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We present high-resolution CO(1-0) and CO(2-1) maps of the LINER 2 galaxy NGC1961. This galaxy is unusual among late-type (Sc) disk galaxies in having a very large radial extent and inferred dynamical mass. |
In this paper, we study small-scale fluctuations (baryon pressure sound waves) in the baryon fluid during recombination. In particular, we look at their evolution in the presence of relative velocities between baryons and photons on large scales ($k \sim 10^{-1} \ {\rm Mpc}^{-1}$), which are naturally present during t... |
We explore the self-regulation of star formation using a large suite of high resolution hydrodynamic simulations, focusing on molecule-dominated regions (galactic centers and [U]LIRGS) where feedback from star formation drives highly supersonic turbulence. In equilibrium the total midplane pressure, dominated by turbu... |
We consider a model of the early universe which consists of two scalar fields: the inflaton, and a second field which drives the stabilisation of the Planck mass (or gravitational constant). We show that the non-minimal coupling of this second field to the Ricci scalar sources a non-adiabatic pressure perturbation. |
In this paper, we consider a scenario of spontaneous baryogenesis in a framework of warm quintessential inflation where the residual inflaton field, left out after warm inflation, plays the role of quintessence field at late times and is coupled to a non-conserved baryonic current. Assuming a four fermion $(B-L)$ viol... |
We present galaxy cluster mass-richness relations found in the Sloan Digital Sky Survey Stripe 82 co-add using clusters found using a Voronoi tessellation cluster finder. These relations were found using stacked weak lensing shear observed in a large sample of galaxy clusters. |
[Abridged] We present an analysis of optical spectroscopically-identified AGN to M*+1 in a sample of 6 self-similar SDSS galaxy clusters at z=0.07. These clusters are specifically selected to lack significant substructure at bright limits in their central regions so that we are largely able to eliminate the local acti... |
We demonstrate that the perturbations of strongly lensed images by low-mass dark matter subhalos are significantly impacted by the concentration of the perturbing subhalo. For subhalo concentrations expected in $\Lambda$CDM, significant constraints on the concentration can be obtained at HST resolution for subhalos wi... |
We present an analysis of high-quality X-ray data out to the virial radius for the two galaxy clusters Abell 1246 and GMBCG J255.34805+64.23661 (J255) by means of our entropy-based SuperModel. For Abell 1246 we find that the spherically-averaged entropy profile of the intracluster medium (ICM) progressively flattens o... |
We study the origin of the extragalactic diffuse gamma-ray background using the data from the Fermi telescope. To estimate the background level, we count photons at high Galactic latitudes |b|>60 degrees. |
Projection effects, whereby galaxies along the line-of-sight to a galaxy cluster are mistakenly associated with the cluster halo, present a significant challenge for optical cluster cosmology. We use statistically representative spectral coverage of luminous galaxies to investigate how projection effects impact the lo... |
We present results for X-ray point sources in the Sc galaxy NGC 2276, obtained by analyzing Chandra data. The galaxy is known to be very active in many wavelengths, possibly due to gravitational interaction with the central elliptical of the group, NGC 2300. |
Cosmicflows-3 distances and inferred peculiar velocities of galaxies have permitted the reconstruction of the structure of over and under densities within the volume extending to 0.05c. This study focuses on the under dense regions, particularly the Local Void that lies largely in the zone of obscuration and consequen... |
We use absolutely calibrated data between 3 and 90 GHz from the 2006 balloon flight of the ARCADE 2 instrument, along with previous measurements at other frequencies, to constrain models of extragalactic emission. Such emission is a combination of the Cosmic Microwave Background (CMB) monopole, Galactic foreground emi... |
We investigate the impact of astrophysical systematics on cosmic shear cosmological parameter constraints from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS), and the concordance with cosmic microwave background measurements by Planck. We present updated CFHTLenS cosmic shear tomography measurements exte... |
The recently introduced discrete persistent structure extractor (DisPerSE, Soubie 2010, paper I) is implemented on realistic 3D cosmological simulations and observed redshift catalogues (SDSS); it is found that DisPerSE traces equally well the observed filaments, walls, and voids in both cases. In either setting, fila... |
