES (Quirrenbach et al., 2014). ASTRA offers a unified abstraction over their data formats, enabling consistent access to fluxes, wavelengths, uncertainties, and metadata across instruments. Furthermore, it applies the necessary wavelength and flux calibrations that are needed, as described by the official pipelines of each instrument. - oai:arXiv.org:2601.10439v1 - astro-ph.IM - astro-ph.EP - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 10.21105/joss.09413 - Journal of Open Source Software, 11(117), 9413, 2026 - Andr\'e M. Silva, J. P. Faria, N. C. Santos, S. G. Sousa, P. T. P. Viana, J. H. C. Martins - - - TOI-3862 b: A dense super-Neptune deep in the hot Neptune desert - https://arxiv.org/abs/2601.10450 - arXiv:2601.10450v1 Announce Type: new -Abstract: The structure and evolution of close-in exoplanets are shaped by atmospheric loss and migration processes, which give rise to key population features such as the hot Neptune desert, ridge, and savanna - regions of the period-radius space whose boundaries offer critical insights into planetary formation and survival. As part of the KESPRINT collaboration, we selected the TESS transiting planet candidate TOI-3862.01 for radial velocity follow-up to confirm its planetary nature and characterize its mass and bulk properties. This planet candidate is of particular interest due to its position in the middle of the hot Neptune desert, making it a valuable probe for testing theories of planet migration and atmospheric loss. We confirmed the planetary nature and determined the mass of TOI-3862.01 (hereinafter TOI-3862b) by performing a joint fit with both transit and radial velocity data, precisely characterizing the bulk properties of this planet. TOI-3862b is a super-Neptune on a 1.56-day orbit around a Sun-like star with an effective temperature of 5300$\pm$50K. It has a mass of 53.7$_{-2.9}^{+2.8}$ M$_{\oplus}$ and a radius of 5.53$\pm$0.18 R$_{\oplus}$, corresponding to a density of 1.7$\pm$0.2 g/cm^3. This places it among the rare population of hot and dense super-Neptune desert planets. TOI-3862b, residing deep in the hot Neptune desert, represents a rare occurrence in an otherwise sparsely populated region, offering a valuable opportunity to probe the processes that may allow planets to survive in such environments. - oai:arXiv.org:2601.10450v1 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ilaria Carleo, Amadeo Castro-Gonz\'alez, Enric Pall\'e, Felipe Murgas, Grzegorz Nowak, Gaia Lacedelli, Thomas Masseron, Emily W. Wong, Patrick Eggenberger, Vincent Bourrier, Dawid Jankowski, Krzysztof Go\'zdziewski, Douglas R. Alves, James S. Jenkins, Sergio Messina, Keivan G. Stassun, Jose I. Vines, Matteo Brogi, David R. Ciardi, Catherine A. Clark, William Cochran, Karen A. Collins, Hans J. Deeg, Elise Furlan, Davide Gandolfi, Samuel Gerald\'ia Gonz\'alez, Artie P. Hatzes, Coel Hellier, Steve B. Howell, Judith Korth, Jorge Lillo-Box, John H. Livingston, Jaume Orell-Miquel, Carina M. Persson, Seth Redfield, Boris Safonov, David Baker, Rafael Delfin Barrena Delgado, Allyson Bieryla, Andrew Boyle, Pau Bosch-Cabot, N\'uria Casasayas Barris, Stavros Chairetas, Jerome P. de Leon, Izuru Fukuda, Akihiko Fukui, Pere Guerra, Kai Ikuta, Kiyoe Kawauchi, Emil Knudstrup, Florence Libotte, Michael B. Lund, Rafael Luque, Eduardo Lorenzo Mart\'in Guerrero de Escalante, Bob Massey, Edward J. Michaels, Giuseppe Morello, Norio Narita, Hannu Parvianien, Richard P. Schwarz, Avi Shporer, Monika Stangret, Noriharu Watanabe, Cristilyn N. Watkins - - - Alertissimo -- a tool for orchestration of LSST broker streams - https://arxiv.org/abs/2601.10454 - arXiv:2601.10454v1 Announce Type: new -Abstract: The Vera C. Rubin Observatory, through its Legacy Survey of Space and Time, will soon start producing 10 million alerts on transient astronomical objects per night. Due to logistics and bandwidth, alerts will not be dispatched directly to the public but to 'brokers' i.e. tools selected by LSST to handle alert streams. Brokers offer both common, specific and micro-specific functionalities related to alert handling, analysis, representation and dissemination. In this ecosystem, potentially augmented by data streams from other astronomical sources, there is a - need demonstrated by the community - for use cases which combine features of individual brokers. In this paper we present initial efforts and a prototype of such a tool, along with a language that would allow users to define use cases / workflows in a manner tailored for the domain. - oai:arXiv.org:2601.10454v1 - astro-ph.IM - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - V. Vujcic, V. A. Sreckovic, S. Babarogic - - - sponchpop II: Population Synthesis to Investigate Volatile Sulfur as a Fingerprint of Gas Giant Formation Histories - https://arxiv.org/abs/2601.10508 - arXiv:2601.10508v1 Announce Type: new -Abstract: Planet population synthesis is an integral tool for linking exoplanets to their formation environments. Most planet population synthesis studies have focused on the carbon-to-oxygen ratio (C/O) in gas or solids, yet more insight into planet formation may be afforded by considering a wider suite of elements. Sulfur is one such key element. It has been assumed to be entirely refractory in population synthesis models, restricting it to being a tracer of accreted rocky solids. However, sulfur also has a volatile reservoir dominant at the onset of star and planet formation. We investigate sulfur's wider potential as a formation history tracer by implementing the first multi-phase treatment of S in a planet population synthesis model. We present the planet formation module of \textsc{sponchpop} and its first predicted planet growth tracks and populations. We explore the diversity of planet compositions in terms of their sulfur budget, including both refractory and volatile components, and apply a novel gas-grain conversion of sulfur to study how formation trajectories of giant planets relate to final core and envelope compositions. We show that planets inherit a wide range of core and envelope sulfur content related to accretion history while considering late-stage planetesimal infall, providing a new diagnostic tool for planet formation. The diverse sulfur content of planet cores suggests some rocky planets may be born sulfur-poor, with implications for their geochemistry and habitability. Enhanced sulfur abundances in gas-giant atmospheres can be attributed to formation beyond the H2S iceline, such as the giants in our Solar System. - oai:arXiv.org:2601.10508v1 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Anna Sommerville-Thomas, Mihkel Kama, Oliver Shottle, Jason Ran - - - Discovery of the First Five Carbon-Enhanced Metal-Poor Stars in the LMC - https://arxiv.org/abs/2601.10514 - arXiv:2601.10514v1 Announce Type: new -Abstract: A substantial fraction of metal-poor stars in the local Milky Way halo exhibit large overabundances of carbon. These stars, dubbed Carbon-Enhanced Metal-Poor (CEMP) stars, provide crucial constraints on the nature of the early universe including the earliest nucleosynthetic events. Whether these stars exist at similar rates in nearby galaxies is a major open question with implications for the environmental dependence of early chemical evolution. Here, we present the discovery of the first five CEMP stars in the Milky Way's largest dwarf companion, the LMC, using SDSS-V spectra from the BOSS instrument. We measure metallicities ranging from [Fe/H] = -2.1 to -3.2 and evolutionary state corrected carbon enhancements of [C/Fe] = +1.2 to +2.4, placing these stars among the most metal-poor and carbon-rich ever identified in the LMC. This discovery demonstrates that CEMP stars do exist in the LMC despite previous null detections, and establishes the foundation for measuring the CEMP occurrence rate in this system. Such measurements will provide critical tests of whether environmental differences affect the formation channels and frequencies of these ancient, carbon-rich stars. - oai:arXiv.org:2601.10514v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Madeline Lucey, Vedant Chandra, Alexander Ji, Andrew Casey, David Nidever, Sean Morrison, Robyn Sanderson, Slater Oden, Jos\'e Fern\'andez-Trincado, Guilherme Limberg - - - Shock Signatures of the Successive Type-II Solar Radio Bursts at Meter Wavelength - https://arxiv.org/abs/2601.10528 - arXiv:2601.10528v1 Announce Type: new -Abstract: The successive type-II solar radio bursts observed on 31 July 2012 by the Bruny Island Radio Spectrometer (BIRS) in the frequency range between 62 - 6 MHz is reported and analyzed. The first type-II radio burst shows clear fundamental and harmonic band structures, while only one band is observed for the second type-II radio burst and is considered as the harmonic band. The first type-II radio burst is observed in the frequency range of 57 - 27 MHz between 00:03 - 00:09 UT at the harmonic band. The second type-II burst is observed between 00:18 - 00:27 UT in the frequency range of 43 - 17 MHz. The type-II radio bursts are associated with a C6 class flare located at the south-eastern limb (S24E87) and a CME observed from STEREO and LASCO observations. The EUVI signatures of the CME is observed in the ST-B EUVI FOV between 23:56 (on 30 July 2012) to 00:06 UT (on 31 July 2012), and are observed in the ST-B COR1 FOV between 00:10 - 00:35 UT moving within an average speed of 725 + or - 101 km/s. The CME is observed in the LASCO C2 FOV after 00:12 UT as a partial halo CME moving with an average speed of 486 km/s. The height-time plot shows that the first type-II radio burst was formed by the CME-shock along the shock front and the second type-II radio burst along the shock-dip structure, probably the dip structure results from the shock transiting across the high dense streamer structure. The successive type-II bursts are most likely produced by the single CME shock and their interactions with the streamer structures. The first type-II radio burst by the CME shock and the second type-II radio burst by the CME shock-streamer interactions. - oai:arXiv.org:2601.10528v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - V. Vasanth - - - Origins of the UV continuum and Balmer emission lines in Little Red Dots: observational validation of dense gas envelope models enshrouding the AGN - https://arxiv.org/abs/2601.10573 - arXiv:2601.10573v1 Announce Type: new -Abstract: We present a statistical study on the origins of the UV continuum and narrow/broad emission lines in little red dots (LRDs), a newly discovered class of active galactic nuclei (AGNs). Leveraging all archived JWST/NIRSpec data, we build a sample of 28 spectroscopically-confirmed LRDs at $5<z_{\rm spec}<7.2$, by requiring broad H$\alpha$ emission, blue UV colors, V-shaped continua, and compact morphologies. We define a control sample of 9 blue, compact, broad-line AGNs without red optical continua (hereafter little blue dots; LBDs), and examine correlations between rest UV and the narrow/broad H$\alpha$ luminosities in these populations. In LRDs, both narrow and broad H$\alpha$ components are tightly correlated with the UV continuum, and the luminosity ratios are consistent with those in young starburst galaxies. In contrast, the UV to broad H$\alpha$ ratios in LBDs closely match local unobscured AGNs and are statistically different from LRDs. The Ly$\alpha$ occurrence rates and strengths do not differ between LRDs and LBDs and are comparable to normal star-forming galaxies. These results are consistent with a scenario where the central BH in LRDs is enshrouded by a dense opaque gas envelope -- in this model, the UV continuum as well as narrow and even broad H$\alpha$ emissions are not powered by AGNs but predominantly by young massive stars surrounding the envelope, while the envelope radiates as a $\sim 5000$ K blackbody. As the envelope dissipates, direct AGN emission can emerge, potentially transforming LRDs into LBDs and marking the end of a short-lived phase of rapid black hole growth. - oai:arXiv.org:2601.10573v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yoshihisa Asada, Kohei Inayoshi, Qinyue Fei, Seiji Fujimoto, Chris Willott - - - HST Observations of HD 166620 and Tau Ceti: First UV Spectra of a Magnetic Grand Minimum Star and the Extent of Tau Ceti's Astrosphere - https://arxiv.org/abs/2601.10579 - arXiv:2601.10579v1 Announce Type: new -Abstract: We present new Hubble Space Telescope (HST) UV spectra of the K2 V star HD 166620, the first star clearly recognized to be in a "magnetic grand minimum" state analogous to the Sun's "Maunder Minimum" in the late 1600's. The stellar H I Lyman-alpha surface fluxes are extremely low, about a factor of two below fluxes observed during solar minimum, and also significantly lower than those of Tau Ceti (G8 V) and HD 191408 (K2.5 V), two stars more similar to HD 166620 in spectral type and age (~10 Gyr) than the Sun. The Tau Ceti data that are compared with HD 166620 include both old archival data and a new HST observation as well. The Lyman alpha data are used to confirm a nondetection of astrospheric Lyman-alpha absorption for this star, suggesting a very weak wind with Mdot<0.1 Mdot_sun. The very compact astrosphere inferred for Tau Ceti indicates that the star's debris disk is at least partly exposed to the ISM, and we discuss possible consequences. - oai:arXiv.org:2601.10579v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Brian E. Wood, Hans-Reinhard Mueller, Dean Hartshorn, Seth Redfield, Travis S. Metcalfe - - - Canceling Effects of Conjunctions Render Higher Order Mean Motion Resonances Weak - https://arxiv.org/abs/2601.10585 - arXiv:2601.10585v1 Announce Type: new -Abstract: Mean motion resonances (MMRs) are a key phenomenon in orbital dynamics. The traditional disturbing function expansion in celestial mechanics shows that, at low eccentricities, $p$:$p-q$ MMRs exhibit a clear hierarchy of strengths, scaling as $e^q$, where $q$ is the order of the resonance. This explains why first-order MMRs (e.g., 3:2 and 4:3) are important, while the infinite number of higher order integer ratios are not. However, this relationship derived from a technical perturbation series expansion provides little physical intuition. In this paper, we provide a simple physical explanation of this result for closely spaced orbits. In this limit, interplanetary interactions are negligible except during close encounters at conjunction, where the planets impart a gravitational "kick" to each other's mean motion. We show that while first-order MMRs involve a single conjunction before the configuration repeats, higher order MMRs involve multiple conjunctions per cycle, whose effects cancel out more precisely the higher the order of the resonance. Starting from the effects of a single conjunction, we provide an alternate, physically motivated derivation of MMRs' $e^q$ strength scaling. - oai:arXiv.org:2601.10585v1 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Elizabeth K Jones, Samuel Hadden, Daniel Tamayo - - - High-fidelity stellar extinction with Gaia and APOGEE -- I. The method and a new extinction curve - https://arxiv.org/abs/2601.10595 - arXiv:2601.10595v1 Announce Type: new -Abstract: The scarcity of high-fidelity extinction measurements remains a bottleneck in deriving accurate stellar properties from Gaia parallaxes. In this work, we aim to derive precision extinction estimates for APOGEE DR19 stars, establishing a new benchmark for Galactic stellar population studies. We first determine reddening by comparing observed colorsr, etrieved from photometric surveys or standardized synthetic magnitudes from Gaia BP/RP spectra, to intrinsic colors predicted via an XGBoost model. The model is trained on minimally reddened stars to infer intrinsic colors and their associated uncertainties, using APOGEE stellar parameters (Teff, logg, [Fe/H], and [alpha/Fe]). The derived reddening values are then converted into extinctions using an anchor ratio of A_BP / A_RP = 1.694 +/- 0.004, derived from red-clump-like stars. Here, we provide extinction measurements in 39 filters across 10 photometric systems and introduce a new empirical extinction curve optimized for broadband passbands. Our extinction estimates (Av) outperform existing results (Bayestar19, StarHorse, SEDEX), achieving a typical precision of 0.03 mag in Av. Notably, we identify systematic deviations of up to 30% between monochromatic and passband-integrated extinction ratios at wavelengths greater than 700 nm. This result highlights the necessity of adopting passband-specific coefficients when correcting extinction to derive stellar parameters. As the foundation for a forthcoming series of papers, these benchmark measurements will be used to (1) revise asteroseismic scaling relations, (2) calibrate differential reddening in open clusters, and (3) reconcile heterogeneous dust maps into a unified, all-sky extinction scheme. - oai:arXiv.org:2601.10595v1 - astro-ph.SR - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jie Yu, Luca Casagrande, John A. Taylor, Ioana Ciuc\u{a}, Giacomo Cordoni, Ronald Drimmel, Shourya Khanna, Hiep Nguyen, Tomasz R\'o\.za\'nski, Dennis Stello, Haibo Yuan, Zhen Yuan - - - A young progenitor for the most common planetary systems in the Galaxy - https://arxiv.org/abs/2601.10598 - arXiv:2601.10598v1 Announce Type: new -Abstract: The Galaxy's most common known planetary systems have several Earth-to-Neptune-size planets in compact orbits. At small orbital separations, larger planets are less common than their smaller counterparts by an order of magnitude. The young star V1298 Tau hosts one such compact planetary system, albeit with four planets that are uncommonly large (5 to 10 Earth radii). The planets form a chain of near-resonances that result in transit-timing variations of several hours. Here we present a multi-year campaign to characterize this system with transit-timing variations, a method insensitive to the intense magnetic activity of the star. Through targeted observations, we first resolved the previously unknown orbital period of the outermost planet. The