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Propagating Speed of Primordial Gravitational Waves: Primordial Gravitational Waves, i.e. a background of metric perturbations sourced by the quantum inflationary fluctuations, if measured, could both provide a substantial evidence for primordial inflation and shed light on physics at extremely high energy scales. In t...
astro-ph_CO
Cosmological constraints on the velocity-dependent baryon-dark matter coupling: We present the cosmological constraints on the cross section of baryon-dark matter interactions for the dark matter mass below the MeV scale from the Planck CMB (cosmic microwave background) and SDSS (Sloan Digital Sky Survey) Lyman-$\alp...
astro-ph_CO
On the apparent absence of broad iron lines in Seyfert galaxies: We present an analysis of XMM-Newton observations of eleven Seyfert galaxies that appear to be missing a broad iron K alpha line. These objects represent a challenge to the established paradigm for active galactic nuclei, where a relatively cold accretion...
astro-ph_CO
Gravitational lensing effects on sub-millimetre galaxy counts: We study the effects on the number counts of sub-millimetre galaxies due to gravitational lensing. We explore the effects on the magnification cross section due to halo density profiles, ellipticity and cosmological parameter (the power-spectrum normalisati...
astro-ph_CO
A fast and accurate method to compute the mass return from multiple stellar populations: The mass returned to the ambient medium by aging stellar populations over cosmological times sums up to a significant fraction (20% - 30% or more) of their initial mass. This continuous mass injection plays a fundamental role in ...
astro-ph_CO
The origin of dispersion in DLA metallicities: Recent chemical abundance measurements of damped Ly-alpha absorbers (DLAs) revealed an intrinsic scatter in their metallicity of ~0.5 dex out to z~5. In order to explore the origin of this scatter, we build a semi-analytic model which traces the chemical evolution of the i...
astro-ph_CO
Isotropy of low redshift type Ia Supernovae: A Bayesian analysis: The standard cosmology strongly relies upon the Cosmological Principle, which consists on the hypotheses of large scale isotropy and homogeneity of the Universe. Testing these assumptions is, therefore, crucial to determining if there are deviations from...
astro-ph_CO
Optimal filtering of optical and weak lensing data to search for galaxy clusters: application to the COSMOS field: Galaxy clusters are usually detected in blind optical surveys via suitable filtering methods. We present an optimal matched filter which maximizes their signal-to-noise ratio by taking advantage of the k...
astro-ph_CO
Clusters in the Disperse cosmic web: Galaxy cluster mass halos ("clusters") in a dark matter simulation are matched to nodes in several different cosmic webs found using the Disperse cosmic web finder. The webs have different simulation smoothings and Disperse parameter choices; for each, 4 methods are considered for m...
astro-ph_CO
Extraterrestrial Axion Search with the Breakthrough Listen Galactic Center Survey: Axion dark matter (DM) may efficiently convert to photons in the magnetospheres of neutron stars (NSs), producing nearly monochromatic radio emission. This process is resonantly triggered when the plasma frequency induced by the underl...
astro-ph_CO
Is $w \neq -1$ evidence for a dynamical dark energy equation of state ?: Current constraints on the dark energy equation of state parameter, $w$, are expected to be improved by more than one order of magnitude in the next decade. If $|w-1| \gsim 0.01$ around the present time, but the dark energy dynamics is sufficientl...
astro-ph_CO
Does a 'stochastic' background of gravitational waves exist in the pulsar timing band?: We investigate the effects of gravitational waves (GWs) from a simulated population of binary super-massive black holes (SMBHs) on pulsar timing array datasets. We construct a distribution describing the binary SMBH population fro...
astro-ph_CO
Scale-invariant enhancement of gravitational waves during inflation: The inflationary 1-loop tensor power spectrum from an excited spectator scalar field is calculated. Recent studies on primordial black holes suggest that the inflationary curvature perturbation may be huge on small scales. An enhanced curvature pertur...
astro-ph_CO
Witnessing the Formation of a Brightest Cluster Galaxy in a Nearby X-ray Cluster: The central dominant galaxies in galaxy clusters constitute the most massive and luminous galaxies in the Universe. Despite this, the formation of these brightest cluster galaxies (BCGs) and the impact of this on the surrounding cluster...
astro-ph_CO
The Cosmic Web of Baryons: Only about 10% of the baryons in the universe lie in galaxies as stars or cold gas, with the remainder predicted to exist as a dilute gaseous filamentary network known as the Cosmic Web. Some of this gas is detected through UV absorption line studies, but half of the gas remains undetected. G...