We present the review of some new problems in cosmology and physics of stars in connection with future launching of WSO. We discuss three problems. |
Upcoming ground and space-based experiments may have sufficient accuracy to place significant constraints upon high-redshift star formation, Reionization, and dark matter (DM) using the global 21-cm signal of the intergalactic medium. In the early universe, when the relative abundance of low-mass DM halos is important... |
In classical cosmological analysis of large scale structure surveys with 2-pt functions, the parameter measurement precision is limited by several key degeneracies within the cosmology and astrophysics sectors. For cosmic shear, clustering amplitude $\sigma_8$ and matter density $\Omega_m$ roughly follow the $S_8=\sig... |
In `A Bayesian Approach to Locating the Red Giant Branch Tip Magnitude (PART I),' a new technique was introduced for obtaining distances using the TRGB standard candle. Here we describe a useful complement to the technique with the potential to further reduce the uncertainty in our distance measurements by incorpo... |
Recent high-resolution cosmological hydrodynamic simulations run with a variety of codes systematically predict large amounts of entropy in the intra-cluster medium at low redshift, leading to flat entropy profiles and a suppressed cool-core population. This prediction is at odds with X-ray observations of groups and ... |
To improve the performance of full-shape analyses of large-scale structure, we consider using a halo occupation distribution (HOD)-informed prior for the effective field theory (EFT) nuisance parameters. We generate 320 000 mock galaxy catalogs using 10 000 sets of HOD parameters across 32 simulation boxes with differ... |
The existence of a primordial stochastic gravitational wave background (SGWB) is a common prediction in various models of the early Universe. Despite constraints at different frequency ranges and claims of detection in the nHz range by Pulsar Timing Arrays, the amplitude and spectral dependence of the SGWB in the mHz ... |
We use the most recent type Ia supernovae (SNe Ia) observations to perform a statistical comparison between the standard $\Lambda$CDM model and its extensions [$w$CDM and $w(z)$CDM] and some alternative cosmologies: namely, the Dvali--Gabadadze--Porrati (DGP) model, a power-law $f(R)$ scenario in the metric formalism a... |
Does the void environment have a sizable effect on the evolution of dwarf galaxies? If yes, the best probes should be the most fragile least massive dwarfs. |
In this paper, we propose a Gaussian Process (GP) emulator for the calculation of a) tomographic weak lensing band-power spectra, and |
We study the mass accretion histories (MAHs) and density profiles of dark matter halos using N-body simulations of self-similar gravitational clustering from scale-free power spectra, $P(k)\propto k^n$. We pay particular attention to the density profile curvature, which we characterize using the shape parameter, $\alp... |
We discuss present and future cosmological constraints on variations of the fine structure constant $\alpha$ induced by an early dark energy component having the simplest allowed (linear) coupling to electromagnetism. We find that current cosmological data show no variation of the fine structure constant at recombinat... |
We study the observed correlation between atomic gas content and the likelihood of hosting a large scale bar in a sample of 2090 disc galaxies. Such a test has never been done before on this scale. |
Within the Cold Dark Matter scenario the hierarchical merging paradigm is the natural result to form massive galactic halos by the minor mergers of sub-halos and, by this, inherently their stellar halo. Although this must be also invoked for the Milky Way, the context of chemical and kinematic coherence of halo stars ... |
LIRGs and ULIRGs are much more numerous at higher redshifts than locally, dominating the star-formation rate density at redshifts ~1 - 2. Therefore, they are important objects in order to understand how galaxies form and evolve through cosmic time. |
Context: GRB afterglows are excellent probes of gas and dust in star-forming galaxies at all epochs. It has been posited that dust in the early Universe must be different from dust at lower z. |
The recently sharpened H_0 tension is argued not to be a result of data calibration or other systematic but an indication for the common nature of dark matter and dark energy. This conclusion is devised within modified weak-field General Relativity where the accelerated expansion of the Universe and the dynamics of ga... |
The gravitationally lensed Supernova Refsdal appeared in multiple images, produced through gravitational lensing by a massive foreground galaxy cluster. After the supernova appeared in 2014, lens models of the galaxy cluster predicted an additional image of the supernova would appear in 2015, which was subsequently ob... |