full 9-year baseline from these and archival data then enabled robust determination of the masses and orbital parameters for all four planets. We find the planets have low, sub-Neptune masses and nearly circular orbits, implying a dynamically tranquil history. Their low masses and large radii indicate that the inner planets underwent a period of rapid cooling immediately after dispersal of the protoplanetary disk. Still, they are much less dense than mature planets of comparable size. We predict the planets will contract to 1.5-4.0 Earth radii and join the population of super-Earths and sub-Neptunes that nature produces in abundance. - oai:arXiv.org:2601.10598v1 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 10.1038/s41586-025-09840-z - Nature 649, 310-314 (2026) - John H. Livingston, Erik A. Petigura, Trevor J. David, Kento Masuda, James Owen, David Nesvorn\'y, Konstantin Batygin, Jerome de Leon, Mayuko Mori, Kai Ikuta, Akihiko Fukui, Noriharu Watanabe, Jaume Orell Miquel, Felipe Murgas, Hannu Parviainen, Judith Korth, Florence Libotte, N\'estor Abreu Garc\'ia, Pedro Pablo Meni Gallardo, Norio Narita, Enric Pall\'e, Motohide Tamura, Atsunori Yonehara, Andrew Ridden-Harper, Allyson Bieryla, Alessandro A. Trani, Eric E. Mamajek, David R. Ciardi, Varoujan Gorjian, Lynne A. Hillenbrand, Luisa M. Rebull, Elisabeth R. Newton, Andrew W. Mann, Andrew Vanderburg, Gu{\dh}mundur Stef\'ansson, Suvrath Mahadevan, Caleb Ca\~nas, Joe Ninan, Jesus Higuera, Kamen Todorov, Jean-Michel D\'esert, Lorenzo Pino - - - On the Physical Origins of the Millimeter Fundamental Plane in Active Galactic Nuclei - https://arxiv.org/abs/2601.10612 - arXiv:2601.10612v1 Announce Type: new -Abstract: Observations of active galactic nuclei have revealed a correlation between millimeter luminosity, X-ray luminosity, and mass, suggesting the emission in each of these bands is powered by a common source. Starting with a set of five general relativistic magnetohydrodynamic simulations with dynamically important magnetic fields, we perform ray-tracing calculations to produce spectra including synchrotron emission, bremsstrahlung emission, and Compton scattering. Our models with similar Eddington ratios to the objects for which the relationship was inferred naturally reproduce observations without tuning. Our lower Eddington ratio models depart from this relationship, likely attributable to an observational bias against extremely low accretion rates. We find that inverse Compton scattering dominates the production of X-rays over bremsstrahlung radiation in almost all models, and in all models consistent with the observed correlation. We find only a modest spin dependence in this relationship. This study demonstrates that a compact, hot accretion flow with dynamically important magnetic fields can naturally explain observed millimeter and X-ray properties in low-luminosity active galactic nuclei. Future work should explore the impacts of non-thermal electron populations, weaker magnetic fields, and radiative cooling. - oai:arXiv.org:2601.10612v1 - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Kratika Mazde, Angelo Ricarte, George N. Wong - - - Circumplanetary Disk Candidate in the Disk of HD 163296 Traced by Localized Emission from Simple Organics - https://arxiv.org/abs/2601.10631 - arXiv:2601.10631v1 Announce Type: new -Abstract: Atacama Large Millimeter/submillimeter Array observations suggest that the disc of HD 163296 is being actively shaped by embedded, yet unseen protoplanets, as indicated by numerous gas and dust substructures consistent with planet-disc interaction models. We report the first detection of simple organic molecules, HCN and C2H, tracing a candidate circumplanetary disc (CPD) in the HD 163296 system, located at an orbital radius of $R=88\pm7$ au and azimuth $\phi=46\pm3^\circ$ (or $R=0.75''$, $\rm{{PA}}=350^\circ$ in projected sky coordinates), and originating near the midplane of the circumstellar disc. The signature is localised but spectrally resolved, and it overlaps with a previously reported planet candidate, P94, identified through kinematic perturbations traced by CO lines. We propose a scenario in which the observed chemical anomalies arise from increased heating driven by the forming planet and ongoing accretion through its CPD, facilitating the thermal desorption of species that would otherwise remain frozen out in the disc midplane, and potentially triggering the activation barriers of chemical reactions that lead to enhanced molecular production. Based on a first-order dynamical analysis of the HCN spectrum from the CPD--isolated with a 7$\sigma$ significance--we infer an upper limit on the planet mass of 1.8 $M_{\rm Jup}$, consistent with predictions from CO kinematics and constraints from direct imaging studies. By comparing the CPD sizes derived from our models with theoretical expectations where the CPD radius corresponds to roughly one-third of the planet's Hill radius, we favor CPD gas temperatures $T > 150$ K, planet masses $M_{\rm p} < 1.0$ $M_{\rm Jup}$, and CPD radii $R_{\rm CPD} < 2$ au. - oai:arXiv.org:2601.10631v1 - astro-ph.EP - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 10.3847/2041-8213/ae2f59 - Andres F. Izquierdo, Jaehan Bae, Maria Galloway-Sprietsma, Ewine F. van Dishoeck, Stefano Facchini, Giovanni Rosotti, Jochen Stadler, Myriam Benisty, Leonardo Testi - - - WEAVE imaging spectroscopy of NGC 6720: an iron bar in the Ring - https://arxiv.org/abs/2601.10635 - arXiv:2601.10635v1 Announce Type: new -Abstract: We present spatially resolved spectroscopic observations of the planetary nebula NGC 6720, the Ring Nebula, taken during the science verification phase of WEAVE, a new instrument mounted on the William Herschel Telescope on La Palma. We use the instrument's Large Integral Field Unit (LIFU) to obtain spectra of the Ring Nebula, covering its entire optically bright inner regions as well as parts of its much fainter outer molecular halo. We report the discovery of emission from [Fe~{\sc v}] and [Fe~{\sc vi}] confined to a narrow ``bar'' extending across the central regions of the nebula. No lines of other elements share this morphology or, at the spectral resolving power used ($R \sim 2500$), the same radial velocity. The extent to which iron in this bar is depleted is presently unclear; comparison with JWST-detected dust continuum emission suggests that some dust grain destruction may be occurring in the region, but there is currently no observational evidence for the $>$ 50~km\,s$^{-1}$ shock waves or $T > 10^6$~K X-ray emitting gas needed to enable this. Where the bar is located along the line of sight through the nebula, and how it was created, are new puzzles to be solved for this iconic planetary nebula. - oai:arXiv.org:2601.10635v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1093/mnras/staf2139 - R. Wesson, J. E. Drew, M. J. Barlow, J. Garc\'ia-Rojas, R. Greimel, D. Jones, A. Manchado, R. A. H. Morris, A. Zijlstra, P. J. Storey, J. A. L. Aguerri, S. R. Berlanas, E. Carrasco, G. B. Dalton, E. Gafton, R. Garc\'ia-Benito, A. L. Gonz\'alez-Mor\'an, B. G\"ansicke, S. Hughes, S. Jin, R. Raddi, R. Sanchez-Janssen, E. Schallig, D. J. B. Smith, S. C. Trager, N. A. Walton - - - Measuring the Coronal Magnetic Field with 2D Coronal Seismology: A Forward-Modeling Validation - https://arxiv.org/abs/2601.10637 - arXiv:2601.10637v1 Announce Type: new -Abstract: In recent years, a two-dimensional (2D) coronal seismology technique applied to spectral-imaging data from the Coronal Multi-channel Polarimeter (CoMP) and UCoMP has enabled routine measurement of the global coronal magnetic field. The technique combines coronal transverse wave phase speed from Doppler measurements with electron densities from the Fe \sc{xiii}\rm{} 10798/10747 \AA\ intensity ratio to infer the magnetic field strength, while the wave propagation directions from Doppler measurements trace the magnetic field direction. To validate the accuracy and robustness of this method, we use forward modeling of a MURaM simulation that produces open and closed magnetic structures with excited waves. From the synthetic Doppler velocity, Fe \sc{xiii}\rm{} infrared line intensities, and linear polarization signals, we apply the 2D coronal seismology technique to estimate the magnetic field strength and direction. A comparison with the simulation ground truth shows close agreement, indicating that the technique can recover the line-of-sight emissivity-weighted magnetic field direction and strength with high accuracy. We also perform a parameter-space analysis to quantify sensitivities of the method to parameter choice. These findings provide practical guidance for CoMP/UCoMP-like analysis and demonstrate that 2D coronal seismology can deliver reliable, LOS emissivity-weighted measurements of the coronal magnetic field from coronal wave observations. - oai:arXiv.org:2601.10637v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Zihao Yang, Sarah Gibson, Matthias Rempel, Giuliana de Toma - - - Cosmoglobe DR2. VI. Disentangling hot and cold thermal dust emission with Planck HFI - https://arxiv.org/abs/2601.10640 - arXiv:2601.10640v1 Announce Type: new -Abstract: We present a four-component high-resolution model of thermal dust emission for microwave and sub-mm frequencies derived from Planck HFI, WHAM and Gaia. The resulting high-resolution model derived here forms the basis for the thermal dust model employed in the Cosmoglobe DR2 reanalysis of COBE-DIRBE. The four dust components are called ``cold dust'', ``hot dust'', ``nearby dust'', and ``Ha correlated dust'', respectively, and trace different physical environments. The spatial distributions of the nearby dust and Ha dust components are defined by the Edenhofer et al. Gaia 3D extinction model and the WHAM survey, respectively, while the hot and cold dust components are fit freely pixel-by-pixel to the Planck HFI data. We use a global parameter grid search coupled to an amplitude map Gibbs sampler to fit this model to Planck HFI data. In agreement with the companion low-resolution analysis, we find that the hot dust component is strongly correlated with the FIRAS Cii map, while the cold dust component is strongly correlated with the HI4PI Hi map. Despite its fewer degrees of freedom per pixel compared to the Planck 2015 legacy dust model, we find that this new model performs competitively in terms of overall residuals, capturing over 98% of the full-sky dust variance for all channels. When fitting a spatially varying 3-parameter MBB model to the new dust model with isotropic SEDs, we find very similar spatial distributions to those of the official Planck analysis, and this new model thus represents an economical decomposition of previously published spatially varying spectral parameter maps. We conclude that this new model represents both a statistically more efficient summary of thermal dust in the microwave and far-infrared regimes and a physically more realistic decomposition of the sky compared to the traditional 3-parameter MBB model. (abridged) - oai:arXiv.org:2601.10640v1 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - R. M. Sullivan, E. Gjerl{\o}w, M. Galloway, D. J. Watts, R. Aurvik, A. Basyrov, L. A. Bianchi, A. Bonato, M. Brilenkov, H. K. Eriksen, U. Fuskeland, K. A. Glasscock, L. T. Hergt, D. Herman, J. G. S. Lunde, A. I. Silva Martins, M. San, D. Sponseller, N. -O. Stutzer, H. Thommesen, V. Vikenes, I. K. Wehus, L. Zapelli - - - HII regions in NGC 628: the view of two catalogs - https://arxiv.org/abs/2601.10642 - arXiv:2601.10642v1 Announce Type: new -Abstract: The study is devoted to comparing the parameters of the interstellar medium of HII regions in the Kongiu and Groves catalogs for the galaxy NGC 628. The article analyzes the characteristics of star-forming regions, including a comparison of radiation fluxes in the ranges of 7.7 $\mu$m and 21 $\mu$m and in the H$\alpha$, H$\beta$, OIII and CO lines, calculating the kinematic parameters (FWHM) for the lines, and analyzing the spatial distribution of regions for both catalogs. - The results of the study showed that the regions from the Groves catalog demonstrate higher line widths compared to the Kongiu catalog. Signs of possible misidentified classification of some regions from the Groves catalog were revealed: there is a possibility that some of them are not HII regions, but shock ionization regions. - oai:arXiv.org:2601.10642v1 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Ksenia I. Smirnova, Dmitri S. Wiebe - - - Observation Timelines for the Potential Lunar Impact of Asteroid 2024 YR4 - https://arxiv.org/abs/2601.10666 - arXiv:2601.10666v1 Announce Type: new -Abstract: The near-Earth asteroid 2024 YR4 -- a $\sim$60 m rocky object that was once considered a potential Earth impactor -- has since been ruled out for Earth but retained a $\sim$4.3% probability of striking the Moon in 2032. Such an impact, with equivalent kinetic energy of $\sim$6.5 Mt TNT, is expected to produce a $\sim$1 km crater on the Moon, and will be the most energetic lunar impact event ever recorded in human history. Despite the associated risk, this scenario offers a rare and valuable scientific opportunity. Using a hybrid framework combining Monte Carlo orbital propagation, smoothed particle hydrodynamics (SPH) impact modeling, and N-body ejecta dynamics, we evaluate the physical outcomes and propose the observation timelines of this rare event. Our results suggest an optical flash of visual magnitude from -2.5 to -3 lasting several minutes directly after the impact, followed by hours of infrared afterglow from $\sim$2000 K molten rock cooling to a few hundred K. The associated seismic energy release would lead to a global-scale lunar reverberation (magnitude $\sim$5.0) that can be detectable by modern seismometers. Furthermore, the impact would eject $\sim$10$^8$ kg of debris that escapes the lunar gravity, with a small fraction reaching Earth to produce a lunar meteor outburst within 100 years. Finally, we integrate these results into a coordinated observation timeline, identifying the best detection windows for ground-based telescopes, lunar orbiters, and surface stations. - oai:arXiv.org:2601.10666v1 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yifan He, Yixuan Wu, Yifei Jiao, Wen-Yue Dai, Xin Liu, Bin Cheng, Hexi Baoyin - - - MHD modelling of open flux evolution around solar maximum by coronal model COCONUT - https://arxiv.org/abs/2601.10675 - arXiv:2601.10675v1 Announce Type: new -Abstract: To evaluate impact of temporal evolution and commonly used harmonic filtering of magnetograms, and the empirically defined oversimplified heating source terms on open-field distributions, we use a series of hourly-updated magnetograms, preprocessed by the 10th- and 50th-order filtered PF solvers, to drive COCONUT, configured with different heating prescriptions, to mimic coronal evolutions during CRs 2282 and 2283. We evaluate the simulated open magnetic flux at 1.01~$R_s$, 3~$R_s$, and 0.1~AU, and compare them with interplanetary observations. The results show that the simulated unsigned open flux evaluated near the solar surface can be comparable to that derived from interplanetary in situ observations. However, in low corona, numerous small-scale closed-field magnetic structures introduce magnetic polarity inversion interfaces within the open field, cancelling part of the open field near these interfaces during the volume-integration procedure of the finite-volume method. Consequently, the simulated unsigned open flux can be reduced by up to 45% at 0.1~AU and decreases more rapidly in the low corona. The results also indicate that moderate adjustments to the heating source term can effectively regulate the magnitude of the unsigned open magnetic flux. Preprocessing the initial magnetogram by a PF solver with limited spherical harmonics can reduce the open flux in the low corona and alter the distribution of open-field regions, but has little effect on the total unsigned open flux at larger heliocentric distances. The ratio of the maximum to minimum open unsigned magnetic flux can reach 1.4 within a single solar maximum CR. These findings highlight the necessity of considering finer grid resolution around magnetic polarity inversion interfaces, more realistic heating mechanisms, and the time-evolving regime of MHD coronal modelling when further addressing the ``open flux problem". - oai:arXiv.org:2601.10675v1 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Haopeng Wang, Stefaan Poedts, Andrea Lani, Luis Linan, Tinatin Baratashvili, Hyun-Jin Jeong, Rayan Dhib, Quentin Noraz, Wenwen Wei, Mahdi Najafi-Ziyazi, Junyan Liu, Hao Wu, Rui Zhuo, Jos\'e Miguel Luzia Murteira, Ketevan Arabuli, Brigitte Schmieder, Jasmina Magdaleni\'c Zhukov - - - Late-time acceleration without a vacuum term in ${f(R,L_m)}$ gravity: scaling deSitter dynamics and parameter constraints - https://arxiv.org/abs/2601.10699 - arXiv:2601.10699v1 Announce Type: new -Abstract: We investigate late-time cosmic acceleration in $f(R,L_m)$ gravity driven by nonlinear matter contributions, focusing on the class $f(R,L_m)=R/2+c_1 L_m+c_n L_m^{n}+c_0$ with the explicit choice $L_m=\rho_m$ and an uncoupled radiation sector. We analyze two realizations: (i) Case A: $f(R,L_m)=R/2+\beta \rho_m^{n}+\gamma$, where $\gamma$ acts as a vacuum term, and (ii) Case B: $f(R,L_m)=R/2+\beta \rho_m+\gamma \rho_m^{n}$, where the nonlinear sector can mimic dark energy without an explicit cosmological constant. For each case, we construct a bounded autonomous system, classify all critical points and their stability, and compute cosmographic diagnostics. The phase-space analysis shows that Case A reproduces the standard radiation$\to$matter$\to$de~Sitter sequence only for $n\gtrsim 4/5$, with acceleration essentially enforced by the vacuum term. In contrast, Case~B admits a qualitatively distinct and phenomenologically appealing branch: for $0<n<1/2$ the system possesses a physical \emph{scaling} de~Sitter future attractor inside the bounded simplex, yielding radiation$\to$matter$\to$acceleration with $q=-1$ and $\omega_{\rm eff}=-1$ and without introducing $c_0$. We confront both models with background data (CC, Union3, DESI BAO, plus a BBN prior on $\Omega_b h^2$) using nested sampling and perform model comparison via Bayesian evidence and AIC/BIC. The full data combination constrains $n=1.08\pm0.05$ in Case A and $n=0.05\pm0.10$ in Case B (68\% CL), the latter lying within the accelerating window while remaining statistically consistent with $\Lambda$CDM kinematics at the background level. We also record minimal consistency conditions for stability (tensor no-ghost and luminal propagation) and motivate a dedicated perturbation-level analysis as the next step to test growth and lensing observables. - oai:arXiv.org:2601.10699v1 - astro-ph.CO - gr-qc - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Luciano Navarro-Coyd\'an, J. Alberto V\'azquez, Israel Quiros, Ricardo Garc\'ia-Salcedo - - - Euclid preparation. 