astro-ph_CO
Mass-radius relation of Newtonian self-gravitating Bose-Einstein condensates with short-range interactions: II. Numerical results: We develop the suggestion that dark matter could be a Bose-Einstein condensate. We determine the mass-radius relation of a Newtonian self-gravitating Bose-Einstein condensate with short-r...
astro-ph_CO
Primordial non-gaussianity from the bispectrum of 21-cm fluctuations in the dark ages: A measurement of primordial non-gaussianity will be of paramount importance to distinguish between different models of inflation. Cosmic microwave background (CMB) anisotropy observations have set unprecedented bounds on the non-ga...
astro-ph_CO
Is the expansion of the universe accelerating? All signs still point to yes a local dipole anisotropy cannot explain dark energy: Type Ia supernovae (SNe Ia) provided the first strong evidence that the expansion of the universe is accelerating. With SN samples now more than ten times larger than those used for the or...
astro-ph_CO
Bayesian evidence of the post-Planck curvaton: We perform a Bayesian model comparison for scenarios within the quadratic curvaton model, determining the degree to which both are disfavoured with respect to the $\Lambda$CDM concordance model and single-field quadratic inflation, using the recent \emph{Planck} data relea...
astro-ph_CO
Introduction to Early Universe Cosmology: Observational cosmology is in its "golden age" with a vast amount of recent data on the distribution of matter and light in the universe. This data can be used to probe theories of the very early universe. It is small amplitude cosmological fluctuations which encode the informa...
astro-ph_CO
A New Constraint on the Simulation of the Intergalactic Medium through the Evolution of the Neutral Hydrogen Fraction in the Epoch of Reionization: The thermal history of the intergalactic medium is full of extremely useful data in the field of astrophysics and cosmology. In other words, by examining this environment...
astro-ph_CO
Measuring Microlensing using Spectra of Multiply Lensed Quasars: We report on a program of spectroscopic observations of gravitationally-lensed QSOs with multiple images. We seek to establish whether microlensing is occurring in each QSO image using only single-epoch observations. We calculate flux ratios for the cores...
astro-ph_CO
Vector field instability and the primordial tensor spectrum: It has recently been shown that the presence of a spectator pseudoscalar field, coupled to photons through a Chern-Simons term, can amplify the primordial tensor spectrum without observationally disrupting the primordial scalar spectrum. The amplification occ...
astro-ph_CO
The Epoch of Reionization in the R_h=ct Universe: The measured properties of the epoch of reionization (EoR) show that reionization probably began around z ~ 12-15 and ended by z=6. In addition, a careful analysis of the fluctuations in the cosmic microwave background indicate a scattering optical depth tau ~ 0.066+/-0...
astro-ph_CO
The Spitzer Extragalactic Representative Volume Survey (SERVS): The Environments of High-z SDSS Quasi-Stellar-Objects: This paper presents a study of the environments of SDSS Quasi-Stellar-Objects (QSOs) in the Spitzer Extragalactic Representative Volume Survey (SERVS). We concentrate on the high-redshift QSOs as the...
astro-ph_CO
(Mis-)Interpreting supernovae observations in a lumpy universe: Light from `point sources' such as supernovae is observed with a beam width of order of the sources' size - typically less than 1 AU. Such a beam probes matter and curvature distributions that are very different from coarse-grained representations in N-bod...
astro-ph_CO
The Abundance Scatter in M33 from HII Regions: Is There Any Evidence for Azimuthal Metallicity Variations?: Optical spectra of 25 H II regions in the inner two kpc of the M33 disk have been obtained with the GMOS spectrograph at the Gemini North telescope. The oxygen abundance gradient measured from the detection of ...
astro-ph_CO
Reconstruction of Power Spectrum of Primordial Curvature Perturbations on small scales from Primordial Black Hole Binaries scenario of LIGO/VIRGO detection: As a candidate bound for the Binary Black Hole (BBH) merger events detected by LIGO/Virgo, Primordial Black Holes (PBHs) provide a useful tool to investigate t...
astro-ph_CO
Blue Fermi Flat Spectrum Radio Quasars: Many blazars detected by the Fermi satellite, observed spectroscopically in the optical, are line-less, and have been classified as BL Lac objects. Optical-UV photometry of nearly one hundred of them allowed to determine the redshift for a handful of objects and redshift upper li...