We present the first limits on the Epoch of Reionization (EoR) 21-cm HI power spectra, in the redshift range $z=7.9-10.6$, using the Low-Frequency Array (LOFAR) High-Band Antenna (HBA). In total 13\,h of data were used from observations centred on the North Celestial Pole (NCP). |
We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and thermal dust emission, derived from the third set of Planck frequency maps. These products have significantly lower contamination from instrumental systematic effects than previous versions. |
We study effects on the luminosity distance of a local inhomogeneity seeded by primordial curvature perturbations of the type predicted by the inflationary scenario and constrained by the cosmic microwave background radiation. We find that a local underdensity originated from a one, two or three standard deviations pe... |
We present multi-band photometry of 185 type-Ia supernovae (SN Ia), with over 11500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics (CfA). |
We use a large set of cosmological smoothed particle hydrodynamics (SPH) simulations to examine the effect of mass resolution and box size on synthetic Lya forest spectra at 2 \leq z \leq 5. The mass resolution requirements for the convergence of the mean Lya flux and flux power spectrum at z=5 are significantly stric... |
We perform SubHalo Abundance Matching (SHAM) studies on UNIT simulations with \{$\sigma, V_{\rm ceil}, v_{\rm smear}$\}-SHAM and \{$\sigma, V_{\rm ceil},f_{\rm sat}$\}-SHAM. They are designed to reproduce the clustering on 5--30$\,\hmpc$ of Luminous Red Galaxies (LRGs), Emission Line Galaxies (ELGs) and Quasi-Stellar ... |
Motivated by the desire to test modified gravity theories exhibiting the Vainshtein mechanism, we solve in various physically relevant limits, the retarded Galileon Green's function (for the cubic theory) about a background sourced by a massive spherically symmetric static body. The static limit of our result will... |
A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10$\%$ of the age of the universe today, is analyzed to put a constraint on a varying proton--electron mass ratio, $\mu$. A high resolution spectrum of the J1443$+$2724 quasar, which was observed with the Very Large Telescope, is ... |
Deep radio observations of galaxy clusters have revealed the existence of diffuse radio sources related to the presence of relativistic electrons and weak magnetic fields in the intracluster volume. The role played by this non-thermal intracluster component on the thermodynamical evolution of galaxy clusters is debate... |
Modern cosmology rests on the working assumption that the Universe is isotropic and homogeneous at large scales. Here, we document a number of anomalous observations pointing to an anisotropic Universe in a direction consistent with the CMB dipole. |
We report a measurement of the Type Ia supernova (SN Ia) rate in galaxy clusters at 0.9 < z < 1.45 from the Hubble Space Telescope (HST) Cluster Supernova Survey. This is the first cluster SN Ia rate measurement with detected z > 0.9 SNe. |
We study how Abelian-gauge-field production during inflation affects scalar perturbations in the case when the gauge field interacts with the inflaton directly (by means of generic kinetic and axial couplings) and via gravity. The homogeneous background solution is defined by self-consistently taking into account the ... |
We consider a general class of axion models, including the QCD and string axion, in which the PQ symmetry is broken before or during inflation. Assuming the axion is the dominant component of the dark matter, we discuss axion star formation in virialized dark minihalos around primordial black holes through gravitation... |
An accurate theoretical description of structure formation at least in the mildly non-linear regime is essential for comparison with data from next generation galaxy surveys. In a recent approach one follows the time evolution of correlators directly and finds a hierarchy of evolution equations with increasing order (... |
This paper describes the aims, objectives and first results of the observational program for the study of distant core-collapse supernovae (SNe) with redshifts z < 0.3. This work is done within the framework of an international cooperation program on the SNe monitoring at the 6-m BTA telescope of the Special Astrop... |
We investigate the observed galaxy power spectrum for the thawing class of scalar field models taking into account various general relativistic corrections that occur on very large scales. We consider the full general relativistic perturbation equations for the matter as well as the dark energy fluid. |
Determination of cosmological parameters is a major goal in cosmology at present. The availability of improved data sets necessitates the development of novel statistical tools to interpret the inference from a cosmological model. |
