Arxiv Papers

Last entries in the CiteULike library

For the full list: http://www.citeulike.org/group/13962/

Earlier
(15 Jan 2018)Cosmological models that invoke a multiverse - a collection of unobservable regions of space where conditions are very different from the region around us - are controversial, on the grounds that unobservable phenomena shouldn't play a crucial role in legitimate scientific theories. I argue that the way we [...]
Wed, Jan 17, 2018
Source: CiteULike Group Cosmo LUTH
(15 Jan 2018)Recent observations suggest that hydrogen reionization ends late ($z ∼eq 6$) and proceeds quickly. We present here a new model of the meta-galactic UV/X-ray background (UVB) that is consistent with this. It adopts the most recent determinations of the ionizing emissivity due to stars and AGN, as well [...]
Wed, Jan 17, 2018
Source: CiteULike Group Cosmo LUTH
(16 Jan 2018)In this paper we examine to what extent the radio continuum can be used as an extinction free probe of star formation in dwarf galaxies. To that aim we observe $40$ nearby dwarf galaxies with the Very Large Array at 6 cm ($4$-$8$ GHz) in C-configuration. We obtained [...]
Wed, Jan 17, 2018
Source: CiteULike Group Cosmo LUTH
(15 Jan 2018)Understanding the origin of strong galactic outflows and the suppression of star formation in dwarf galaxies is a key problem in galaxy formation. Using a set of radiation-hydrodynamic simulations of an isolated dwarf galaxy embedded in a $10^10\,M_odot$ halo, we show that the momentum transferred from resonantly scattered [...]
Wed, Jan 17, 2018
Source: CiteULike Group Cosmo LUTH
(15 Jan 2018)The scaling relations between the mass of supermassive black holes ($M_•$) and host galaxy properties (stellar mass, $M_∗$, and velocity dispersion, $σ$), provide a link between the growth of black holes (BHs) and that of their hosts. Here we investigate if and how the BH-galaxy relations are established [...]
Wed, Jan 17, 2018
Source: CiteULike Group Cosmo LUTH
(12 Jan 2018)Recent analysis shows that it is important to explicitly include the gravitational potential of the central brightest central galaxy (BCG) to infer the acceleration due to gravity ($g$) and the free-fall time ($t_ ff ≡ [2r/g]^1/2$) in cool cluster cores. Accurately measuring $t_ ff$ is crucial because according [...]
Tue, Jan 16, 2018
Source: CiteULike Group Cosmo LUTH
(13 Jan 2018)The Kennicutt-Schmidt (KS) relationship between the surface density of the star formation rate (SFR) and the gas surface density has three distinct power laws that may result from one model in which gas collapses at a fixed fraction of the dynamical rate. The power law slope is 1 [...]
Tue, Jan 16, 2018
Source: CiteULike Group Cosmo LUTH
(11 Jan 2018)We present results from the semi-analytic model of galaxy formation SAG applied on the MultiDark simulation MDPL2. SAG features an updated supernova (SN) feedback scheme and a robust modelling of the environmental effects on satellite galaxies. This incorporates a gradual starvation of the hot gas halo driven by [...]
Fri, Jan 12, 2018
Source: CiteULike Group Cosmo LUTH
(11 Jan 2018)We investigate galaxy formation in models with dark matter (DM) constituted by sterile neutrinos. Given their large parameter space, defined by the combinations of sterile neutrino mass $m_ν$ and mixing parameter $\sin^2(2θ)$ with active neutrinos, we focus on models with $m_ν=7$ keV, consistent with the tentative 3.5 keV [...]
Fri, Jan 12, 2018
Source: CiteULike Group Cosmo LUTH
(10 Jan 2018)The Schrodinger-Poisson equations describe the behavior of a superfluid condensate under self-gravity with a 3D wave function. As $\hbar/m\to 0$, with $m$ being the boson mass, the equations have been hypothesized to approximate the collisionless Vlasov-Poisson equations also known as the collisionless Boltzmann equations. The latter describe collisionless [...]
Fri, Jan 12, 2018
Source: CiteULike Group Cosmo LUTH
(9 Jan 2018)An optimally efficient explicit numerical scheme for solving fluid dynamics equations, or any other parabolic or hyperbolic system of partial differential equations, should allow local regions to advance in time with their own, locally constrained time steps. However, such a scheme can result in violation of the Courant-Friedrichs-Lewy [...]