astro-ph_CO
Internal dynamics of Abell 1240: a galaxy cluster with symmetric double radio relics: We aim to obtain new insights into the internal dynamics of the cluster Abell 1240, showing the presence of two roughly symmetric radio relics, separated by ~2 h_70^-1 Mpc. Our analysis is mainly based on redshift data for 145 galax...
astro-ph_CO
Broadband Imaging Segregation of z ~ 3 Ly-alpha Emitting and Ly-alpha Absorbing Galaxies: The spectral properties of Lyman break galaxies (LBGs) offer a means to isolate pure samples displaying either dominant Ly-alpha in absorption or Ly-alpha in emission using broadband information alone. We present criteria develo...
astro-ph_CO
All-Sky Analysis of the General Relativistic Galaxy Power Spectrum: We perform an all-sky analysis of the general relativistic galaxy power spectrum using the well-developed spherical Fourier decomposition. Spherical Fourier analysis expresses the observed galaxy fluctuation in terms of the spherical harmonics and sphe...
astro-ph_CO
PNe as observational constraints in chemical evolution models for NGC 6822: Chemical evolution models are useful for understanding the formation and evolution of stars and galaxies. Model predictions will be more robust as more observational constraints are used. We present chemical evolution models for the dwarf irr...
astro-ph_CO
Non-Gaussianity from false vacuum inflation: Old curvaton scenario: We calculate the three-point correlation function of the comoving curvature perturbation generated during an inflationary epoch driven by false vacuum energy. We get a novel false vacuum shape bispectrum, which peaks in the equilateral limit. Using thi...
astro-ph_CO
Utilizing Astroinformatics to Maximize the Science Return of the Next Generation Virgo Cluster Survey: The Next Generation Virgo Cluster Survey is a 104 square degree survey of the Virgo Cluster, carried out using the MegaPrime camera of the Canada-France-Hawaii telescope, from semesters 2009A-2012A. The survey will ...
astro-ph_CO
Steve: A hierarchical Bayesian model for Supernova Cosmology: We present a new Bayesian hierarchical model (BHM) named Steve for performing type Ia supernova (SNIa) cosmology fits. This advances previous works by including an improved treatment of Malmquist bias, accounting for additional sources of systematic uncertai...
astro-ph_CO
A fast empirical method for galaxy shape measurements in weak lensing surveys: We describe a simple and fast method to correct ellipticity measurements of galaxies from the distortion by the instrumental and atmospheric point spread function (PSF), in view of weak lensing shear measurements. The method performs a cla...
astro-ph_CO
The Link Between the Hidden Broad Line Region and the Accretion Rate in Seyfert 2 Galaxies: In the past few years more and more pieces of evidence have been presented for a revision of the widely accepted Unified Model of Active Galactic Nuclei. A model based solely on orientation cannot explain all the observed phen...
astro-ph_CO
IC10: the history of the nearest starburst galaxy through its Planetary Nebula and HII region populations: We report the results of spectroscopic observations, obtained with the Gemini North Multi-Object Spectrograph, of 9 planetary nebulae (PNe) and 15 \hii\ regions located in the 5.5\arcmin $\times$5.5\arcmin inner...
astro-ph_CO
The role of Dark Matter sub-halos in the non-thermal emission of galaxy clusters: Annihilation of Dark Matter (DM) particles has been recognized as one of the possible mechanisms for the production of non-thermal particles and radiation in galaxy clusters. Previous studies have shown that, while DM models can reprodu...
astro-ph_CO
Improved Cosmological Constraints from SDSS redMaPPer Clusters via X-ray Follow-up of a Complete Subsample of Systems: We improve upon the cosmological constraints derived from the abundance and weak-lensing data of redMaPPer clusters detected in the Sloan Digital Sky Survey (SDSS). Specifically, we derive gas mass d...
astro-ph_CO
The zCOSMOS 20k Group Catalog: We present an optical group catalog between 0.1 < z < 1 based on 16,500 high-quality spectroscopic redshifts in the completed zCOSMOS-bright survey. The catalog published herein contains 1498 groups in total and 192 groups with more than five observed members. The catalog includes both gr...
astro-ph_CO
An exploration of an early gravity transition in light of cosmological tensions: We study a step-like transition in the value of the effective Planck mass (or effective gravitational constant) on cosmological scales prior to recombination. We employ CMB, BAO, and SNIa data and find they are sufficient to strongly con...