For future surveys of fast radio bursts (FRBs), we clarify information available from cosmic dispersion measures (DMs) through cross-correlation analyses of foreground dark matter haloes (hosting galaxies and galaxy clusters) with their known redshifts. With a halo-model approach, we predict that the cross-correlation... |
We identify a new class of time periodic attractor solutions in scalar field cosmology, which we term Cosmological Frequency Combs (CFC). These solutions arise in exponential quintessence models with a phantom matter background and exhibit coherent phase-locked oscillations in the scalar field's normalized variabl... |
We present a novel approach to the construction of mock galaxy catalogues for large-scale structure analysis based on the distribution of dark matter halos obtained with effective bias models at the field level. We aim to produce mock galaxy catalogues capable of generating accurate covariance matrices for a number of... |
The light travel time differences in strong gravitational lensing systems allows an independent determination of the Hubble constant. This method has been successfully applied to several lens systems. |
We consider the reasons why a cuspy NFW-like profile persistently occurs in N-body simulations, in contradiction to some astronomical observations. The routine method of testing the convergence of N-body simulations (in particular, the negligibility of two-body scattering effect) is to find the conditions under which ... |
We present a void clustering analysis in configuration-space using the completed Sloan Digital Sky Survey IV (SDSS-IV) extended Baryon Oscillation Spectroscopic Survey (eBOSS) DR16 samples. These samples consist of Luminous Red Galaxies (LRG) combined with the high redshift tail of the SDSS-III Baryon Oscillation Spec... |
In this paper we have performed a comparative study of different types of oscillating dark energy models using the Metropolis algorithm of MCMC. Eight different oscillating parameterization being examined herein which have demonstrated considerable ability to fit the overall cosmological observations including Pantheo... |
In accelerating dark energy models, the estimates of H0 from Sunyaev-Zel'dovich effect (SZE) and X-ray surface brightness of galaxy clusters may depend on the matter content (Omega_M), the curvature (Omega_K) and the equation of state parameter (w). In this article, by using a sample of 25 angular diameter distanc... |
We consider the three-dimensional rotating motions of neutron stars blown by the "axion wind". Neutron star precession and spin can change from the magnetic moment coupling to the oscillating axion background field, in analogy to the gyroscope motions with a driving force and the laboratory Nuclear Magnetic Re... |
The nature of galaxy structures on large scales is a key observational prediction for current models of galaxy formation. The SDSS and 2dF galaxy surveys have revealed a number of structures on 40-150 h^-1 Mpc scales at low redshifts, and some even larger ones. |
This is the second paper in a series whose aim is to predict the power spectrum of intensity and polarized intensity from cosmic reionization fronts. After building the analytic models for intensity and polarized intensity calculations in paper I, here we apply these models to simulations of reionization. |
By reaching through shrouding blastwaves, efficiently discovering off-axis events, and probing the central engine at work, gravitational wave (GW) observations will soon revolutionize the study of gamma-ray bursts. Already, analyses of GW data targeting gamma-ray bursts have helped constrain the central engines of sel... |
Recently, inhomogeneous generalisations of the Friedmann-Lemaitre-Robertson-Walker cosmological models have gained interest in the astrophysical community and are more often employed to study cosmological phenomena. However, in many papers the inhomogeneous cosmological models are treated as an alternative to the FLRW... |
This paper summarises the potential of the LISA mission to constrain the expansion history of the universe using massive black hole binary mergers as gravitational wave standard sirens. After briefly reviewing the concept of standard siren, the analysis and methodologies of Ref. |
We provide an analysis of a convolutional neural network's ability to identify the lensing signal of single dark matter subhalos in strong galaxy-galaxy lenses in the presence of increasingly complex source light morphology. We simulate a balanced dataset of 800,000 strong lens images both perturbed and unperturbe... |
Weak gravitational lensing of the cosmic microwave background (CMB) carries imprints of the physics operating at redshifts much lower than that of recombination and serves as an important probe of cosmological structure formation, dark matter physics, and the mass of neutrinos. Reconstruction of the CMB lensing deflec... |