3D reconstruction of the cosmic web with simulated Euclid Deep spectroscopic samples - https://arxiv.org/abs/2601.10709 - arXiv:2601.10709v1 Announce Type: new -Abstract: The ongoing Euclid mission aims to measure spectroscopic redshifts for approximately two million galaxies using the H $\alpha$ line emission detected in near-infrared slitless spectroscopic data from the Euclid Deep Fields (EDFs). These measurements will reach a flux limit of $5\times 10^{-17}\,{\rm erg}\,{\rm cm}^{-2}\,{\rm s}^{-1}$ in the redshift range $0.4<z<1.8$, opening the door to numerous investigations involving galaxy evolution, extending well beyond the mission's core objectives. The achieved H $\alpha$ luminosity depth will lead to a sufficiently high sampling, enabling the reconstruction of the large-scale galaxy environment. We assess the quality of the reconstruction of the galaxy cosmic web environment with the expected spectroscopic dataset in EDFs. The analysis is carried out on the Flagship and GAEA galaxy mock catalogues. The quality of the reconstruction is first evaluated using geometrical and topological statistics measured on the cosmic web, namely the length of filaments, the area of walls, the volume of voids, and its connectivity and multiplicity. We then quantify how accurately gradients in galaxy properties with distance from filaments can be recovered. As expected, the small-scale redshift-space distortions, have a strong impact on filament lengths and connectivity, but can be mitigated by compressing galaxy groups before skeleton extraction. The cosmic web reconstruction is biased when relying solely on H $\alpha$ emitters. This limitation can be mitigated by applying stellar mass weighting during the reconstruction. However, this approach introduces non-trivial biases that need to be accounted for when comparing to theoretical predictions. Redshift uncertainties pose the greatest challenge in recovering the expected dependence of galaxy properties, though the well-established stellar mass transverse gradients towards filaments can still be observed. - oai:arXiv.org:2601.10709v1 - astro-ph.GA - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Euclid Collaboration, K. Kraljic (Universit\'e de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France), C. Laigle (Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, France), M. Balogh (Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada), P. Jablonka (Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique F\'ed\'erale de Lausanne), U. Kuchner (School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK), N. Malavasi (Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany), F. Sarron (Institut de Recherche en Informatique de Toulouse, Laboratoire MCD, Centre de Biologie Int\'egrative), C. Pichon (Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, France, Kyung Hee University, Dept. of Astronomy \& Space Science, Yongin-shi, Gyeonggi-do 17104, Republic of Korea), G. De Lucia (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), M. Bethermin (Universit\'e de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France), F. Durret (Institut d'Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France), M. Fumagalli (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, Dipartimento di Fisica "G. Occhialini", Universit\`a degli Studi di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy), C. Gouin (Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, France), M. Magliocchetti (INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy), 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), O. Cucciati (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), 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), M. Hirschmann (Institute of Physics, Laboratory for Galaxy Evolution, Ecole Polytechnique F\'ed\'erale de Lausanne, Observatoire de Sauverny, CH-1290 Versoix, Switzerland), Y. Kang (Department of Astronomy, University of Geneva, ch. d'Ecogia 16, 1290 Versoix, Switzerland), M. Spinelli (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, INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy, Department of Physics and Astronomy, University of the Western Cape, Bellville, Cape Town, 7535, South Africa), N. Aghanim (Universit\'e Paris-Saclay, CNRS, Institut d'astrophysique spatiale, 91405, Orsay, France), 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), S. Bardelli (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, 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), R. Casas (Institut d'Estudis Espacials de Catalunya, Institute of Space Sciences), S. Casas (Institute for Theoretical Particle Physics and Cosmology), F. J. Castander (Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya), 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), 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), S. de la Torre (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France), 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), C. A. J. Duncan (Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK, Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, 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. 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), 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 (Universit\"ats-Sternwarte M\"unchen, Fakult\"at f\"ur Physik, Ludwig-Maximilians-Universit\"at M\"unchen, Scheinerstr. 1, 81679 M\"unchen, 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), S. V. H. Haugan (Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, 0315 Oslo, Norway), 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), 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), M. Kilbinger (Universit\'e Paris-Saclay, Universit\'e Paris Cit\'e, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France), 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), 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), 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), 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, 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 (Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada), 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), 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), C. Rosset (Universit\'e Paris Cit\'e, CNRS, Astroparticule et Cosmologie, 75013 Paris, France), 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), 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), 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, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, 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), 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), 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 (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, 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 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, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, 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), V. Allevato (INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, 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), M. Bolzonella (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), 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 Emilio Bianchi 46, 23807 Merate, Italy, 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), I. Risso (INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy, and 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), A. Balaguera-Antolinez (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), P. Bergamini (Dipartimento di Fisica "Aldo Pontremoli", Universit\`a degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy, INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, 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), 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), 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), 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, Institut d'Estudis Espacials de Catalunya, Institute of Space Sciences), 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), R. Chary (Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA, University of California, Los Angeles, CA 90095-1562, USA), 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), T. Contini (Institut de Recherche en Astrophysique et Plan\'etologie), 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), 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), 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), A. Fontana (INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, 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 Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), R. Gavazzi (Aix-Marseille Universit\'e, CNRS, CNES, LAM, Marseille, France, Institut d'Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Universit\'e, 98 bis boulevard Arago, 75014 Paris, 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. 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), S. Joudaki (Centro de Investigaciones Energ\'eticas, Medioambientales y Tecnol\'ogicas), J. J. E. Kajava (Department of Physics and Astronomy, Vesilinnantie 5, University of Turku, 20014 Turku, Finland, Serco for European Space Agency), 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), 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), M. Lattanzi (Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, 44122 Ferrara, Italy), 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), 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), L. Leuzzi (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, 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), G. Maggio (INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy), E. A. Magnier (Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA), 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), 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), 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), 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), 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), 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), 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 (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), 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), 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), 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, 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), D. Vergani (INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy), 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), N. A. Walton (Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK) - - - When spacetime vibrates: An introduction to gravitational waves - https://arxiv.org/abs/2512.22679 - arXiv:2512.22679v1 Announce Type: cross -Abstract: This article presents a comprehensive analysis of the physics of gravitational waves, exploring both the theoretical foundations and the most recent experimental advances. After a general introduction to the theory of general relativity and its major implications, the article discusses the history of gravitational waves, from their prediction by Einstein to their actual detection. It then explains what gravitational waves are and how they interact with appropriate detectors. The main mechanisms of gravitational radiation emission are analyzed, with a focus on compact binary systems of compact objects, whose orbits typically evolve in three phases: inspiral, merger, and the final ringdown phase, each of these phases leaving distinct signatures in the emitted waves. The article highlights the fundamental role of the giant interferometers LIGO, Virgo, and KAGRA, true cathedrals of modern science, and revisits the historic event GW150914, the first direct detection of gravitational waves, which confirmed the predictions of general relativity and opened a new era for astronomy. This achievement was recognized with the 2017 Nobel Prize in Physics. Other observed events are also discussed, along with their astrophysical sources, and the possibility of detecting gravitational waves of cosmological origin, originating from the Big Bang itself. Finally, current and future projects are analyzed, including observatories based on increasingly sophisticated interferometers, as well as proposals for alternative detection methods, illustrating how gravitational-wave astronomy is shaping the present and future of our exploration of the universe. In concluding, the detection of gravitational waves is set in a broader context by examining the discoveries across the electromagnetic spectrum, thereby illustrating the complementary perspectives these different observational channels provide. - oai:arXiv.org:2512.22679v1 - gr-qc - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Jos\'e P. S. Lemos - - - DC response of an interferometer topology with an L-shaped cavity: a tabletop study - https://arxiv.org/abs/2601.09764 - arXiv:2601.09764v1 Announce Type: cross -Abstract: A new interferometer topology for kilohertz gravitational-wave detection was recently proposed in [Zhang et al. Phys. Rev. X 13, 021019 (2023)]. The design is based on an L-shaped optical cavity pumped through a Sagnac-like vortex. We report a tabletop experiment that characterizes the interferometer's optical response near DC. When the laser frequency is locked to the resonance of the L-shaped cavity, we observe that the cavity input coupler becomes effectively transparent, yielding a simple Michelson-like response. Moreover, the Sagnac vortex separates into upper and lower paths, which behave as two independent pumping paths driving the cavity. These observations are in agreement with theoretical predictions. Our results provide an intuitive physical picture of this interferometer topology and offer insight into its lock acquisition strategy. - oai:arXiv.org:2601.09764v1 - physics.ins-det - astro-ph.IM - gr-qc - physics.optics - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Junlang Li, Jiehong Huang, Xinyao Guo, Haixing Miao, Yuchao Chen, Xiaoman Huang, Yuan Pan, Chenjie Zhou, Raffaele Flaminio, Jameson Graef Rollins, Bram Slagmolen, Fan Zhang, Teng Zhang, Mengyao Wang - - - Classical equipartition dynamics between axions and non-Abelian gauge fields - https://arxiv.org/abs/2601.09784 - arXiv:2601.09784v1 Announce Type: cross -Abstract: Motivated by axion-like inflation and its warm embedding within the Standard Model, we study the early stages of the energy transfer between an axion condensate and an SU(2) gauge ensemble, by employing non-linear classical real-time lattice simulations. The discretized equations of motion are worked out, elaborating on Gauss constraints. A numerical solution is implemented on the CosmoLattice platform. Adopting a quadratic potential, and omitting universe expansion for the moment, we establish initial exponential growth of the low-momentum gauge modes; damping of axion oscillations after some delay; and subsequent energy equipartition between axion and gauge ensembles. A clear difference between the SU(2) and U(1) dynamics is observed, likely associated with non-Abelian self-interactions. We elaborate on what this implies for the possible thermalization of the SU(2) ensemble. - oai:arXiv.org:2601.09784v1 - hep-ph - astro-ph.CO - hep-lat - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Kim V. Berghaus, Adrien Florio, M. Laine, Franz R. Sattler - - - Microscopic Description of Critical Bubbles - https://arxiv.org/abs/2601.09787 - arXiv:2601.09787v1 Announce Type: cross -Abstract: First-order phase transitions occur through the nucleation of critical bubbles of the stable phase within the metastable phase. Using holography, we present a fully microscopic description of these bubbles in a strongly coupled, four-dimensional gauge theory at finite temperature. In the gravitational dual, these bubbles correspond to static, inhomogeneous and unstable black-brane solutions with a localized deformation on the horizon. We construct these solutions across the entire metastable branch and compute the surface tension and the nucleation rate. We then compare these microscopic results with those obtained from a two-derivative effective action for the order parameter in two different scenarios. When the effective action is derived from the microscopic theory via holography, we find remarkable agreement. However, when the effective action is constrained only by the equation of state and dimensional analysis, significant discrepancies emerge. These discrepancies can be resolved if an additional constraint related to the surface tension is imposed. - oai:arXiv.org:2601.09787v1 - hep-th - astro-ph.CO - gr-qc - hep-ph - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Carlos Hoyos, David Mateos, Wilke van der Schee, Javier G. Subils - - - The Cosmic Neutrino Background is within Reach of Future Neutrino Telescopes - https://arxiv.org/abs/2601.09790 - arXiv:2601.09790v1 Announce Type: cross -Abstract: The cosmic neutrino background (C$\nu$B) can be boosted to high energies due to scatterings with energetic cosmic rays (CRs) across cosmological scales. Previous calculations focused on neutral current