Thu, Jan 11, 2018
Source: CiteULike Group Cosmo LUTH
(5 Jan 2018)Recent detections of Lyman alpha (Ly$α$) emission from $z>7.5$ galaxies were somewhat unexpected given a dearth of previous non-detections in this era when the intergalactic medium (IGM) is still highly neutral. But these detections were from UV bright galaxies which preferentially live in overdensities which reionize early and [...]
Tue, Jan 09, 2018
Source: CiteULike Group Cosmo LUTH
(5 Jan 2018)The Initial Mass Function (IMF) for massive galaxies can be constrained by combining stellar dynamics with strong gravitational lensing. However, this method is limited by degeneracies between the density profile of dark matter and the stellar mass-to-light ratio. In this work we reduce this degeneracy by combining weak [...]
Tue, Jan 09, 2018
Source: CiteULike Group Cosmo LUTH
(5 Jan 2018)In this paper we study the statistical properties of weak lensing peaks in light-cones generated from numerical simulations. We focus on interacting Dark Energy cosmological models, characterised by a coupling term between dark energy and dark matter which allows us to study in detail how such an interaction [...]
Tue, Jan 09, 2018
Source: CiteULike Group Cosmo LUTH
Monthly Notices of the Royal Astronomical Society (27 Dec 2017), doi:10.1093/mnras/stx3149We study the clustering of the highest-z galaxies (from ~ $0.1$ to a few tens Mpc scales) using the BLUETIDES simulation and compare it to current observational constraints from Hubble legacy and Hyper Suprime Cam (HSC) fields (at $z=6-7.2$). With [...]
Fri, Dec 29, 2017
Source: CiteULike Group Cosmo LUTH
(19 Dec 2017)We present GAMER-2, a GPU-accelerated adaptive mesh refinement (AMR) code for astrophysics. It provides a rich set of features, including adaptive time-stepping, several hydrodynamic schemes, magnetohydrodynamics, self-gravity, particles, star formation, chemistry and radiative processes with GRACKLE, data analysis with yt, and memory pool for efficient object allocation. GAMER-2 [...]
Wed, Dec 20, 2017
Source: CiteULike Group Cosmo LUTH
(18 Dec 2017)We investigate how the nature of the galaxies that reionized the Universe affects the duration of reionization. We contrast two models: one in which galaxies on the faint side of the luminosity function dominate the ionizing emissivity, and a second in which the galaxies on the bright side [...]
Wed, Dec 20, 2017
Source: CiteULike Group Cosmo LUTH
(15 Dec 2017)While low mass, star forming galaxies are often considered as the primary driver of reionization, their actual contribution to the cosmic ultraviolet background is still uncertain, mostly because the escape fraction of ionizing photons is only poorly constrained. Theoretical studies have shown that efficient supernova feedback is a [...]
Tue, Dec 19, 2017
Source: CiteULike Group Cosmo LUTH
(15 Dec 2017)The long timescale evolution of a self-gravitating system is generically driven by two-body encounters. In many cases, the motion of the particles is primarily governed by the mean field potential. When this potential is integrable, particles move on nearly fixed orbits, which can be described in terms of [...]
Tue, Dec 19, 2017
Source: CiteULike Group Cosmo LUTH
(11 Dec 2017)Feedback by Active Galactic Nuclei is often divided into quasar and radio mode, powered by radiation or radio jets, respectively. Both are fundamental in galaxy evolution, especially in late-type galaxies, as shown by cosmological simulations and observations of jet-ISM interactions in these systems. We compare AGN feedback by [...]
Wed, Dec 13, 2017
Source: CiteULike Group Cosmo LUTH
(11 Dec 2017)We trace the specific star formation rate (sSFR) of massive star-forming galaxies ($\gtrsim\!10^10\,\mathcalM_odot$) from $z∼2$ to 7. Our method is substantially different from previous analyses, as it does not rely on direct estimates of star formation rate, but on the differential evolution of the galaxy stellar mass function [...]
Wed, Dec 13, 2017
Source: CiteULike Group Cosmo LUTH
(11 Dec 2017)The smallest satellites of the Milky Way ceased forming stars during the epoch of reionization and thus provide archaeological access to galaxy formation at $z>6$. Numerical studies of these ultra-faint dwarf galaxies (UFDs) require expensive cosmological simulations with high mass resolution that are carried out down to $z=0$. [...]