A deep understanding of the Epoch of Reionization is still missing in our knowledge of the universe. While future probes will allow us to test the precise evolution of the free electron fraction from redshifts between $z\simeq 6$ and $z\simeq 20$, at present one could ask what kind of reionization processes are allowe... |
Primordial black holes (PBHs) are supposed to form through the gravitational collapse of regions with large density fluctuations. The formation of PBHs inevitably leads to the emission of scalar-induced gravitational wave (SIGW) signals, offering a unique opportunity to test the hypothesis of PBHs as a constituent of ... |
Galaxy clusters are the largest gravitationally-bound structures in the Universe. As such, during merger events with similar systems, they release an enormous amount of energy that is dissipated through the formation of shock waves and turbulence in the intracluster medium (ICM), the hot ionised plasma permeating the ... |
We train deep learning models on thousands of galaxy catalogues from the state-of-the-art hydrodynamic simulations of the CAMELS project to perform regression and inference. We employ Graph Neural Networks (GNNs), architectures designed to work with irregular and sparse data, like the distribution of galaxies in the U... |
Reasonable parametrizations of the current Hubble data set of the expansion rate of our homogeneous and isotropic universe, after suitable smoothing of these data, strongly suggests that the area of the apparent horizon increases irrespective of whether the spatial curvature of the metric is open, flat or closed. Put ... |
In this work, we study a direction dependent power spectrum in anisotropic Finsler space-time. We use this direction dependent power spectrum to address the low-l power observed in WMAP and PLANCK data. |
Observed high-redshift QSOs, at z~6, may reside in massive dark matter (DM) halos of more than 10^{12} Msun and are thus expected to be surrounded by overdense regions. In a series of 10 constrained simulations, we have tested the environment of such QSOs. |
Supernovae arise from progenitor stars occupying the upper end of the initial mass function. Their extreme brightness allows individual massive stars to be detected at cosmic distances, lending supernovae great potential as tracers of the upper end of the IMF and its evolution. |
The observed baryon asymmetry, as well as potentially an asymmetry in the dark matter sector, can be produced through dissipative particle production during inflation. A distinctive feature of this mechanism is the generation of matter isocurvature perturbations that are fully (anti-)correlated with the dominant adiab... |
Primordial gravitational waves propagate almost unimpeded from the moment they are generated to the present epoch. Nevertheless, they are subject to convolution with a non-trivial transfer function. |
We use the Separate Universe technique to calibrate the dependence of linear and quadratic halo bias $b_1$ and $b_2$ on the local cosmic web environment of dark matter haloes. We do this by measuring the response of halo abundances at fixed mass and cosmic web tidal anisotropy $\alpha$ to an infinite wavelength initia... |
We present a new method for estimating galaxy cluster masses using weak-lensing magnification. The effect of weak-lensing magnification introduces a correlation between the position of foreground galaxy clusters and the density of background sources. |
Primordial black hole (PBH) formation from first-order phase transitions (FOPTs) combines two prevalent elements of beyond the Standard Model physics with wide-ranging consequences. We elaborate on a recently proposed scenario in which inhomogeneities in vacuum energy decay seed the overdensities that collapse to PBHs... |
The survey description and the near-, mid-, and far-infrared flux properties are presented for the 258 galaxies in the Local Volume Legacy (LVL). LVL is a Spitzer Space Telescope legacy program that surveys the local universe out to 11 Mpc, built upon a foundation of ultraviolet, H-alpha, and HST imaging from 11HUGS (... |
Line-intensity mapping (LIM) is an emerging approach to survey the Universe, using relatively low-aperture instruments to scan large portions of the sky and collect the total spectral-line emission from galaxies and the intergalactic medium. Mapping the intensity fluctuations of an array of lines offers a unique oppor... |
The galaxy cluster system RXCJ0225.9-4154 with the two sub-clusters A3016 and A3017 is embedded in a large-scale structure filament with signatures of filamentary accretion. A Chandra observation of this system shows the two clusters as well as a filament of X-ray emission connecting them and a galaxy group therein. |
The Unruh's thermal state in the vicinity of the event horizon of the black hole provides conditions where impinging particles can radiate other particles. The subsequent decays may eventually lead to observable radiation of photons and neutrinos induced even by massive particles with gravitational interaction onl... |