incoherent and coherent elastic scatterings of cosmic-ray protons off relic neutrinos. However, charged current interactions and deep inelastic scatterings are also expected to occur, which enhances the boosted relic neutrino fluxes on Earth. Here, we compute the \textit{total} diffuse boosted cosmic neutrino background (DBC$\nu$B) arising from CRs at all redshifts in the Universe, accounting for neutral current and charged current elastic and deep inelastic scatterings. We find that IceCube already places an upper limit on the cosmic neutrino background overdensity in cosmological scales of ~$\mathcal{O}(100-1000)$ at $E_{\nu}=10^{10}$ GeV, for a lightest neutrino mass of $m_{\nu} \gtrsim 0.1$ eV. We further show that IceCube-Gen2 could test $\mathcal{O}(1-10)$ C$\nu$B overdensities, and the combination of $10$ future neutrino telescopes with similar sensitivity would allow us to test the $\Lambda$CDM expected C$\nu$B density for a lightest neutrino mass compatible with the KATRIN bound. - oai:arXiv.org:2601.09790v1 - hep-ph - astro-ph.CO - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Gonzalo Herrera, Shunsaku Horiuchi, Xiaolin Qi, Ian M. Shoemaker - - - Multibanded Reduced Order Quadrature Techniques for Gravitational Wave Inference - https://arxiv.org/abs/2601.09819 - arXiv:2601.09819v1 Announce Type: cross -Abstract: Reduced-order quadrature (ROQ) is commonly used to speed up parameter estimation in gravitational wave astronomy; however, the construction of ROQ bases can be computationally costly, particularly for longer duration signals. We propose a modified construction strategy based on PyROQ that accelerates this process by performing the basis search using multiband waveforms, without compromising the desired likelihood speed and accuracy. We use this altered method to construct a set of ROQs in the sub-solar mass range using the \texttt{IMRPhenomXAS\_NRTidalV3} waveform. We find a 20\% to 30\% decrease in basis size and a $\sim 10$ times decrease in basis construction time. We verify the altered method preserves the likelihood accuracy and mantains consitent parameter estimation results. - oai:arXiv.org:2601.09819v1 - gr-qc - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Murdoc Newell, Alexis Boudon, Hong Qi - - - Very-High-Frequency Gravitational Waves from Multi-Monodromy Inflation - https://arxiv.org/abs/2601.09834 - arXiv:2601.09834v1 Announce Type: cross -Abstract: We show that in multi-stage axion monodromy inflation an interruption near the end of the penultimate stage can lead to a spike in the gravitational wave background. These gravitational waves are in the frequency range and with an amplitude accessible to proposed terrestrial detectors such as the Einstein Telescope, Cosmic Explorer, and future Levitated Sensor Detector experiments. - oai:arXiv.org:2601.09834v1 - hep-ph - astro-ph.CO - gr-qc - hep-th - quant-ph - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Guido D'Amico, Andrew A. Geraci, Nemanja Kaloper, Alexander Westphal - - - Reinforcement Learning to Discover a NorthEast Monsoon Index for Monthly Rainfall Prediction in Thailand - https://arxiv.org/abs/2601.10181 - arXiv:2601.10181v1 Announce Type: cross -Abstract: Climate prediction is a challenge due to the intricate spatiotemporal patterns within Earth systems. Global climate indices, such as the El Ni\~no Southern Oscillation, are standard input features for long-term rainfall prediction. However, a significant gap persists regarding local-scale indices capable of improving predictive accuracy in specific regions of Thailand. This paper introduces a novel NorthEast monsoon climate index calculated from sea surface temperature to reflect the climatology of the boreal winter monsoon. To optimise the calculated areas used for this index, a Deep Q-Network reinforcement learning agent explores and selects the most effective rectangles based on their correlation with seasonal rainfall. Rainfall stations were classified into 12 distinct clusters to distinguish rainfall patterns between southern and upper Thailand. Experimental results show that incorporating the optimised index into Long Short-Term Memory models significantly improves long-term monthly rainfall prediction skill in most cluster areas. This approach effectively reduces the Root Mean Square Error for 12-month-ahead forecasts. - oai:arXiv.org:2601.10181v1 - cs.LG - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Kiattikun Chobtham - - - The recipe for the degrees of freedom - https://arxiv.org/abs/2601.10288 - arXiv:2601.10288v1 Announce Type: cross -Abstract: We consider the question of counting the degrees of freedom in theoretical models, with an emphasis on theories of fields and gravity. Among the possible approaches, the Hamiltonian formulation remains one of the most systematic and robust tools. However, it can easily become long and technically involved. In this work, we present a broadly applicable recipe to find the degrees of freedom directly, based on the Lagrangian formulation. We compare it to the standard approaches, highlight the challenges that may arise in the latter, and demonstrate that the proposed method leads to transparent insights about the dynamical nature of theory in a quick, simple, and straight-forward way. - oai:arXiv.org:2601.10288v1 - hep-th - astro-ph.CO - gr-qc - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Anamaria Hell, Elisa G. M. Ferreira, Dieter Lust, Misao Sasaki - - - Effects of spontaneous Lorentz Symmetry breaking on Letelier-AdS charged black boles within Kalb-Ramond gravity - https://arxiv.org/abs/2601.10303 - arXiv:2601.10303v1 Announce Type: cross -Abstract: In this study, we investigate the geodesic motion of massless particles -- specifically photons -- in the spacetime of a charged anti-de Sitter (AdS) black hole (BH) surrounded by a cloud of strings (CoS) within the framework of Kalb-Ramond (KR) gravity. We analyze the effective potential that governs photon trajectories, explore the properties and location of the photon sphere (PS), and examine the effective radial force acting on photons. The resulting BH shadow is also studied, highlighting the roles of both the CoS parameter $\alpha$ and the KR field parameter $\ell$ in shaping its geometry. We constrain these parameters using observational data from M87* and Sgr A* obtained by the Event Horizon Telescope (EHT). Furthermore, we extend our investigation to the motion of neutral test particles in the same gravitational background. By examining the impact of the CoS and KR field, we show how these additional fields modify the dynamics relative to standard charged BH scenarios. Finally, we study the fundamental frequencies associated with quasiperiodic oscillations (QPOs) of test particles, demonstrating how these frequencies are affected by the presence of the CoS and KR field. Our results reveal the rich structure of AdS-BH spacetimes influenced by string clouds and antisymmetric tensor fields, with potential observational consequences in gravitational wave and BH imaging astronomy. - oai:arXiv.org:2601.10303v1 - gr-qc - astro-ph.HE - hep-th - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Faizuddin Ahmed, Ahmad Al-Badawi, \.Izzet Sakall{\i} - - - Charged Simpson-Visser AdS Black Holes: Geodesic Structure and Thermodynamic Properties - https://arxiv.org/abs/2601.10469 - arXiv:2601.10469v1 Announce Type: cross -Abstract: In this article, we apply the Simpson-Visser (SV) regularization scheme to Anti-de Sitter (AdS) charged black holes and investigate the resulting spacetime geometry in detail, with emphasis on both geodesic structure and thermodynamic behavior. In particular, we analyze the motion of massless particle, focusing on key features such as the photon sphere, black hole shadow, photon trajectory and the dynamics of charged particles, including the characteristics of the circular and type of orbits. Furthermore, we compare the theoretical predictions of the charged SV-AdS black hole with recent observations reported by the Event Horizon telescope (EHT) for M87* and Sgr~A*. Beyond the geodesic analysis, we explore the thermodynamics of the regularized charged SV-AdS black hole by deriving essential quantities such as the Hawking temperature, Gibbs free energy, and specific heat capacity. Through a systematic examination of these thermodynamic variables, we demonstrate how the regularization parameter inherent in the SV regularization influences particle dynamics, stability conditions, and the overall thermal properties of the modified black hole solution. This comprehensive study highlights the interplay between regularization effects and the physical observables associated with charged AdS black holes. - oai:arXiv.org:2601.10469v1 - gr-qc - astro-ph.HE - hep-th - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Faizuddin Ahmed, Ahmad Al-Badawi, Mohsen Fathi - - - From Weibel seeds to collisionless dynamos beyond pair-plasmas - https://arxiv.org/abs/2601.10472 - arXiv:2601.10472v1 Announce Type: cross -Abstract: Bridging the spatiotemporal scales of magnetic seed field generation and subsequent dynamo amplification in the weakly collisional intracluster medium presents an extreme numerical challenge. We perform collisionless turbulence simulations with initially unmagnetized electrons that capture both magnetic seed generation via the electron Weibel instability and the ensuing dynamo amplification. Going beyond existing pair-plasma studies, we use an ion-to-electron mass ratio of 100 for which we find electron and ion dynamics are sufficiently decoupled. These simulations are enabled by the 10-moment collisionless fluid solver of Gkeyll, which evolves the full pressure tensor for all species. The electron heat-flux closure regulates pressure isotropization and effectively sets the magnetic Reynolds number. We investigate how the strength of of the closure influences the transition between a regime reminiscent of previous kinetic pair-plasma simulations and a more MHD-like dynamo regime. - oai:arXiv.org:2601.10472v1 - physics.plasm-ph - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Lise Hanebring, James Juno, Ammar Hakim, Jason M. TenBarge, Istvan Pusztai - - - Numerical simulations of oscillating and differentially rotating neutron stars - https://arxiv.org/abs/2601.10550 - arXiv:2601.10550v1 Announce Type: cross -Abstract: The remnants of binary neutron star mergers are expected to be massive, rapidly rotating stars whose oscillations produce gravitational waves in the kilohertz band. The degree of differential rotation and the rotation profiles strongly influence their structure, stability and oscillation spectrum, and must therefore be taken into account when modeling their dynamics. We extend the pseudospectral code ROXAS (Relativistic Oscillations of non-aXisymmetric neutron stArS) to enable the dynamical evolution of oscillating, differentially rotating neutron stars. Using the updated code, we aim to study the star's oscillation frequencies. We extend the previous formalism, based on primitive variables and the conformal flatness approximation, to differential rotation. Within this framework, we run a series of axisymmetric and non-axisymmetric simulations of perturbed, differentially rotating neutron stars with different rotation rates, and extract their oscillation frequencies. Axisymmetric modes, as well as those under the Cowling approximation, show excellent agreement with published results. We show that the secondary fundamental mode in the Cowling approximation is an artifact that does not appear in dynamical spacetimes. In addition, we provide, for the first time, frequency values for non-axisymmetric modes in differentially rotating configurations evolved in conformal flatness. This extension broadens the range of physical scenarios that can be studied with ROXAS, and represents a step toward more realistic modeling of post-merger remnants and their gravitational-wave emission. - oai:arXiv.org:2601.10550v1 - gr-qc - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Santiago Jaraba, J\'er\^ome Novak, Micaela Oertel - - - Multiple Populations and a CH Star Found in the 300S Globular Cluster Stellar Stream - https://arxiv.org/abs/2401.02476 - arXiv:2401.02476v2 Announce Type: replace -Abstract: Milky Way globular clusters (GCs) display chemical enrichment in a phenomenon called multiple stellar populations (MSPs). While the enrichment mechanism is not fully understood, there is a correlation between a cluster's mass and the fraction of enriched stars found therein. However, present-day GC masses are often smaller than their masses at the time of formation due to dynamical mass loss. In this work, we explore the relationship between mass and MSPs using the stellar stream 300S. We present the chemical abundances of eight red giant branch member stars in 300S with high-resolution spectroscopy from Magellan/MIKE. We identify one enriched star characteristic of MSPs and no detectable metallicity dispersion, confirming that the progenitor of 300S was a globular cluster. The fraction of enriched stars (12.5\%) observed in our 300S stars is less than the 50\% of stars found enriched in Milky Way GCs of comparable present-day mass ($\sim10^{4.5}$\msun). We calculate the mass of 300S's progenitor and compare it to the initial masses of intact GCs, finding that 300S aligns well with the trend between the system mass at formation and enrichment. 300S's progenitor may straddle the critical mass threshold for the formation of MSPs and can therefore serve as a benchmark for the stellar enrichment process. Additionally, we identify a CH star, with high abundances of \textit{s}-process elements, probably accreted from a binary companion. The rarity of such binaries in intact GCs may imply stellar streams permit the survival of binaries that would otherwise be disrupted. - oai:arXiv.org:2401.02476v2 - astro-ph.GA - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sam A. Usman, Alexander P. Ji, Ting S. Li, Andrew B. Pace, Lara R. Cullinane, Gary S. Da Costa, Sergey E. Koposov, Geraint F. Lewis, Daniel B. Zucker, Vasily Belokurov, Joss Bland-Hawthorn, Peter S. Ferguson, Terese T. Hansen, Guilherme Limberg, Sarah L. Martell, Madeleine McKenzie, Joshua D. Simon - - - Unified Origin of Curvature Perturbation and Baryon Asymmetry of the Universe - https://arxiv.org/abs/2410.07694 - arXiv:2410.07694v3 Announce Type: replace -Abstract: We propose a unified framework that describes both the curvaton mechanism for generating primordial density fluctuations and the Affleck-Dine (AD) mechanism for baryogenesis. By introducing a complex scalar field (AD field) carrying a baryon/lepton number and its potential consisting of quadratic and quartic terms with a small baryon/lepton-number-violating mass term, we investigate the evolution of the scalar field during the radiation-dominated era following inflation. We set the initial conditions such that the quartic term dominates the scalar potential, and the angular component of the AD field is non-zero. We focus on a scenario where the AD field sufficiently dominates the energy density of the universe before its decay. We show that the radial component of the AD field can be identified with the curvaton to solely produce the Planck normalized scalar power spectrum while the evolution of the angular component is crucial for generating the observed baryon asymmetry of the universe. Additionally, we find that the amplitude of scalar bispectrum $f_{NL}$ is negative, which is consistent with the current Planck data and testable in future observations such as CMB-S4, LiteBIRD, LSS, and 21-cm experiments. In our estimation of the scalar power spectrum and bispectrum, we develop a novel analytical scheme for computing scalar fluctuations based on the $\delta N$ formalism, which allows us to deal with the evolution of curvaton with polynomial potential more accurately in comparison to the existing analytical methods. - oai:arXiv.org:2410.07694v3 - astro-ph.CO - hep-ph - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1007/jhep01(2026)082 - JHEP01(2026)082 - Anish Ghoshal, Abhishek Naskar, Nobuchika Okada - - - Neutrino and pair creation in reconnection-powered coronae of accreting black holes - https://arxiv.org/abs/2410.12638 - arXiv:2410.12638v5 Announce Type: replace -Abstract: A ubiquitous feature of accreting black hole systems is their hard X-ray emission which is thought to be produced through Comptonization of soft photons by electrons and positrons in the vicinity of the black hole, in a region with optical depth of order unity. The origin and composition of this Comptonizing region, known as the corona, is a matter open for debate. In this paper we investigate the role of relativistic protons accelerated in black-hole magnetospheric current sheets for the pair enrichment and neutrino emission of AGN coronae. Our model has two free parameters, namely the proton plasma magnetization $\sigma_{\rm p}$, which controls the peak energy of the neutrino spectrum, and the Eddington ratio $\lambda_{\rm X, Edd}$ (defined as the ratio between X-ray luminosity $L_{\rm X}$ and Eddington luminosity $L_{\rm Edd}$), which controls the amount of energy transferred to secondary particles. For sources with $\lambda_{\rm X, Edd} \gtrsim \lambda_{\rm Edd, crit}$ (where $\lambda_{\rm Edd, crit} \sim 10^{-1}$ for $\sigma_{\rm p}=10^5$ or $\sim 10^{-2}$ for $\sigma_{\rm p}=10^7$), proton-photon interactions and $ \gamma \gamma$ annihilation produce enough secondary pairs to achieve Thomson optical depths $\tau_{\rm T} \sim 0.1-10$. In the opposite case of $\lambda_{\rm X, Edd} \lesssim \lambda_{\rm Edd, crit}$, the coronal pairs cannot originate only from hadronic interactions. Additionally, we find that the neutrino luminosity scales as $L^2_{\rm X}/L_{\rm Edd}$ for $\lambda_{\rm X, Edd} \lesssim \lambda_{\rm Edd, crit}$, while it is proportional to $L_{\rm X}$ for higher $\lambda_{\rm X, Edd}$ values. We apply our model to four Seyfert galaxies, including NGC 1068, and discuss our results in light of recent IceCube