astro-ph_CO
Is the misalignment of the Local Group velocity and the 2MASS Redshift Survey dipole typical in a LambdaCDM model?: We predict the acceleration of the Local Group generated by the 2MASS Redshift Survey within the framework of LambdaCDM and the halo model of galaxies. We show that as the galaxy fluctuations derived fr...
astro-ph_CO
Instability in axion inflation with strong backreaction from gauge modes: We perform an analytical study of the stability of the background solution of the model in which an inflaton, through an axionic coupling to a $U(1)$ gauge field, causes an amplification of the gauge field modes that strongly backreact on its dyn...
astro-ph_CO
Testable dark energy predictions from current data: Given a class of dark energy models, constraints from one set of cosmic acceleration observables make predictions for other observables. Here we present the allowed ranges for the expansion rate H(z), distances D(z), and the linear growth function G(z) (as well as oth...
astro-ph_CO
Probing Parity Violation in the Stochastic Gravitational Wave Background with Astrometry: Astrometry holds the potential for testing fundamental physics through the effects of the Stochastic Gravitational Wave Background (SGWB) in the $\sim 1-100$ nHz frequency band on precision measurements of stellar positions. Suc...
astro-ph_CO
Probing the anisotropic expansion history of the universe with cosmic microwave background: We propose a simple technique to detect any anisotropic expansion stage in the history of the universe starting from the inflationary stage to the surface of last scattering from the CMBR data. We use the property that any ani...
astro-ph_CO
Absence of concordance in a simple self-interacting neutrino cosmology: Some cosmic microwave background (CMB) data allow a cosmological scenario in which the free streaming of neutrinos is delayed until close to matter-radiation equality. Interestingly, recent analyses have revealed that large-scale structure (LSS) da...
astro-ph_CO
The role of Dark Matter sub-halos in the non-thermal emission of galaxy clusters: Annihilation of Dark Matter (DM) particles has been recognized as one of the possible mechanisms for the production of non-thermal particles and radiation in galaxy clusters. Previous studies have shown that, while DM models can reprodu...
astro-ph_CO
All sky angular power spectrum: I. Estimating brightness temperature fluctuations using TGSS 150 MHz survey: Measurements of the Galactic synchrotron emission is relevant for the 21-cm studies from the Epoch of Reionization. The study of the synchrotron emission is also useful to quantify the fluctuations in the magn...
astro-ph_CO
Gödel-type universes and chronology protection in Horava-Lifshitz gravity: In the attempts toward a quantum gravity theory, general relativity faces a serious difficulty since it is non-renormalizable theory. Ho\v{r}ava-Lifshitz gravity offers a framework to circumvent this difficulty, by sacrificing the local Lorent...
astro-ph_CO
A Bayesian analysis of redshifted 21-cm HI signal and foregrounds: Simulations for LOFAR: Observations of the EoR with the 21-cm hyperfine emission of neutral hydrogen (HI) promise to open an entirely new window onto the formation of the first stars, galaxies and accreting black holes. In order to characterize the we...
astro-ph_CO
Structure in Galaxy Distribution. III. Fourier Transforming the Universe: We demonstrate the effectiveness of a relatively straightforward analysis of the complex 3D Fourier transform of galaxy coordinates derived from redshift surveys. Numerical demonstrations of this approach are carried out on a volume-limited sampl...
astro-ph_CO
Simulations of helical inflationary magnetogenesis and gravitational waves: Using numerical simulations of helical inflationary magnetogenesis in a low reheating temperature scenario, we show that the magnetic energy spectrum is strongly peaked at a particular wavenumber that depends on the reheating temperature. Gra...
astro-ph_CO
Inflation, Quantum Field Renormalization, and CMB Anisotropies: We point out that if quantum field renormalization is taken into account the predictions of slow-roll inflation for both the scalar and tensorial power spectra change significantly for wavelengths that today are at observable scales
astro-ph_CO
First measurement of the bulk flow of nearby galaxies using the cosmic microwave background: Peculiar velocities in the nearby Universe can be measured via the kinetic Sunyaev-Zel'dovich (kSZ) effect. Using a statistical method based on an optimised cross-correlation with nearby galaxies, we extract the kSZ signal ge...