We study strongly supercooled cosmological phase transitions. We perform numerical lattice simulations of two-bubble collisions and demonstrate that, depending on the scalar potential, in the collision the field can either bounce to a false vacuum or remain oscillating around the true vacuum. |
Following our previous work in [JCAP 1206, 041 (2012)], in this paper, we continue our study of reconstructing $f(R)$ modified gravity models that can be connected to a single scalar field in general relativity via conformal transformation, which lead to scale-invariant power spectrum in the early universe. With $f(R)... |
This paper explores the impact of primordial black holes (PBHs) on the abundance of low-mass haloes and subhaloes in the dark and low-stellar-mass regime, and examines how these effects can be measured through fluctuations in strong lensing and brightness fluctuations in clusters of galaxies, providing potential ways t... |
As a natural consequence of galaxy mergers, binary active galactic nuclei (AGNs) should be commonplace. Nevertheless, observational confirmations are rare, especially for binaries with separations less than ten kpc. |
Following our previous work, which related generic features in the sky-averaged (global) 21-cm signal to properties of the intergalactic medium, we now investigate the prospects for constraining a simple galaxy formation model with current and near-future experiments. Markov-Chain Monte Carlo fits to our synthetic dat... |
The DESI collaboration just obtained a set of precise BAO measurements, that combined with CMB and SNIa datasets show that the $\omega_0 \omega_a$CDM model is preferred over $\Lambda$CDM, at more than $4\,\sigma$, to describe the dynamics of the expanding Universe. This raises the question whether this model also suit... |
Since WMAP and Planck some anomalous features appeared in the Cosmic Microwave Background (CMB) large-angle anisotropy, the so-called anomalies. One of these is the hemispherical power asymmetry, i.e. a difference in the average power on the two hemispheres centered around (l, b) = (221, -20), which shows a relatively... |
Dark energy might directly interact with cold dark matter. However, in such a scenario, an early-time large-scale instability occurs occasionally, which may be due to the incorrect treatment for the pressure perturbation of dark energy as a nonadiabatic fluid. |
In the standard inflationary scenario based on a minimally coupled scalar field, canonical or non-canonical, the subluminal propagation of speed of scalar perturbations ensures the following consistency relation: $r \leq - 8n_{_T}$, where $r$ is the tensor-to-scalar-ratio and $n_{_T}$ is the spectral index for tensor p... |
Gravitational lensing can provide pure geometric tests of the structure of space-time, for instance by determining empirically the angular diameter distance-redshift relation. This geometric test has been demonstrated several times using massive clusters which produce a large lensing signal. |
A new and powerful probe of the origin and evolution of structures in the Universe has emerged and been actively developed over the last decade. In the coming decade, non-Gaussianity, i.e., the study of non-Gaussian contributions to the correlations of cosmological fluctuations, will become an important probe of both ... |
One of the stumbling blocks for studying the evolution of interstellar molecules is the lack of adequate knowledge of the rate co-efficients of various reactions which take place in the Interstellar medium and molecular clouds. Some of the theoretical models of rate coefficients do exist in the literature for computin... |
We make use of snapshots taken from the Quijote suite of simulations, consisting of 2000 simulations where five cosmological parameters have been varied ($\Omega_m$, $\Omega_b$, $h$, $n_s$ and $\sigma_8$) in order to investigate the possibility of determining them using machine learning techniques. In particular, we s... |
Visual inspections of the first optical rest-frame images from JWST have indicated a surprisingly high fraction of disk galaxies at high redshifts. Here, we alternatively apply self-supervised machine learning to explore the morphological diversity at $z \geq 3$. |
Recently, observations by PAMELA, the Fermi Gamma Ray Space Telescope, and other cosmic ray experiments have generated a great deal of interest in dark matter (DM) particles which annihilate at a high rate to leptons. In this letter, we explore the possibility of using large volume neutrino telescopes, such as IceCube... |
With a statistical detection of the 21 cm signal fluctuations from the Epoch of Reionization (EoR) expected in the next few years, there is an interest in developing robust and precise techniques to constrain the underlying astrophysical parameters. Bayesian inference with Markov Chain Monte Carlo, or different types ... |
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