observations. - oai:arXiv.org:2410.12638v5 - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - D. Karavola, M. Petropoulou, D. F. G. Fiorillo, L. Comisso, L. Sironi - - - Gravitational-Wave Signatures of Nonstandard Neutrino Properties in Collapsing Stellar Cores - https://arxiv.org/abs/2412.02750 - arXiv:2412.02750v2 Announce Type: replace -Abstract: We present a novel multi-messenger approach for probing nonstandard neutrino properties through the detection of gravitational waves (GWs) from collapsing stellar cores and associated supernova explosions. We show that neutrino flavor conversion inside the proto-neutron star (PNS), motivated by physics Beyond the Standard Model (BSM), can significantly boost PNS convection. This effect leads to large-amplitude GW emission over a wide frequency range during an otherwise relatively quiescent GW phase shortly after core bounce. Such a signal provides a promising new avenue for exploring nonstandard neutrino phenomena and other BSM physics impacting PNS convection. - oai:arXiv.org:2412.02750v2 - astro-ph.HE - gr-qc - hep-ph - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1103/rv17-jm6g - Jakob Ehring (Academia Sinica, Taipei City, Taiwan, MPI Physics, Garching, Germany, MPI Astrophysics, Garching, Germany), Sajad Abbar (MPI Physics, Garching, Germany), H. -Thomas Janka (MPI Astrophysics, Garching, Germany), Georg Raffelt (MPI Physics, Garching, Germany), Ko Nakamura (Fukuoka University, Japan), Kei Kotake (Fukuoka University, Japan, University of Wroclaw, Poland) - - - Probing the Limits of Habitability: A Catalog of Rocky Exoplanets in the Habitable Zone - https://arxiv.org/abs/2501.14054 - arXiv:2501.14054v2 Announce Type: replace -Abstract: While most of the 6000 discovered exoplanets are highly unlike the Earth, the first rocky worlds in the Habitable Zone (HZ) provide intriguing targets for the search for life in the cosmos. As detections increase, it is critical to test the empirical HZ as well as its limits using known exoplanets. However, there is not yet a list of rocky worlds that observers can use to test the limits of surface habitability. - We analysed data from Gaia DR3 and the NASA Exoplanet Archive (NEA) of all known exoplanets, identifying future targets to test limits of habitability through i) orbits near the edges of the HZ, ii) similar irradiation environments to modern Earth, and iii) large eccentricities. We prioritize targets for transmission observations, light curve measurements, and direct imaging, identify the oldest HZ rocky worlds based on the NEA and complementary literature data, and provide theoretical limits for the empirical HZ and a 3D-HZ for each system. - Our analysis shows 45 rocky worlds in the empirical HZ and 24 in a narrower 3D-HZ. For context, we compare their demographics to those of the full catalog of exoplanets in the NEA. The resulting list of rocky exoplanet targets in the HZ will allow observers to shape and optimize search strategies with space- and ground-based telescopes -- such as the James Webb Space Telescope (JWST), Extremely Large Telescope (ELT), Habitable Worlds Observatory (HWO), and LIFE -- and design new observing strategies and instruments to explore these worlds, addressing the question of the limits of exoplanet surface habitability. - oai:arXiv.org:2501.14054v2 - astro-ph.EP - astro-ph.IM - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Abigail Bohl, Lucas Lawrence, Gillis Lowry, Lisa Kaltenegger - - - Detectability of dark matter subhalo impacts in Milky Way stellar streams - https://arxiv.org/abs/2502.07781 - arXiv:2502.07781v3 Announce Type: replace -Abstract: Stellar streams are a promising way to probe the gravitational effects of low-mass dark matter (DM) subhalos. In recent years, there has been a remarkable explosion in the number of stellar streams detected in the Milky Way, and hundreds more may be discovered with future surveys such as LSST. Studies of DM subhalo impacts on streams have so far focused on a few of the thinnest and brightest streams, and it is not known how much information can be gained from the others. In this work, we develop a method to quickly estimate the minimum detectable DM subhalo mass of a given stream, depending on its width, length, distance, and stellar density. We use an analytic model for the impacts and apply a test statistic to determine whether they are detectable. We consider several observational scenarios, based on current and future surveys including Gaia, DESI, Via, and LSST. We find that at 95% confidence level, a stream like GD-1 has a minimum detectable subhalo mass of $\sim 6\times 10^6~\mathrm{M}_\odot$ in Gaia data and $\sim 8\times 10^5~\mathrm{M}_\odot$ with LSST 10 year sensitivity. Applying our results to confirmed Milky Way streams, we rank order them by their sensitivity to DM subhalos and identify promising ones for further study. - oai:arXiv.org:2502.07781v3 - astro-ph.GA - astro-ph.CO - hep-ph - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Junyang Lu, Tongyan Lin, Mukul Sholapurkar, Ana Bonaca - - - Rates of Strongly Lensed Tidal Disruption Events - https://arxiv.org/abs/2502.19495 - arXiv:2502.19495v2 Announce Type: replace -Abstract: In the coming years, surveys such as the Rubin Observatory's Legacy Survey of Space and Time (LSST) are expected to increase the number of observed Tidal Disruption Events (TDEs) substantially. We employ Monte Carlo integration to calculate the unlensed and lensed TDE rate as a function of limiting magnitude in $u$, $g$, $r$, and $i$-bands. We investigate the impact of multiple luminosity models, black hole mass functions (BHMFs), and flare temperatures on the TDE rate. Notably, this includes a semi-analytical model, which enables the determination of the TDE temperature in terms of black hole (BH) mass. We predict the highest unlensed TDE rate to be in $g$-band. It ranges from $16$ to $5,440\;\mathrm{yr}^{-1}\;(20,000\;\mathrm{deg}^2)^{-1}$ for the Zwicky Transient Facility, being more consistent with the observed rate at the low end. For LSST, we expect a rate in $g$-band between $3,580$ and $82,060\;\mathrm{yr}^{-1}\;(20,000\;\mathrm{deg}^2)^{-1}$. A higher theoretical prediction is understandable, as we do not consider observational effects such as completeness. The unlensed and lensed TDE rates are insensitive to the redshift evolution of the BHMF, even for LSST limiting magnitudes. The best band for detecting lensed TDEs is also $g$-band. Its predicted rates range from $0.43$ to $15\;\mathrm{yr}^{-1}\;(20,000\;\mathrm{deg}^2)^{-1}$ for LSST. The scatter of predicted rates reduces when we consider the fraction of lensed TDEs; that is, a few in ten thousand TDEs will be lensed. Despite the large scatter in the rates of lensed TDEs, our comprehensive considerations of multiple models suggest that lensed TDEs will occur in the $10$-year LSST lifetime, providing an exciting prospect for detecting such events. We expect the median redshift of a lensed TDE to be between $1.5$ and $2$. In this paper, we additionally report on lensed TDE properties, such as the BH mass and time delays. - oai:arXiv.org:2502.19495v2 - astro-ph.HE - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-sa/4.0/ - 10.1051/0004-6361/202554367 - A&A 701, A142 (2025) - E. Mamuzic, T. Ryu, S. H. Suyu, K. Szekerczes, S. Huber, L. Dai, M. Oguri - - - The galaxy-environment connection revealed by constrained simulations - https://arxiv.org/abs/2503.14732 - arXiv:2503.14732v2 Announce Type: replace -Abstract: The evolution of galaxies is known to be connected to their position within the large-scale structure and their local environmental density. We investigate the relative importance of these using the underlying dark matter density field extracted from the Constrained Simulations in BORG (CSiBORG) suite of constrained cosmological simulations. We define cosmic web environment through both dark matter densities averaged on a scale up to 16 Mpc/h, and through cosmic web location identified by applying DisPerSE to the CSiBORG haloes. We correlate these environmental measures with the properties of observed galaxies in large surveys using optical data (from the NASA-Sloan Atlas) and 21-cm radio data (from ALFALFA). We find statistically significant correlations between environment and colour, neutral hydrogen gas (HI) mass fraction, star formation rate and S\'ersic index. Together, these correlations suggest that bluer, star forming, HI rich, and disk-type galaxies tend to reside in lower density areas, further from filaments, while redder, more elliptical galaxies with lower star formation rates tend to be found in higher density areas, closer to filaments. We find analogous trends with the quenching of galaxies, but notably find that the quenching of low mass galaxies has a greater dependence on environment than the quenching of high mass galaxies. We find that the relationship between galaxy properties and the environmental density is stronger than that with distance to filament, suggesting that environmental density has a greater impact on the properties of galaxies than their location within the larger-scale cosmic web. - oai:arXiv.org:2503.14732v2 - astro-ph.GA - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Catherine Gallagher, Tariq Yasin, Richard Stiskalek, Harry Desmond, Matt J. Jarvis - - - Chemical Abundances in the Metal-Poor Globular Cluster ESO 280-SC06: A Formerly Massive, Tidally Disrupted Globular Cluster - https://arxiv.org/abs/2506.15664 - arXiv:2506.15664v3 Announce Type: replace -Abstract: We present the first high-resolution abundance study of ESO 280-SC06, one of the least luminous and most metal-poor gravitationally bound Milky Way globular clusters. Using Magellan/MIKE spectroscopy for ten stars, we confirm the cluster's low metallicity as [Fe/H] = $-2.54 \pm 0.06$ and the presence of a nitrogen-enhanced star enriched by binary mass transfer. We determine abundances or abundance upper limits for 21 additional elements from the light, alpha, odd-Z, iron peak, and neutron-capture groups for all ten stars. We find no spread in neutron-capture elements, unlike previous trends identified in some metal-poor globular clusters such as M15 and M92. Eight of the ten stars have light-element abundance patterns consistent with second-population globular cluster stars, which is a significantly larger second-population fraction than would be expected from the low present-day mass of $10^{4.1}$ Msun. We estimate the initial mass of the cluster as $10^{5.4 - 5.7}$ Msun based on its orbit in the Milky Way. A preferential loss of first-population stars could explain the high fraction of second-population stars at the present time. Our results emphasize the importance of considering mass loss when studying globular clusters and their enrichment patterns. - oai:arXiv.org:2506.15664v3 - astro-ph.GA - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Sam A. Usman, Alexander P. Ji, Jandrie Rodriguez, Jeffrey D. Simpson, Sarah L. Martell, Ting S. Li, Ana Bonaca, Shivani P. Shah, Madeleine McKenzie - - - Non-Gaussian statistics in galaxy weak lensing: compressed three-point correlations and cosmological forecasts - https://arxiv.org/abs/2506.19811 - arXiv:2506.19811v3 Announce Type: replace -Abstract: Building on previous developments of a harmonic decomposition framework for computing the three-point correlation function (3PCF) of projected scalar fields over the sky, this work investigates how much cosmological information is contained in these higher-order statistics. We perform a forecast to determine the number of harmonic multipoles required to capture the full information content of the 3PCF in the context of galaxy weak lensing, finding that only the first few multipoles are sufficient to capture the additional cosmological information provided by the 3PCF. This study addresses a critical practical question: to what extent can the high-dimensional 3PCF signal be compressed without significant loss of cosmological information? Since the different multipoles contain highly redundant information, we apply a principal component analysis (PCA) which further reduces its dimensionality and preserving information. We also account for non-linear parameter degeneracies using the DALI method, an extension of Fisher forecasting that includes higher-order likelihood information. Under optimistic settings, we find that the 3PCF considerably improves the constraining power of the 2PCF for $\Omega_m$, reaching a 20% improvement. Other parameters also benefit, mainly due to their degeneracy with the matter abundance. For example, with our chosen scale cuts for galaxy sources at $z = 0.5$, we find that $\sigma_8$ is more tightly constrained, whereas $S_8$ and $w_0$ are not. Finally, we construct analytical Gaussian covariance matrices that can serve as a first step toward developing semi-analytical, semi-empirical alternatives to sample covariances. - oai:arXiv.org:2506.19811v3 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1088/1475-7516/2025/10/006 - JCAP10(2025)006 - Sofia Samario-Nava, Alejandro Aviles, Juan Carlos Hidalgo - - - Angular-momentum pairs in spherical systems: applications to the Galactic centre - https://arxiv.org/abs/2507.10551 - arXiv:2507.10551v2 Announce Type: replace -Abstract: Consider a system of point masses in a spherical potential. In such systems objects execute planar orbits covering two-dimensional rings or annuli, represented by the angular-momentum vectors, which slowly reorient due to the persistent weak gravitational interaction between different rings. This process, called vector resonant relaxation, is much faster than other processes which change the size/shape of the rings. The interaction is stron9gest between objects with closely aligned angular-momentum vectors. In this paper, we show that nearly parallel angular-momentum vectors may form stable bound pairs in angular-momentum space. We examine the stability of such pairs against an external massive perturber, and determine the critical separation analogous to the Hill radius or tidal radius in the three-body problem, where the angular-momentum pairs are marginally disrupted, as a function of the perturber's mass, the orbital inclination, and the radial distance. Angular-momentum pairs or multiples closer than the critical inclination will remain bound and evolve together in angular-momentum-direction space under any external influence, such as anisotropic density fluctuations, or massive perturbers. This study has applications in various astrophysical contexts, including galactic nuclei, in particular the Milky Way's Galactic centre, globular clusters, or planetary systems. In nuclear star clusters with a central super-massive black hole, we apply this criterion to the disc of young, massive stars, and show that clusters in angular-momentum space may be used to constrain the presence of intermediate-mass black holes or the mass of the nearby gaseous torus. - oai:arXiv.org:2507.10551v2 - astro-ph.GA - astro-ph.IM - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1093/mnras/stag039 - Taras Panamarev, Yonadav Barry Ginat, Bence Kocsis - - - A Nitrogen-rich AGN Powering a Large Ionizing Bubble at z=8.63 - https://arxiv.org/abs/2508.01372 - arXiv:2508.01372v2 Announce Type: replace -Abstract: We report the detection of Ly${\alpha}$ in CANUCS-LRD-z8.6, a recently discovered AGN at z = 8.63 by Tripodi et al. (2024), in new NIRSpec/MSA G140H/F070LP observations. We detect broad Ly${\alpha}$ emission (FWHM $= 1540 \pm 260$ km/s) near the systemic velocity, which suggests a large ionizing bubble considering that the universe is almost fully neutral at the redshift. Through Ly${\alpha}$ line-shape modeling assuming a Stromgren sphere, we find a large bubble radius, $R_b = 1.5^{+0.3}_{-0.2}$ pMpc, and a moderately high Ly${\alpha}$ escape fraction, $f_{esc} = 11 \pm 3$ %. The intrinsic line width is inferred to be broad ($2200 \pm 280$ km/s), likely originating in the broad-line region. Existing data indicate that CANUCS-LRD-z8.6 is within a mild overdensity, $\delta = 1.8^{+3.0}_{-0.6}$, suggesting that other galaxies in its proximity might have contributed to the formation of the bubble. The high N IV]${\lambda}$1488 / C IV${\lambda}$1548 and N IV]${\lambda}$1488 / O III]${\lambda}$1661 line ratios measured in existing NIRSpec/PRISM data indicate nitrogen enrichment in this metal-poor, low-luminosity AGN. The spectroscopic features are overall similar to other nitrogen-rich galaxies discovered in the literature, such as GN-z11 and GHZ2/GLASSz12. This suggests that CANUCS-LRD-z8.6 may represent one of the evolutionary phases of those nitrogen-rich galaxies. - oai:arXiv.org:2508.01372v2 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Takahiro Morishita, Massimo Stiavelli, Charlotte A. Mason, Roberta Tripodi, Marco Chiaberge, Stefan Schuldt, Chris J. Willott, Yechi Zhang - - - Cosmological Constraints on Neutrino Masses in a Second-Order CPL Dark Energy Model - https://arxiv.org/abs/2508.16238 - arXiv:2508.16238v2 Announce Type: replace -Abstract: Recent DESI results indicate a strong preference for dynamical dark energy (DE) when baryon acoustic oscillation (BAO) measurements are combined with supernovae (SNe) and cosmic microwave background (CMB) data using the Chevallier-Polarski-Linder (CPL) parameterization. We analyze the exponential (EXP) parameterization, which introduces a second-order correction to CPL. We determine and compare the 95% upper bounds on the sum of neutrino masses for three dark energy (DE) models -- $\Lambda$CDM, CPL, and EXP -- across four neutrino mass hierarchies (1 massive/2 massless, degenerate, normal, inverted) and multiple dataset combinations (CMB$+$BAO, CMB$+$BAO$+$PantheonPlus, CMB$+$BAO$+$DESY5), employing both Bayesian and frequentist frameworks with physical lower limits from oscillation experiments (0.059 eV and 0.11 eV). Our results show that CPL yields tighter ($\lesssim10$%) bounds compared to EXP. We further confirm earlier findings that neutrino mass constraints are only mildly sensitive to the assumed hierarchy and that the frequentist