astro-ph_CO
All about baryons: revisiting SIDM predictions at small halo masses: We use cosmological hydrodynamic simulations to consistently compare the assembly of dwarf galaxies in both $\Lambda$ dominated, Cold (CDM) and Self--Interacting (SIDM) dark matter models. The SIDM model adopts a constant cross section of 2 $cm^{2}/g$...
astro-ph_CO
Calculation of the critical overdensity in the spherical-collapse approximation: Critical overdensity $\delta_c$ is a key concept in estimating the number count of halos for different redshift and halo-mass bins, and therefore, it is a powerful tool to compare cosmological models to observations. There are currently ...
astro-ph_CO
The Atacama Cosmology Telescope (ACT): Beam Profiles and First SZ Cluster Maps: The Atacama Cosmology Telescope (ACT) is currently observing the cosmic microwave background with arcminute resolution at 148 GHz, 218 GHz, and 277 GHz. In this paper, we present ACT's first results. Data have been analyzed using a maximu...
astro-ph_CO
Hot Gas, Cold Gas and Sub-Halos in a Lyman-alpha Blob at Redshift 2.38: We present integral field spectroscopy of a Lyman-alpha blob at redshift 2.38, with a spectral resolution three times better than previous published work. As with previous observations, the blob has a chaotic velocity structure, much of which break...
astro-ph_CO
Arbitrating the $S_8$ discrepancy with growth rate measurements from Redshift-Space Distortions: Within the $\Lambda$CDM model, measurements from recent Cosmic Microwave Background (CMB) and weak lensing (WL) surveys have uncovered a $\sim 3\sigma$ disagreement in the inferred value of the parameter $S_8 \equiv \sigm...
astro-ph_CO
Extragalactic dark matter and direct detection experiments: Recent astronomical data strongly suggest that a significant part of the dark matter, composing the Local Group and Virgo Supercluster, is not incorporated into the galaxy haloes and forms diffuse components of these galaxy clusters. Apparently, a portion of t...
astro-ph_CO
A general framework to test gravity using galaxy clusters III: Observable-mass scaling relations in $f(R)$ gravity: We test two methods, including one that is newly proposed in this work, for correcting for the effects of chameleon $f(R)$ gravity on the scaling relations between the galaxy cluster mass and four obser...
astro-ph_CO
Testing theories in barred spiral galaxies: According to one version of the recently proposed "manifold" theory that explains the origin of spirals and rings in relation to chaotic orbits, galaxies with stronger bars should have a higher spiral arms pitch angle when compared to galaxies with weaker bars. A sub-sample o...
astro-ph_CO
Probing below the neutrino floor with the first generation of stars: We show that the mere observation of the first stars (Pop III stars) in the universe can be used to place tight constraints on the strength of the interaction between dark matter and regular, baryonic matter. We apply this technique to a candidate Pop...
astro-ph_CO
Absence of a Periodic Component in Quasar z-Distribution: Since the discovery of quasars in papers often appeared and appear the assertions that the redshift quasar distribution includes a periodic component with the period $\Delta z = 0.063$ or 0.11. A statement of such kind, if it is correct, may manifest the existen...
astro-ph_CO
An Improved Calculation of the Non-Gaussian Halo Mass Function: The abundance of collapsed objects in the universe, or halo mass function, is an important theoretical tool in studying the effects of primordially generated non-Gaussianities on the large scale structure. The non-Gaussian mass function has been calculated...
astro-ph_CO
A new analysis of fine-structure constant measurements and modelling errors from quasar absorption lines: We present an analysis of 23 absorption systems along the lines of sight towards 18 quasars in the redshift range of $0.4 \leq z_{abs} \leq 2.3$ observed on the Very Large Telescope (VLT) using the Ultraviolet an...
astro-ph_CO
Photodissociation chemistry footprints in the Starburst galaxy NGC 253: We report the first detection of PDR molecular tracers, namely HOC+, and CO+, and confirm the detection of the also PDR tracer HCO towards the starburst galaxy NGC 253, claimed to be mainly dominated by shock heating and in an earlier stage of evol...
astro-ph_CO
$H_0$ Tension, Phantom Dark Energy and Cosmological Parameter Degeneracies: Phantom dark energy can produce amplified cosmic acceleration at late times, thus increasing the value of $H_0$ favored by CMB data and releasing the tension with local measurements of $H_0$. We show that the best fit value of $H_0$ in the co...