bounds are tighter than Bayesian ones. Furthermore, the imposed oscillation lower limits, the datasets used and the DE parameterizations play a crucial role in the inferred cosmological neutrino mass bounds. For the datasets, hierarchies, and DE parameterizations considered, we find no statistically significant evidence for nonzero neutrino mass consistent with oscillation lower limits. - oai:arXiv.org:2508.16238v2 - astro-ph.CO - hep-ph - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Shubham Barua, Shantanu Desai - - - Topology of the Superconducting Heart of Neutron Stars: Effects of Microphysics and Gravitational-Wave Signatures - https://arxiv.org/abs/2508.18363 - arXiv:2508.18363v2 Announce Type: replace -Abstract: We present a general-relativistic study of the distribution of proton superconductivity in strongly magnetized neutron stars (NSs), using the XNS code to solve the coupled Einstein-Maxwell equations. We investigate equilibrium configurations with both toroidal and poloidal magnetic field geometries and incorporate complex many-body effects through microscopically derived proton pairing gaps. The models employ equations of state (EoS) obtained from microscopic many-body theory - including realistic two- and three-body nuclear interactions - as well as from relativistic mean-field approaches. We compare superconducting topologies across our collection of EoS and explore the influences of magnetic field geometry in stellar models parameterized by central density. Our models confirm the absence of $S$-wave superconductivity in the inner core and, importantly, reveal that non-superconducting regions exhibit complex three-dimensional geometries: doughnut-shaped for toroidal fields and prolate-shaped for poloidal fields -- spatial structures that are inherently absent in one-dimensional analyses. We also compute magnetic deformations and ellipticities for several millisecond pulsars (MSPs), estimating their continuous gravitational wave strain. While these MSPs remain undetectable by current detectors, next-generation instruments such as the Einstein Telescope and Cosmic Explorer may detect their signals, opening an observational window into internal superconductivity and internal magnetic field of NSs, as well as the fundamental microphysics of dense matter. - oai:arXiv.org:2508.18363v2 - astro-ph.HE - astro-ph.SR - gr-qc - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Mayusree Das (IISc), Armen Sedrakian (UWr, FIAS), Banibrata Mukhopadhyay (IISc) - - - HSTPROMO Internal Proper Motion Kinematics of Dwarf Spheroidal Galaxies: II. Velocity Anisotropy and Dark Matter Cusp Slope of Sculptor - https://arxiv.org/abs/2508.20711 - arXiv:2508.20711v2 Announce Type: replace -Abstract: We analyze three epochs of HST imaging over 20 years for the Sculptor dwarf spheroidal galaxy, measuring precise proper motions for 119 stars and combining them with 1760 existing line-of-sight velocities. This catalog yields the first radially-resolved 3D velocity dispersion profiles for Sculptor. We confirm mild oblate rotation, with major-axis velocities reaching $\sim 2$ km s$^{-1}$ beyond 20.0 arcmin. Using a methodology similar to that in the first paper in this series, we solve the Jeans equations in oblate axisymmetric geometry to infer the galaxy's mass profile. Our modeling reveals a significant degeneracy due to the unknown galaxy inclination, which is overlooked under spherical symmetry assumptions. This degeneracy allows acceptable fits across a range of dark matter profiles, from cuspy to cored. While we do not directly constrain the inclination with our Jeans models, higher-order line-of-sight velocity moments provide useful additional constraints: comparisons with scalefree models from de Bruijne et al. (1996) favor highly flattened (more face-on) configurations. Adopting an inclination well consistent with these comparisons ($i = 57.1$ degrees), we find, alongside radial velocity anisotropy, a dark matter density slope of $\Gamma_{\rm dark} = 0.29^{+0.31}_{-0.41}$ within the radial extent of the 3D velocity data, ruling out a cusp with $\Gamma_{\rm dark} \leq -1$ at 99.8% confidence. This confidence increases for lower inclinations and decreases drastically for nearly edge-on configurations. The results qualitatively agree with $\Lambda$CDM, SIDM, and Fuzzy DM scenarios that predict core formation, while our specific measurements provide quantitative constraints on the prescriptions of feedback, cross sections, or particle masses required by these models, respectively. - oai:arXiv.org:2508.20711v2 - astro-ph.GA - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.3847/1538-4357/ae1f8a - Eduardo Vitral, Roeland P. van der Marel, Sangmo Tony Sohn, Jorge Pe\~narrubia, Ekta Patel, Laura L. Watkins, Mattia Libralato, Kevin McKinnon, Andrea Bellini, Andr\'es del Pino, Paul Bennet - - - Prospects and Limitations of PTAs Anisotropy Searches -- The Frequentist Case - https://arxiv.org/abs/2509.07074 - arXiv:2509.07074v2 Announce Type: replace -Abstract: Recent findings from several Pulsar Timing Array (PTA) collaborations point to the existence of a Gravitational Wave Background (GWB) at nanohertz frequencies. A key next step towards characterizing this signal and identifying its origin is to map the sky distribution of its power. Several strategies have been proposed to reconstruct this distribution using PTA data. In this work, we compare these different strategies to determine which one is best suited to detect GWB anisotropies of different topologies. We find that, for both localized and large-scale anisotropies, reconstruction methods based on pixel and radiometer maps are the most promising. However, in both scenarios, even the optimistically large anisotropic signals discussed in this work remain challenging to detect with near-future PTA sensitivities. For example, we find that for a GWB hotspot contributing to $80\%$ of the GWB power in the second frequency bin, detection probabilities reach at most $\mathcal{O}(10\%)$ for a PTA with noise properties comparable with the ones of the upcoming IPTA third data release. Finally, we consider the fundamental limitations that cosmic variance poses to these kinds of searches by deriving the smallest deviations from isotropy that could be detected by an idealized PTA with no experimental or pulsar noise. - oai:arXiv.org:2509.07074v2 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Thomas Konstandin, Anna-Malin Lemke, Andrea Mitridate, Enrico Perboni - - - BlackTHUNDER: Shedding light on a dormant and extreme little red dot at z=8.50 - https://arxiv.org/abs/2509.20455 - arXiv:2509.20455v2 Announce Type: replace -Abstract: Recent photometric surveys with JWST have revealed a significant population of mysterious objects with red colours, compact morphologies, frequent signs of active galactic nucleus (AGN) activity, and negligible X-ray emission. These 'Little Red Dots' (LRDs) have been explored through spectral and photometric studies, but their nature is still under debate. As part of the BlackTHUNDER survey, we have observed UNCOVER_20466, one of the most distant LRDs known (z=8.5), with the JWST/NIRSpec IFU. Previous JWST/NIRCam and JWST/NIRSpec MSA observations of this source revealed its LRD nature, as well as the presence of an AGN. Using our NIRSpec IFU data, we confirm that UNCOVER_20466 is an LRD (based on spectral slopes and compactness) that contains an overmassive black hole. However, our observed Balmer decrements do not suggest strong dust attenuation, resulting in a lower Hbeta-based bolometric luminosity and Eddington luminosity (~10%) than previously found. This source lies on local relations between M_BH-sigma_* and M_BH-M_Dyn, suggesting that this could be a progenitor of the core of a lower-redshift galaxy. We explore the possible evolution of this source, finding evidence for substantial black hole accretion in the past and a likely origin as a heavy seed at high redshift (~10^3Msol). Lyman-alpha emission is strongly detected, implying f_esc,Lya~30%. The extremely high [OIII]4363/Hgamma ratio is indicative of not only AGN photoionization and heating, but also extremely high densities (ne~10^7cm-3), suggesting that this black hole at such high redshift may be forming in an ultra-dense protogalaxy. - oai:arXiv.org:2509.20455v2 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Gareth C. Jones, Hannah \"Ubler, Roberto Maiolino, Xihan Ji, Alessandro Marconi, Francesco D'Eugenio, Santiago Arribas, Andrew J. Bunker, Stefano Carniani, St\'ephane Charlot, Giovanni Cresci, Kohei Inayoshi, Yuki Isobe, Ignas Juod\v{z}balis, Giovanni Mazzolari, Pablo G. P\'erez-Gonz\'alez, Michele Perna, Raffaella Schneider, Jan Scholtz, Sandro Tacchella - - - Probing the Star Formation Main Sequence down to 10$^{7} M_\odot$ at $1 < z < 9$ - https://arxiv.org/abs/2509.22871 - arXiv:2509.22871v2 Announce Type: replace -Abstract: The Main Sequence of Star-Forming Galaxies (SFGMS or MS) is a fundamental scaling relation that provides a global framework for studying galaxy formation and evolution, as well as insight into the complex star formation histories (SFHs) of individual galaxies. In this work, we combine large-area pre-JWST surveys (COSMOS2020, CANDELS), which probe high-$M_\star$ sources (${>10^9\,M_\odot}$), with SHARDS/CANDELS FAINT and JWST data from CANUCS, CEERS, JADES, and UNCOVER, to obtain a high-$z$, star formation rate (SFR) and stellar mass ($M_\star$) complete sample spanning both high- and low-$M_\star$ regimes. Completeness in both $M_\star$ and SFR is key to avoiding biases introduced by low-mass, highly star-forming objects. Our combined data set is 80% complete down to $10^{7.6}\,M_\odot$ at $z\sim1$ ($10^{8.8}\,M_\odot$ at $z\sim9$). The overall intrinsic MS slope (based on the SFR$_{100}$ and $M_\star$ derived with Dense Basis and nonparametric SFHs) shows little evolution up to $z\sim5$, with values $\sim0.7 - 0.8$. The slope in the low-$M_\star$ regime becomes steeper than that in the high-$M_\star$ end at least up to $z\sim5$, but the strength of this change is highly dependent on the assumptions made on the symmetry of the uncertainties in $M_\star$ and SFR. If real, the steepening suggests reduced star formation efficiency or declining gas content with decreasing $M_\star$. The transition between the low-$M_\star$ regime and the canonical MS occurs around $10^{9.5}\,M_\odot$, independent of $z$. This critical value may coincide with the assembly of galaxies' disks, which can provide a mechanism for self-regulation that stabilizes them against feedback. The intrinsic scatter is compatible with canonical estimates, also at low-$M_\star$, ranging from $0.2-0.3$ dex. This is indicative of rapid variations in star formation being averaged out over $\lesssim100$ Myr. - oai:arXiv.org:2509.22871v2 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Rosa M. M\'erida, Marcin Sawicki, Kartheik G. Iyer, Ga\"el Noirot, Chris J. Willott, Maru\v{s}a Brada\v{c}, Guillaume Desprez, Nicholas S. Martis, Adam Muzzin, Gregor Rihtar\v{s}i\v{c}, Ghassan T. E. Sarrouh, Jeremy Favaro, Gaia Gaspar, Anishya Harshan, Jon Jude\v{z} - - - Faraday Depolarization Study of a Radio Galaxy Using LOFAR Two-metre Sky Survey: Data Release 2 - https://arxiv.org/abs/2510.00440 - arXiv:2510.00440v2 Announce Type: replace -Abstract: We present a detailed depolarization analysis of the radio galaxy \texttt{ILTJ012215.21+254334.8} using polarimetric data from the \textit{LOFAR Two-metre Sky Survey} (LoTSS) Data Release 2 (DR2) catalogue. This source, with \textit{RM} $\sim$ 47 rad m$^{-2}$ and projected linear size $\sim$ 335 kpc at $z \approx 0.05$, serves as a pilot for systematic QU-fitting of unresolved LoTSS sources, building on prior single-target studies that established the need for multi-component Faraday models in complex magneto-ionic media. - Fitting five depolarization models to the LoTSS HBA (120-168 MHz) fractional polarization spectra reveals a decisively preferred three-component model (one Faraday-thin instrumental leakage, plus two external Faraday dispersions), demonstrating that LoTSS data alone can constrain moderate Faraday complexity in typical DR2 galaxies. Our results highlight turbulence and inhomogeneity in the foreground magneto-ionic medium and outline a path for population studies of LoTSS FR-I sources. - oai:arXiv.org:2510.00440v2 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Samantha Sneha Paul, Abhik Ghosh - - - Next-Generation Improvements in Giant Exoplanet Evolutionary and Structural Models - https://arxiv.org/abs/2510.08681 - arXiv:2510.08681v2 Announce Type: replace -Abstract: Many evolutionary models of giant exoplanets still rely on simplifying assumptions that are no longer adequate given detailed constraints from Jupiter, Saturn, and modern exoplanet observations. Here, we identify the key physical improvements required for next-generation planetary evolution models using our code, \texttt{APPLE}, which enables systematic emulation and extension of legacy studies. We quantify the effects of updated equations of state, helium rain, fuzzy cores, non-adiabatic and compositionally inhomogeneous envelopes, and improved atmospheric boundary conditions by first isolating the impact of each physical ingredient and then constructing combined baseline models for planets with masses between 0.3 and 4~$M_{\rm Jup}$ to assess their collective influence on planetary structure and observable properties. We find that the adoption of modern equations of state and realistic heavy-element distributions leads to systematic, but sometimes subtle, differences ($\sim 5$ to 10\%) in radius evolution, while helium rain and the treatment of convection can significantly alter thermal histories and atmospheric compositions (by $\sim$ 5 to 20\%). These updated physical processes must be incorporated into the next-generation exoplanet evolutionary models to achieve physically consistent interpretations of planetary observations. - oai:arXiv.org:2510.08681v2 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ankan Sur, Roberto Tejada Arevalo, Adam Burrows, Yi-Xian Chen - - - The GAPS programme at TNG LXXI. A sub-Neptune suitable for atmospheric characterization in a multiplanet and mutually inclined system orbiting the bright K dwarf TOI-5789 (HIP 99452) - https://arxiv.org/abs/2510.11490 - arXiv:2510.11490v3 Announce Type: replace -Abstract: Sub-Neptunes with planetary radii of $R_{p} \simeq 2-4 R_{\oplus}$ are the most common planets around solar-type stars in short-period ($P<100$ d) orbits. It is still unclear, however, what their most likely composition is, that is whether they are predominantly gas dwarfs or water worlds. The sub-Neptunes orbiting bright host stars are very valuable because they are suitable for atmospheric characterization, which can break the well-known degeneracy in planet composition from the planet bulk density, when combined with a precise and accurate mass measurement. Here we report on the characterization of the sub-Neptune TOI-5789 c, which transits in front of the bright ($V=7.3$ mag and $K_{s}=5.35$ mag) and magnetically inactive K1V dwarf HIP 99452 every 12.93 days, thanks to TESS photometry and 141 high-precision radial velocities obtained with the HARPS-N spectrograph. We find that its radius, mass, and bulk density are $R_{c}=2.86^{+0.18}_{-0.15} R_\oplus$, $M_{c}=5.00 \pm 0.50 M_\oplus$, and $\rho_{c}=1.16 \pm 0.23$ g cm$^{-3}$, and we show that TOI-5789 c is a promising target for atmospheric characterization with both JWST and, in the future, Ariel. By analyzing the HARPS-N radial velocities with different tools, we also detect three additional non-transiting planets, namely TOI-5789 b, d, and e, with orbital periods and minimum masses of $P_{b}=2.76$ d, $M_{b}\sin{i}=2.12 \pm 0.28 M_\oplus$, $P_{d}=29.6$ d, $M_{d}\sin{i}=4.29 \pm 0.68 M_\oplus$, and $P_{e}=63.0$ d, $M_{e}\sin{i}=11.61 \pm 0.97 M_\oplus$. TOI-5789 is a mutually inclined system as the difference between the orbital inclinations of planets b and c must be higher than $\sim4$ deg. Nevertheless, from sensitivity studies based on both the HARPS-N and archival HIRES radial-velocity measurements, we can exclude that these relatively high mutual inclinations are due to the perturbation by an outer gaseous giant planet. - oai:arXiv.org:2510.11490v3 - astro-ph.EP - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - A. S. Bonomo, L. Naponiello, A. Sozzetti, S. Benatti, I. Carleo, K. Biazzo, P. E. Cubillos, M. Damasso, C. Di Maio, C. Dorn, N. Hara, D. Polychroni, M. -L. Steinmeyer, K. A. Collins, S. Desidera, X. Dumusque, A. F. Lanza, B. S. Safonov, C. Stockdale, D. Turrini, C. Ziegler, L. Affer, M. D'Arpa, V. Fardella, A. Harutyunyan, V. Lorenzi, L. Malavolta, L. Mancini, G. Mantovan, G. Micela, F. Murgas, D. Nardiello, I. Pagano, E. Pall\'e, M. Pedani, M. Pinamonti, M. Rainer, G. Scandariato, R. Spinelli, T. Zingales - - - Orbit Elements from Kepler Solutions in Projective Coordinates - https://arxiv.org/abs/2511.12957 - arXiv:2511.12957v3 Announce Type: replace -Abstract: Closed-Form Kepler solutions in projective coordinates are used to define a corresponding set of eight orbit elements and obtain their governing equations for arbitrarily-perturbed two-body dynamics. The elements and their dynamics are singularity-free in all cases besides rectilinear motion (when angular momentum vanishes). The classic J2-perturbed two-body problem is developed and used for numerical verification. - oai:arXiv.org:2511.12957v3 - astro-ph.EP - math.DS - physics.class-ph - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Joseph T. A. Peterson, Manoranjan Majji, John L. Junkins - - - Topological Signatures of Heating and Dark Matter in the 21 cm Forest - https://arxiv.org/abs/2511.13092 - arXiv:2511.13092v2 Announce Type: replace -Abstract: We show that persistence-based topology of the 21 cm forest encodes information about Cosmic Dawn that is complementary to traditional amplitude- or correlation-based statistics. Applying topological data analysis to simulated one-dimensional forest spectra over a grid of X-ray heating efficiencies $f_X$ and warm-dark-matter masses $m_{\rm WDM}$ (which set the free-streaming scale), we construct persistence diagrams and Betti-0 curves that track the birth-merger hierarchy of absorption troughs under sublevel filtrations. From these summaries we define three interpretable descriptors: the trough line density $\lambda(t_\star)$, the total squared persistence $M_2=\sum_{j\in I_{\rm long}}\tau_j^2$, and the Betti-curve asymmetry $A_{\rm skew}$. In a Fisher forecast around a fiducial WDM model, $\lambda(t_\star)$ and $A_{\rm skew}$ provide strong local leverage on the heating axis, while $M_2$ retains appreciable sensitivity to the free-streaming scale and supplies an inclined constraint direction that reduces the remaining degeneracy in the $(f_X,m_{\rm WDM})$ plane. We further demonstrate that, under an SKA1-Low-like uncorrelated thermal-noise model, noise predominantly produces short-lived fluctuations that are removed by a uniform persistence cut, leaving the topology of long-lived troughs and the gross Betti-curve morphology largely intact. These results establish persistence-based descriptors as a robust non-Gaussian probe of small-scale structure and heating during Cosmic Dawn, naturally complementing power-spectrum and wavelet-based analyses. - oai:arXiv.org:2511.13092v2 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/publicdomain/zero/1.0/ - Hayato Shimabukuro - - - On the center-to-limb variations of the He I 10 830 \AA\ triplet - https://arxiv.org/abs/2511.14331 - arXiv:2511.14331v2 Announce Type: replace -Abstract: We present high-resolution spectroscopic observations of the quiet-Sun center-to-limb variations (CLV) of the He I triplet at 10 830 {\AA} and the nearby Si I 10 827 {\AA} line, observed with GREGOR Infrared Spectrograph (GRIS) and the improved High-resolution Fast Imager (HiFI+). The observations cover the interval $\mu = [0.1,\, 1.0]$, where $\mu$ is the cosine of the heliocentric angle. At each $\mu$-position, the spectra are spatially averaged over 0.02 $\mu$, and the resulting CLVs are given both as these averaged data points and as smooth polynomial curves fitted across each wavelength point. The He I spectra were inverted using the HAnle and ZEeman Light (HAZEL) code, showing an increase in optical depth towards the limb and a reversed convective blueshift for the red component, while the blue component was entirely absent. In addition, we find a strong increase in the steepness of the He I CLV compared to that of the nearby continuum. The Si I showed a behavior more typical of photospheric lines, namely shallower CLV, a reduction in width and depth, and a more typical convective blueshift. - oai:arXiv.org:2511.14331v2 - astro-ph.SR - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1051/0004-6361/202557267 - A&A 705, A116 (2026) - A. G. M. Pietrow, C. Kuckein, M. Verma, C. Denker, J. C. Trelles Arjona, R. Kamlah, K. Poppenh\"ager - - - Classical Cepheids in the Galactic thin disk I. Abundance gradients via non-local thermodynamic equilibrium spectral analysis - https://arxiv.org/abs/2511.22491 - arXiv:2511.22491v2 Announce Type: replace -Abstract: Classical Cepheids (CCs) have long been considered excellent tracers of the chemical evolution of the Milky Way's young disk. We present a homogeneous, NLTE spectroscopic analysis of 401 Galactic CCs, based on 1,351 high-resolution optical spectra, spanning Galactocentric distances from 4.6 to 29.3 kpc. Using PySME with MARCS atmospheres and state-of-the-art grids of NLTE departure coefficients, we derive atmospheric parameters and abundances for key species tracing multiple nucleosynthetic channels. Our sample-the largest CC NLTE dataset to date-achieves high internal precision and enables robust modeling of present-day thin-disk abundance patterns and radial gradients. We estimate abundance gradients using three analytic prescriptions (linear, logarithmic, bilinear with a break) within a Bayesian, outlier-robust framework, and we also apply Gaussian Process Regression to capture non-parametric variations. We find that NLTE atmospheric parameters differ systematically from LTE determinations. Moreover, iron and most elemental abundance profiles are better described by non-linear behavior rather than by single-slope linear models: logarithmic fits generally outperform simple linear models, while bilinear fits yield inconsistent break radii across elements. Gaussian Process models reveal a consistent outer-disk flattening of [X/H] for nearly all studied elements. The [X/Fe] ratios are largely flat with Galactocentric radius, indicating coherent chemical scaling with iron across the thin disk, with modest positive offsets for Na and Al and mild declines for Mn and Cu. Comparison with recent literature shows overall agreement but highlights NLTE-driven differences, especially in outer-disk abundances. These results provide tighter empirical constraints for chemo-dynamical models of the Milky Way and set the stage for future NLTE mapping with upcoming large spectroscopic surveys. - oai:arXiv.org:2511.22491v2 - astro-ph.GA - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Antonino Nunnari, Valentina D'Orazi, Giuliana Fiorentino, Vittorio F. Braga, Giuseppe Bono, Michele Fabrizio, Henrik J\"onsson, Rolf-Peter Kudritzki, Ronaldo da Silva, Maria Bergemann, Eloisa Poggio, Jonah M. Otto, Karina Baeza-Villagra, Angela Bragaglia, Giulia Ceci, Massimo Dall'Ora, Laura Inno, Carmela Lardo, Noriyuki Matsunaga, Matteo Monelli, Manuel S\'anchez-Benavente, Chris Sneden, Maria Tantalo, Fr\'ed\'eric Th\'ev\'enin, Marcella Di Criscienzo, Gamze B\"ocek Topcu - - - Pre-supernova O-C shell mergers could produce more $^{44}\mathrm{Ti}$ than the explosion - https://arxiv.org/abs/2512.17705 - arXiv:2512.17705v4 Announce Type: replace -Abstract: The formation of $^{44}\mathrm{Ti}$ in massive stars is thought to occur during explosive nucleosynthesis, however recent studies have shown it can be produced during O-C shell mergers prior to core collapse. We investigate how mixing according to 3D macro physics derived from hydrodynamic simulations impacts the pre-supernova O-C shell merger nucleosynthesis and if it can dominate the explosive supernova production of $^{44}\mathrm{Ti}$ and other radioactive isotopes. We compare a range of observations and models of explosive $^{44}\mathrm{Ti}$ yields to pre-explosive multi-zone mixing-burning nucleosynthesis simulations of an O-C shell merger in a $15~\mathrm{M}_\odot$ stellar model with mixing conditions corresponding to different 3D hydro mixing scenarios. Radioactive species produced in the O shell have a spread in their pre-explosive yields predictions across different 3D mixing scenarios of 2.14 dex on average. $^{44}\mathrm{Ti}$ has the largest spread of 4.78 dex. The pre-explosive production of $^{44}\mathrm{Ti}$ can be larger than the production of all massive star models in the NuGrid data set where $^{44}\mathrm{Ti}$ is dominated by the explosive nucleosynthesis contribution, as well all other massive star and supernova models. We conclude that quantitative predictions of $^{44}\mathrm{Ti}$ and other radioactive species more broadly require an understanding of the 3D hydrodynamic mixing conditions present during the O-C shell merger. - oai:arXiv.org:2512.17705v4 - astro-ph.SR - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Joshua Issa, Falk Herwig - - - Red noise-based false alarm thresholds for astrophysical periodograms via Whittle's approximation to the likelihood - https://arxiv.org/abs/2512.18205 - arXiv:2512.18205v2 Announce Type: replace -Abstract: Astronomers who search for periodic signals using Lomb-Scargle periodograms rely on false alarm level (FAL) estimates to identify statistically significant peaks. Although FALs are often calculated from white noise models, many astronomical time series suffer from red noise. Prewhitening is a statistical technique in which a continuum model is subtracted from log power spectrum estimate, after which the observer can proceed with a white-noise treatment. Here we present a prewhitening-based method of calculating frequency-dependent FALs. We fit power laws and autoregressive models of order 1 to each Lomb-Scargle periodogram by minimizing the Whittle approximation to the negative log-likelihood (NLL), then calculate FALs based on the best-fit model power spectrum. Our technique is a novel extension of the Whittle NLL to datasets with uneven time sampling. We demonstrate FAL calculations using observations of $\alpha$~Cen~B, GJ~581, HD 192310, synthetic data from the radial velocity (RV) Fitting Challenge, and {\it Kepler} observations of a differential rotator. The {\it Kepler} data analysis shows that only true rotation signals are detected by red-noise FALs, while white-noise FALs suggest all spurious peaks in the low-frequency range are significant. A high-frequency sinusoid injected into $\alpha$~Cen~B $\log R^{\prime}_{HK}$ observations exceeds the 1\% red-noise FAL despite having only 8.9\% of the power of the dominant rotation signal. In a periodogram of HD 192310 RVs, peaks associated with differential rotation and planets are detected against the 5\% red-noise FAL without iterative model fitting or subtraction. Software for calculating red noise-based FALs is available on GitHub. - oai:arXiv.org:2512.18205v2 - astro-ph.IM - astro-ph.EP - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Amna Ejaz, Sarah Dodson-Robinson, Charlotte Haley - - - Abundance of cosmic voids in EFT of dark energy - https://arxiv.org/abs/2512.20171 - arXiv:2512.20171v2 Announce Type: replace -Abstract: Cosmic voids in the large-scale structure are among the useful probes for testing gravity on cosmological scales. In this paper, we investigate the evolution of voids in the Horndeski theory using the effective field theory (EFT) of dark energy. Modeling the void formation with the dynamics of spherical mass shells, we study how modifications of gravity encoded into the EFT of dark energy change the linearly extrapolated critical density contrast that is relevant for the criterion for void formation, with particular focus on the time-dependent parameter characterizing the effect of kinetic braiding. It is found that the change in the critical density contrast is one order of magnitude smaller than the dimensionless EFT parameter because of a slight imbalance between two compensating effects. We then compute the void abundance using the Sheth--van de Weygaert void size function and demonstrate that it exhibits scale-dependent modifications. It is shown that the modifications to the void size function on small scales are almost entirely determined by the modified linear matter power spectrum, while the modifications on large scales are dominated by the contributions from the linear matter spectrum and the critical density contrast. - oai:arXiv.org:2512.20171v2 - astro-ph.CO - gr-qc - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Toshiki Takadera, Shin'ichi Hirano, Tsutomu Kobayashi - - - Testing supermassive primordial black holes with lensing signals of binary black hole merges - https://arxiv.org/abs/2601.01034 - arXiv:2601.01034v2 Announce Type: replace -Abstract: Next-generation ground-based gravitational wave (GW) detectors are expected to observe millions of binary black hole mergers, a fraction of which will be strongly lensed by intervening galaxies or clusters, producing multiple images with characteristic distribution of time delay. Importantly, the predicted rate and properties of such events are sensitive to the abundance and distribution of strong lensing objects which directly depends on cosmological models. One such scenario posits the existence of supermassive primordial black holes (SMPBHs) in the early universe, which would enhance the formation of dark matter halos. This mechanism has been proposed to explain the abundance of high-redshift galaxies observed by James Webb Space Telescope. Crucially, the same cosmological model with SMPBHs would also leave a distinct imprint on the population of strongly lensed GWs. It predicts both an increased event rate and a modified distribution of time delays between the multiple images. Therefore, we propose statistical measurements of the rate and time delay distribution of strong lensing GW events as a powerful probe to directly constrain the abundance of SMPBHs. Considering $\Lambda$CDM cosmology with (non-)clustered SMPBHs, we find that the abundance of SMPBHs $f_{\rm PBH}$ with masses above $10^8~M_{\odot}$ is constrained to be $\sim10^{-4}$ at $95\%$ confidence level. It will be comparable and complementary to the currently available constraint from large scale structure observations. - oai:arXiv.org:2601.01034v2 - astro-ph.CO - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Huan Zhou, Bin Liu, Zheng-Xiang Li, Xi-Jing Wang, Kai Liao - - - Decoding Cygnus X-2: The Critical Role of Reflection in IXPE Data - https://arxiv.org/abs/2601.01669 - arXiv:2601.01669v3 Announce Type: replace -Abstract: We present a spectro-polarimetric re-analysis of the first IXPE observation of Cygnus X-2 which we determine to be mainly in the normal branch, from quasi-simultaneous observations with NuSTAR, NICER, and INTEGRAL. We measure the hard X-ray polarization angle and find it to be consistent with the previously measured position angle of the radio jet. Leveraging NuSTAR's detection of both the relativistic Fe K emission line and the Compton hump, we constrain the flux contribution of the reflected emission from the inner accretion disk to be 10% of the total X-ray flux in the IXPE energy band. Unlike previous studies that modeled only the Fe K emission line, we fit the full-band reflection spectrum using a fully relativistic disk model. There is strong degeneracy between the Comptonized and reflection components. Given that the Comptonized component is not expected to be highly polarized, a polarization degree of approximately 20% for the reflection component could explain the X-ray polarization data from IXPE. We also discuss the disk inclination angle inferred from our spectro-polarimetric modeling, as well as other possible explanations for the data. - oai:arXiv.org:2601.01669v3 - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1016/j.jheap.2026.100548 - Journal of High Energy Astrophysics, (2026), 51, 100548 - Honghui Liu, Jiachen Jiang, Adam Ingram, Cosimo Bambi, Andrew C. Fabian, Ruben Farinelli, Renee Ludlam, Nathalie Degenaar, Jakub Podgorny, Andrea Santangelo, James F. Steiner, Andrew J. Young, Zuobin Zhang - - - A Tale of Two Dust Disks in Our Milky Way - https://arxiv.org/abs/2601.02724 - arXiv:2601.02724v2 Announce Type: replace -Abstract: Cosmic dust plays a vital role in stellar and galactic formation and evolution, but its three-dimensional structure in the Milky Way has remained unclear due to insufficient precise reddening and distance measurements. Although early studies typically adopted a single-disk model, we detect two distinct components at Galactocentric distances of 5-14 kpc, enabled by photometric, spectroscopic, and astrometric measurements of over 5 million stars. The thin dust disk's scale height increases radially from 60 to 200 pc, while the thick disk grows from 300 to 800 pc. For the first time, we find the thin and thick dust disk correlates spatially with molecular and atomic hydrogen disk, respectively. The thin, thick, and combined disks have scale lengths of 9.6+1.2-1.1 kpc, 4.2+0.4-0.3 kpc, and 6.6+0.3-0.3 kpc, respectively. The gas-to-dust ratio shows an exponential radial gradient, increasing from around 60 at 5 kpc to around 470 at 14 kpc. These findings provide new insights into dust morphology in the Galaxy and raise fundamental questions that require further investigation. - oai:arXiv.org:2601.02724v2 - astro-ph.GA - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Ruoyi Zhang, Haibo Yuan, Bingqiu Chen, Maosheng Xiang, Yang Huang, Xiaowei Liu, Jifeng Liu - - - Late-Time Infrared Cooling in Magnetar-Driven Supernovae - https://arxiv.org/abs/2601.03373 - arXiv:2601.03373v2 Announce Type: replace -Abstract: A central magnetar engine is commonly invoked to explain energetic supernovae, which should have multiple signals in multiwavelength emission. Photoionization from the pulsar wind nebula (PWN) can create distinct spectroscopic signals in the nebular phase. Recent models suggest infrared emission, particularly from Ne II, can be prominent at late times. This work examines the cooling power of optical and infrared transitions to determine which lines contribute strongly to cooling and on what timescale. The models show infrared cooling becomes strong at $\sim$ 3 years post-explosion and dominates by 6 years, with [Ne II] 12.8$\mu$m being the strongest coolant. The fraction of total cooling in the infrared increases sharply once the PWN luminosity decreases below 10$^{40}$ erg s$^{-1}$, and this fraction also increases with increasing ejecta mass and decreasing average PWN photon energy. However, the emission from [Ne II] 12.8$\mu$m increases with increasing PWN luminosity and increasing ejecta mass. Cooling at 1 year is dominated by optical O and S lines, with infrared Ar, Ni, and Ne lines becoming strong at 3 years. Optical cooling is almost negligible at 6 years, with the supernova cooling almost entirely through mid- and far-infrared transitions. JWST spectroscopy with MIRI should be able to detect these lines out to $z \sim 0.1$. Supernovae with higher magnetic fields transition to infrared cooling on earlier timescales, while infrared-dominated supernovae should have strong emission from neutral atoms and emit strongly in radio at sub-decade timescales. - oai:arXiv.org:2601.03373v2 - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Conor M. B. Omand - - - Limit cycles and the climate history of Mars - https://arxiv.org/abs/2601.07159 - arXiv:2601.07159v2 Announce Type: replace -Abstract: Evidence for fluvial features and standing liquid water indicate that Mars was a warmer and wetter place in its past; however, climate models have historically been unable