astro-ph_CO
Velocity waves in the Hubble diagram: signature of local galaxy clusters: The Universe expansion rate is modulated around local inhomogeneities due to their gravitational potential. Velocity waves are then observed around galaxy clusters in the Hubble diagram. This paper studies them in a ~738 Mpc wide, with 2048^3 par...
astro-ph_CO
How clustering dark energy affects matter perturbations: The rate of structure formation in the Universe is different in homogeneous and clustered dark energy models. The degree of dark energy clustering depends on the magnitude of its effective sound speed $c^{2}_{\rm eff}$ and for $c_{\rm eff}=0$ dark energy clusters...
astro-ph_CO
Newtonian acceleration scales in spiral galaxies: We revisit the issue of the constancy of the dark matter (DM) and baryonic Newtonian acceleration scales within the DM scale radius by considering a large sample of late - type galaxies. We rely on a Markov Chain Monte Carlo (MCMC) method to estimate the parameters of t...
astro-ph_CO
New Strong Line Abundance Diagnostics for \HII Regions: Effects of $κ$-Distributed Electron Energies and New Atomic Data: Recently, \citet{Nicholls12}, inspired by \emph{in situ} observations of solar system astrophysical plasmas, suggested that the electrons in \HII regions are characterised by a $\kappa$-distributi...
astro-ph_CO
Cosmology-marginalized approaches in Bayesian model comparison: the neutrino mass as a case study: We propose here a \emph{novel} method which singles out the \emph{a priori} unavoidable dependence on the underlying cosmological model when extracting parameter constraints, providing robust limits which only depend on...
astro-ph_CO
Measuring the global 21-cm signal with the MWA-I: improved measurements of the Galactic synchrotron background using lunar occultation: We present early results from a project to measure the sky-averaged (global), redshifted $21\,$cm signal from the Epoch of Reionisation (EoR), using the Murchison Widefield Array (MW...
astro-ph_CO
Constraints on the abundance of primordial black holes with different mass distributions from lensing of fast radio bursts: Primordial black holes (PBHs) has been considered to form a part of dark matter for a long time but the possibility has been poorly constrained over a wide mass range, including the stellar mass...
astro-ph_CO
Evolution of X-ray Cavities in Galaxy Clusters: The physics of X-ray cavities in galaxy clusters is constrained by their observed morphological evolution, which depends on such poorly-understood properties as the turbulent density field and magnetic fields. Here we combine numerical simulations that include subgrid tur...
astro-ph_CO
A Redshift Survey of Herschel Far-Infrared Selected Starbursts and Implications for Obscured Star Formation: We present Keck spectroscopic observations and redshifts for a sample of 767 Herschel-SPIRE selected galaxies (HSGs) at 250, 350, and 500um, taken with the Keck I Low Resolution Imaging Spectrometer (LRIS) and...
astro-ph_CO
A new gravitational N-body simulation algorithm for investigation of cosmological chaotic advection: Recently alternative approaches in cosmology seeks to explain the nature of dark matter as a direct result of the non-linear spacetime curvature due to different types of deformation potentials. In this context, a key...
astro-ph_CO
The evolution of galaxy intrinsic alignments in the MassiveBlack II universe: We investigate the redshift evolution of the intrinsic alignments (IA) of galaxies in the \texttt{MassiveBlackII} (MBII) simulation. We select galaxy samples above fixed subhalo mass cuts ($M_h>10^{11,12,13}~M_{\odot}/h$) at $z=0.6$ and tra...
astro-ph_CO
The (black hole mass)-(host spheroid luminosity) relation at high and low masses, the quadratic growth of black holes, and intermediate-mass black hole candidates: From a sample of 72 galaxies with reliable supermassive black hole masses M_(bh), we derive the M_(bh)-(host spheroid luminosity, L) relation for (i) th...
astro-ph_CO
The eROSITA Final Equatorial-Depth Survey (eFEDS): Characterization of Morphological Properties of Galaxy Groups and Clusters: Understanding the cluster population of clusters of galaxies is of the utmost importance for using cluster samples in both astrophysical and cosmological studies. We present an in-depth analy...
astro-ph_CO
Relativistic and non-Gaussianity contributions to the one-loop power spectrum: We compute the one-loop density power spectrum including Newtonian and relativistic contributions, as well as the primordial non-Gaussianity contributions from $f_{\rm NL}$ and $g_{\rm NL}$ in the local configuration. To this end we take s...
astro-ph_CO
Hunting WIMPs with LISA: Correlating dark matter and gravitational wave signals: The thermal freeze-out mechanism in its classical form is tightly connected to physics beyond the Standard Model around the electroweak scale, which has been the target of enormous experimental efforts. In this work we study a dark matte...
astro-ph_CO
Intrinsic Shapes of Very Flat Elliptical Galaxies: Photometric data from the literature is combined with triaxial mass models to derive variation in the intrinsic shapes of the light distribution of elliptical galaxies NGC 720, 2768 and 3605. The inferred shape variation in given by a Bayesian probability distribution,...
astro-ph_CO
Inflationary tensor fossils in large-scale structure: Inflation models make specific predictions for a tensor-scalar-scalar three-point correlation, or bispectrum, between one gravitational-wave (tensor) mode and two density-perturbation (scalar) modes. This tensor-scalar-scalar correlation leads to a local power quadr...
astro-ph_CO
The 6x2pt method: supernova velocities meet multiple tracers: We present a new methodology to analyse in a comprehensive way large-scale and supernovae (or any other distance indicator) surveys. Our approach combines galaxy and supernova position and redshift data with supernova peculiar velocities, obtained through th...
astro-ph_CO
Evidence for Three Accreting Black Holes in a Galaxy at z~1.35: A Snapshot of Recently Formed Black Hole Seeds?: One of the key open questions in cosmology today pertains to understanding when, where and how super massive black holes form, while it is clear that mergers likely play a significant role in the growth cy...
astro-ph_CO
Contamination of the Epoch of Reionization power spectrum in the presence of foregrounds: We construct foreground simulations comprising spatially correlated extragalactic and diffuse Galactic emission components and calculate the `intrinsic' (instrument-free) two-dimensional spatial power spectrum and the cylindrica...
astro-ph_CO
Induced Gravity and the Attractor Dynamics of Dark Energy/Dark Matter: Attractor solutions that give dynamical reasons for dark energy to act like the cosmological constant, or behavior close to it, are interesting possibilities to explain cosmic acceleration. Coupling the scalar field to matter or to gravity enlarges ...
astro-ph_CO
A Survey of z~6 Quasars in the SDSS Deep Stripe. II. Discovery of Six Quasars at z_{AB}>21: We present the discovery of six new quasars at z~6 selected from the Sloan Digital Sky Survey (SDSS) southern survey, a deep imaging survey obtained by repeatedly scanning a stripe along the celestial equator. The six quasars ...
astro-ph_CO
Accurate photometric redshift probability density estimation - method comparison and application: We introduce an ordinal classification algorithm for photometric redshift estimation, which significantly improves the reconstruction of photometric redshift probability density functions (PDFs) for individual galaxies a...
astro-ph_CO
Testing physical models for dipolar asymmetry with CMB polarization: The cosmic microwave background (CMB) temperature anisotropies exhibit a large-scale dipolar power asymmetry. To determine whether this is due to a real, physical modulation or is simply a large statistical fluctuation requires the measurement of new ...
astro-ph_CO
Curvature Perturbations and non-Gaussianities from Waterfall Phase Transition during Inflation: We consider a variant of hybrid inflation where the waterfall phase transition happens during inflation. By adjusting the parameters associated with the mass of the waterfall field we arrange that the phase transition is n...
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Observational constraints on the metagalactic Ly$α$ photon scattering rate at high redshift: The scattering of Ly$\alpha$ photons from the first radiating sources in the Universe plays a pivotal role in 21-cm radio detections of Cosmic Dawn and the Epoch of Reionization through the Wouthuysen-Field effect. New data f...
astro-ph_CO
Discovery of a diffuse optical line emitting halo in the core of the Centaurus cluster of galaxies: Line emission outside the protection of the filaments: We present the discovery of diffuse optical line emission in the Centaurus cluster seen with the MUSE IFU. The unparalleled sensitivity of MUSE allows us to dete...
astro-ph_CO
Multiwavelength study of nearly face-on low surface brightness disk galaxies: We study the ages of a large sample (1,802) of nearly face-on disk low surface brightness galaxies (LSBGs) by using the evolutionary population synthesis (EPS) model PEGASE with exponential decreasing star formation rate to fit their multiw...
astro-ph_CO
Large-Scale Clustering of Cosmic Voids: We study the clustering of voids using $N$-body simulations and simple theoretical models. The excursion-set formalism describes fairly well the abundance of voids identified with the watershed algorithm, although the void formation threshold required is quite different from the ...
astro-ph_CO