to produce conditions to yield a warm early Mars under the faint young sun. Some models invoke thick greenhouse atmospheres to produce continuously warm conditions, but others have argued that available geologic evidence is more consistent with short-duration and transient warming events on an otherwise cold Mars. One possibility of harmonizing these perspectives is that early Mars experienced climate limit cycles that caused the climate to oscillate between short periods of warmth and prolonged periods of glaciation, due to modulation of greenhouse warming by the carbonate-silicate cycle. This study suggests that episodic limit cycling during the Noachian and Hesperian periods provides a hypothetical explanation for the timing and formation of fluvial features on Mars. A schematic time-forward trajectory of the full history of Mars is calculated using an energy balance climate model, which includes an active carbonate-silicate cycle, instellation changes due to the sun's main sequence evolution, variations in the obliquity of Mars, and supplemental warming from additional greenhouse gases beyond carbon dioxide alone. These calculations demonstrate the viability of a climate history for Mars involving episodic limit cycling to enable the formation of the valley networks at 4.1-3.5 Ga and delta features at 3.3-3.0 Ga, interspersed with cold stable climates and ending in the late Amazonian in a carbon dioxide condensation regime. This schematic climate trajectory provides a plausible narrative that remains consistent with available geologic data, and further exploration of warming mechanisms for the climate of Mars should consider the possibility of episodic transient events driven by carbonate-silicate limit cycling. - oai:arXiv.org:2601.07159v2 - astro-ph.EP - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1016/j.icarus.2026.116945 - Jacob Haqq-Misra - - - An eclipsing 8.56 minute orbital period mass-transferring binary - https://arxiv.org/abs/2601.07925 - arXiv:2601.07925v2 Announce Type: replace -Abstract: We report the discovery of ATLAS J101342.5-451646.8 (hereafter ATLAS J1013-4516), an eclipsing, mass-transferring AM Canum Venaticorum binary with an 8.56-minute orbital period, identified via periodic variability in light curves from the Asteroid Terrestrial-impact Last Alert System survey of Gaia white dwarf candidates. Follow-up spectroscopy with the Large Lenslet Array Magellan Spectrograph reveals a helium-dominated accretion disk, while high-speed photometry with ULTRACAM shows pronounced primary and secondary eclipses. We construct a decade-long timing baseline using data from ATLAS, Gaia, ULTRACAM on the New Technology Telescope, and the proto-Lightspeed instrument on the Magellan Clay telescope. From this baseline, we measure an orbital period derivative of dP/dt = -1.60 +/- 0.07 x 10^-12 seconds per second. Interpreted in the context of stable mass transfer, the magnitude and sign of the period derivative indicate that the orbital evolution is governed by the interplay between gravitational-wave-driven angular momentum losses and mass transfer, directly probing the donor star's structural response to mass loss. Assuming angular momentum loss dominated by gravitational wave emission, we constrain the component masses and infer the characteristic gravitational wave strain of the system for future space-based observatories such as the Laser Interferometer Space Antenna. We predict a characteristic strain corresponding to a four-year signal-to-noise ratio greater than approximately 20, establishing ATLAS J1013-4516 as a strong prospective source for probing long-term orbital evolution in the mass-transferring regime. - oai:arXiv.org:2601.07925v2 - astro-ph.SR - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Emma T. Chickles (Massachusetts Institute of Technology, Cambridge, USA), Joheen Chakraborty (Massachusetts Institute of Technology, Cambridge, USA), Kevin B. Burdge (Massachusetts Institute of Technology, Cambridge, USA), Vik S. Dhillon (University of Sheffield, Sheffield, UK, Instituto de Astrofisica de Canarias, La Laguna, Spain), Paul Draghis (Massachusetts Institute of Technology, Cambridge, USA), Kareem El-Badry (California Institute of Technology, Pasadena, USA), Matthew J. Green (Max Planck Institute for Astronomy, Heidelberg, Germany), Aaron Householder (Massachusetts Institute of Technology, Cambridge, USA), Sarah Hughes (Massachusetts Institute of Technology, Cambridge, USA), Christopher Layden (Massachusetts Institute of Technology, Cambridge, USA), Stuart P. Littlefair (University of Sheffield, Sheffield, UK), James Munday (University of Warwick, Coventry, UK), Ingrid Pelisoli (University of Warwick, Coventry, UK), Maya S. Redden (Stanford University, Stanford, USA), John Tonry (University of Hawaii, Honolulu, USA), Jan van Roestel (Institute of Science and Technology Austria, Klosterneuburg, Austria, University of Amsterdam, Amsterdam, The Netherlands), F. Elio Angile (Massachusetts Institute of Technology, Cambridge, USA), Alex J. Brown (University of Hamburg, Hamburg, Germany), Noel Castro (University of Warwick, Coventry, UK), Jack Dinsmore (Stanford University, Stanford, USA), Martin Dyer (University of Sheffield, Sheffield, UK, Research Software Engineering, University of Sheffield, Sheffield, UK), Gabor Furesz (Massachusetts Institute of Technology, Cambridge, USA), Michelle Gabutti (Massachusetts Institute of Technology, Cambridge, USA), James Garbutt (University of Sheffield, Sheffield, UK), Daniel Jarvis (University of Sheffield, Sheffield, UK), Mark R. Kennedy (University College Cork, Cork, Ireland), Paul Kerry (University of Sheffield, Sheffield, UK), James McCormac (University of Warwick, Coventry, UK), Geoffrey Mo (California Institute of Technology, Pasadena, USA, Carnegie Observatories, Pasadena, USA), Dave Osip (Las Campanas Observatory, La Serena, Chile), Steven Parsons (University of Sheffield, Sheffield, UK), Eleanor Pike (University of Sheffield, Sheffield, UK), Jack Piotrowski (Carnegie Observatories, Pasadena, USA), Roger W. Romani (Stanford University, Stanford, USA), David Sahman (University of Sheffield, Sheffield, UK), Rob Simcoe (Massachusetts Institute of Technology, Cambridge, USA) - - - Upper limits on microhertz gravitational waves from supermassive black-hole binaries using PSR J1909-3744 data from the second IPTA data release - https://arxiv.org/abs/2601.09054 - arXiv:2601.09054v2 Announce Type: replace -Abstract: We present the results of a search for gravitational waves (GWs) from individual sources using high-cadence observations of PSR J1909\(-\)3744 obtained during an intensive observing campaign with the International Pulsar Timing Array second data release (IPTA-DR2) between July 2010 and November 2012. The observations, conducted at three different radio frequencies with the Nan\c{c}ay Radio Telescope (NRT) and Parkes Telescope (PKS) and five frequencies with the Green Bank Telescope (GBT), enabled precise corrections for dispersion measure effects and scattering variations. After these corrections, the timing residuals showed an unmodeled periodic noise component with an amplitude of 340 ns. Our analysis yields upper limits on the GW strain from individual sources, constraining it to be below \(1.9 \times 10^{-14}\) at 71 nHz and \(2.3 \times 10^{-13}\) at 1 \textmu Hz for average sky locations, while for optimal source locations the limits improve to \(6.2 \times 10^{-15}\) and \(8.9 \times 10^{-14}\) at the same frequencies, respectively. Our new limits are about a factor of 1.52 more stringent than those of Perera et al. based on an earlier EPTA data. - oai:arXiv.org:2601.09054v2 - astro-ph.HE - gr-qc - Fri, 16 Jan 2026 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jing Zou, Jingbo Wang Jianping Yuan, De Zhao, Yirong Wen, Wei Li, Na Wang, Yong Xia - - - Probing Spin-2 Ultralight Dark Matter with Space-based Gravitational Wave Detectors in the mHz Regime - https://arxiv.org/abs/2501.11071 - arXiv:2501.11071v2 Announce Type: replace-cross -Abstract: Spin-2 ultralight dark matter (ULDM) is a viable dark matter candidate and it can be constrained using gravitational wave (GW) observations. In this paper, we investigate the detectability of spin-2 ULDM by space-based GW interferometers. By considering a direct coupling between spin-2 ULDM and ordinary matter, we derive the corresponding response functions and sensitivity curves for various time-delay interferometry channels and calculate the optimal sensitivity curves for future millihertz GW detectors. Our results demonstrate that the space-based detectors can place stringent constraints on the coupling constant of spin-2 ULDM, reaching $\alpha \sim 10^{-10}$ around a mass of $m \sim 10^{-17} \rm eV$, surpassing current limits from ground-based detectors and pulsar timing arrays. Thus, the space-based GW detectors can serve as powerful tools not only for detecting GWs but also for probing fundamental properties of ultralight dark matter. - oai:arXiv.org:2501.11071v2 - gr-qc - astro-ph.CO - hep-ph - Fri, 16 Jan 2026 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1103/cz2w-5cfj - Physical Review D 112, 064030 (2025) - Jing-Rui Zhang, Ju Chen, Heng-Sen Jiao, Rong-Gen Cai, Yun-Long Zhang - - - Non-perturbative determination of the sphaleron rate for first-order phase transitions - https://arxiv.org/abs/2506.04939 - arXiv:2506.04939v2 Announce Type: replace-cross -Abstract: In many extensions of the Standard Model electroweak phase transitions at high temperatures can be described in a minimal dimensionally reduced effective theory with SU(2) gauge field and fundamental Higgs scalar. In this effective theory, all thermodynamic information is governed by two dimensionless ratios $x \equiv \lambda_3/g^2_3$ and $y\equiv m^2_3/g^4_3$, where $\lambda_3$, $m^2_3$ and $g_3$ are the effective thermal scalar self-interaction coupling, the thermal mass and the effective gauge-coupling, respectively. By using non-perturbative lattice simulations to determine the rate of sphaleron transitions in the entire $(x,y)$-plane corresponding to the Higgs phase, and by applying previous lattice results for the bubble nucleation, we find a condition $x(T_c) \lesssim 0.025$ to guarantee preservation of the baryon asymmetry, which translates to $v/T_c \equiv \sqrt{2 \Delta \langle \phi^\dagger \phi \rangle}/T_c \gtrsim 1.33$ for the (gauge-invariant) discontinuity in Higgs condensate. This indicates that viability of the electroweak baryogenesis requires the phase transition to be slightly stronger than previously anticipated. Finally, we present a general template for analysing such viability in a wide class of beyond the Standard Model theories, in which new fields are heavy enough to be integrated out at high temperature. - oai:arXiv.org:2506.04939v2 - hep-ph - astro-ph.CO - hep-lat - Fri, 16 Jan 2026 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - 10.1103/q1jq-gq9m - Phys. Rev. D 113, 016014, (2026) - Jaakko Annala, Kari Rummukainen, Tuomas V. I. Tenkanen - - - Superconducting Ring Resonators: Modelling, Simulation, and Experimental Characterisation - https://arxiv.org/abs/2506.23811 - arXiv:2506.23811v2 Announce Type: replace-cross -Abstract: We present a theoretical and experimental study of superconducting ring resonators as an initial step toward their implementation in superconducting electronics and quantum technologies, with promising applications including superconducting parametric amplifiers with pump-signal isolation, flux-controlled quantum circuits, ultra-sensitive measurements in quantum sensing, and THz instrumentations. These devices have the potentially valuable property of supporting two orthogonal electromagnetic modes that couple to a common Cooper pair, quasiparticle, and phonon system. We present here a comprehensive theoretical and experimental analysis of the superconducting ring resonator system. We have developed superconducting ring resonator models that describe the key features of microwave behaviour to first order, providing insights into how transmission line inhomogeneities give rise to frequency splitting and mode rotation. Furthermore, we constructed signal flow graphs for a four-port ring resonator to numerically validate the behaviour predicted by our theoretical analysis. Superconducting ring resonators were fabricated in both coplanar waveguide and microstrip geometries using Al and Nb thin films. Microwave characterisation of these devices demonstrates close agreement with theoretical predictions. Our study reveals that frequency splitting and mode rotation are prevalent in ring systems with coupled degenerate modes, and these phenomena become distinctly resolved in high quality factor superconducting ring resonators. - oai:arXiv.org:2506.23811v2 - cond-mat.supr-con - astro-ph.IM - Fri, 16 Jan 2026 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1088/1361-6668/ae06cb - Superconductor Science and Technology, 38 (2025) 095012 - Zhenyuan Sun, Stafford Withington, Christopher Thomas, Songyuan Zhao - - - $\mathbb Z_2$-Stable Dark Matter via Broken $\text{SU}(5)$ Gauge Bosons - https://arxiv.org/abs/2511.19462 - arXiv:2511.19462v4 Announce Type: replace-cross -Abstract: I construct and analyze a dark matter sector that is neutral under the unbroken Standard Model gauge group and couples only to the broken $\text{SU}(5)$ gauge directions, the leptoquark vectors $X,Y$. An exact $\mathbb Z_2$ renders the dark matter stable. I give a gauge-covariant definition of projectors onto the unbroken Standard Model and broken ($X,Y$) subspaces, demonstrate that the covariant derivative of dark matter selects only $X,Y$, and integrate out $X,Y$ at tree level to obtain the leading effective operators. I also derive the loop-induced $\chi^2\,G^a_{\mu\nu}G^{a\mu\nu}$ coupling to gluons, prove color neutrality, and show consistency with cold dark matter phenomenology. Cosmological production proceeds via UV freeze-in or even more suppressed channels in. - oai:arXiv.org:2511.19462v4 - hep-ph - astro-ph.CO - gr-qc - hep-th - Fri, 16 Jan 2026 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - E. J. Thompson - - - An Excited Dark Matter Solution to the MeV Galactic Center Excesses - https://arxiv.org/abs/2512.13797 - arXiv:2512.13797v2 Announce Type: replace-cross -Abstract: Recent COMPTEL data analysis reveals a $\sim$ 2 MeV continuum excess whose spatial distribution closely matches the long-standing 511 keV line observed by INTEGRAL/SPI, indicating a common population of low-energy positrons that is difficult to reconcile with known astrophysical sources or standard thermal dark matter (DM). We show that a minimal Excited Dark Matter (XDM) model naturally explains these features. In this scenario a DM particle $\chi$ is inelastically upscattered into an excited state $\chi^*$, followed by de-excitation $\chi^*\to\chi e^+ e^-$ producing $\sim$2 MeV positrons that reproduce the 511 keV line morphology and the COMPTEL MeV continuum. Using a full cosmic-ray (CR) propagation treatment, we obtain an excellent fit for $m_\chi\simeq$ 1.5 TeV DM particle with mass-splitting $\Delta m =m_{\chi^*}-m_\chi \simeq$ 4 MeV for an inelastic geometric scattering cross section of $\sigma_\textrm{mr}= 3-4\times 10^{-23}\,\textrm{cm}^2$. The same positrons supply a substantial, radially flat contribution to the anomalous Central Molecular Zone (CMZ) ionization rate. This is the first unified treatment of XDM-induced positrons across all three observables, yielding correlated MeV signatures testable by upcoming missions targeting the Galactic MeV band. - oai:arXiv.org:2512.13797v2 - hep-ph - astro-ph.HE - Fri, 16 Jan 2026 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Shyam Balaji, Damon Cleaver, Pedro De la Torre Luque - - - Towards a unified quantum field theory of dark energy and inflation: unstable de Sitter vacuum and running vacuum - https://arxiv.org/abs/2601.05218 - arXiv:2601.05218v2 Announce Type: replace-cross -Abstract: Inflation is a necessary cosmic mechanism to cure basic inconsistencies of the standard model of cosmology. These problems are usually `fixed' by postulating the existence of a scalar field (called the ``inflaton''). However, other less ad hoc options are possible. In the running vacuum model (RVM) framework, the vacuum energy density (VED) is a function of the Hubble rate $H$ and its time derivatives: $\rho_{\rm vac}=\rho_{\rm vac}(H, \dot{H},\ddot{H},\dots)$. In this context, the VED is dynamical (there is no rigid cosmological constant $\Lambda$). In the FLRW epoch, $\rho_{\rm vac}$ evolves very slowly with expansion, as befits the observed $\Lambda\simeq$const. behavior. In contrast, in the very early universe the vacuum fluctuations induce higher powers $H^N$ capable of unleashing fast inflation in a short period in which $H\simeq$ const. We call this mechanism `RVM-inflation'. It does not require an inflaton field since inflation is brought about by pure quantum field theory (QFT) effects on the dynamical background. It is different from Starobinsky's inflation, in which $H$ is never constant. In this work, we study a closely related scenario: the decay of the exact de Sitter vacuum into FLRW spacetime in its radiation epoch and the subsequent impact on the current universe, and compare with the RVM. We find that in both cases inflation is driven by $H^4$ powers together with subleading contributions of order $H^2$ that ease a graceful-exit transition into the radiation-dominated epoch, where the FLRW regime starts and ultimately develops a mildly evolving VED in the late universe: $\delta\rho_{\rm vac}\sim {\cal O}(m_{\rm Pl} ^2 H^2)$. The net outcome is an unified QFT approach to inflation and dark energy (conceived as dynamical vacuum energy) with potentially measurable phenomenological consequences in the present universe which can help cure the cosmological tensions. - oai:arXiv.org:2601.05218v2 - gr-qc - astro-ph.CO - hep-ph - hep-th - Fri, 16 Jan 2026 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Joan Sol\`a Peracaula, \`Alex Gonz\'alez-Fuentes, Cristian Moreno-Pulido -