Wed, Dec 13, 2017
Source: CiteULike Group Cosmo LUTH
Nature (8 Dec 2017), doi:10.1038/nature24629According to the current understanding of cosmic structure formation, the precursors of the most massive structures in the Universe began to form shortly after the Big Bang, in regions corresponding to the largest fluctuations in the cosmic density field. Observing these structures during their period of [...]
Mon, Dec 11, 2017
Source: CiteULike Group Cosmo LUTH
(8 Dec 2017)Galaxies with stellar masses 10^-7 yr^-1 were examined on images of the Hubble Space Telescope Frontier Field Parallels for Abell 2744 and MACS J0416.1-02403. They appear as unresolved "Little Blue Dots" (LBDs). They are less massive and have higher sSFR than "blueberries" studied by yang et al. (2017) [...]
Mon, Dec 11, 2017
Source: CiteULike Group Cosmo LUTH
(7 Dec 2017)A deep understanding of the Epoch of Reionization is still missing in our knowledge of the universe. Awaiting for future probes, which will allow to test the precise evolution of the free electron fraction from redshifts between $z∼eq 6$ and $z∼eq 20$, one could ask which kind of [...]
Mon, Dec 11, 2017
Source: CiteULike Group Cosmo LUTH
(6 Dec 2017)We investigate the cosmological information contained in the cross-correlation between the Integrated Sachs-Wolfe (ISW) of the Cosmic Microwave Background (CMB) anisotropy pattern and galaxy clusters from future wide surveys. Future surveys will provide cluster catalogues with a number of objects comparable with galaxy catalogues currently used for the [...]
Fri, Dec 08, 2017
Source: CiteULike Group Cosmo LUTH
(6 Dec 2017)Recent studies have presented evidence for tension between the constraints on Omega_m and sigma_8 from the cosmic microwave background (CMB) and measurements of large-scale structure (LSS). This tension can potentially be resolved by appealing to extensions of the standard model of cosmology and/or untreated systematic errors in the [...]
Fri, Dec 08, 2017
Source: CiteULike Group Cosmo LUTH
(6 Dec 2017)Analog condensed matter systems present an exciting opportunity to simulate early Universe models in table-top experiments. We consider a recent proposal for an analog condensed matter experiment to simulate the relativistic quantum decay of the false vacuum. In the proposed experiment, two ultra-cold condensates are coupled via a [...]
Fri, Dec 08, 2017
Source: CiteULike Group Cosmo LUTH
(4 Dec 2017)The Baryon Acoustic Oscillations (BAO) refer to the ripples of material density in the Universe. As the most direct density tracers in the universe, galaxies have been commonly used in studies of BAO peak detection. The spatial number density of galaxies, to a certain extent, reflects the distribution [...]
Tue, Dec 05, 2017
Source: CiteULike Group Cosmo LUTH
(4 Dec 2017)In a recent study, using the distribution of galaxies in the north galactic pole of SDSS DR7 region enclosed in a 500$\mpch$ box, we carried out our ELUCID simulation (Wang et al. 2016, ELUCID III). Here we light the dark matter halos and subhalos in the reconstructed [...]
Tue, Dec 05, 2017
Source: CiteULike Group Cosmo LUTH
(4 Dec 2017)The implementation of star formation and stellar feedback in cosmological simulations plays a critical role in shaping the properties of model galaxies. In the first paper of the series, we presented a new method to model star formation as a collection of star clusters. Here, we improve the [...]
Tue, Dec 05, 2017
Source: CiteULike Group Cosmo LUTH
(4 Dec 2017)We investigate the dark matter density profile of the massive elliptical galaxy, NGC 1407, by constructing spherically symmetric Jeans models of its field star and globular cluster systems. Two major challenges in such models are the degeneracy between the stellar mass and the dark matter halo profiles, and [...]
Tue, Dec 05, 2017
Source: CiteULike Group Cosmo LUTH
(3 Dec 2017)We constrain the dark energy equation of state parameter, $w$, using the power spectrum of the thermal Sunyaev-Zeldovich (tSZ) effect. We improve upon previous analyses by taking into account the trispectrum in the covariance matrix and marginalising over the foreground parameters, the correlated noise, the mass bias $B$ [...]
Tue, Dec 05, 2017
Source: CiteULike Group Cosmo LUTH
(30 Nov 2017)We study the dependence of surface mass density profiles, which can be directly measured by weak gravitational lensing, on the orientation of haloes with respect to the line-of-sight direction, using a suite of $N$-body simulations. We find that, when major axes of haloes are aligned with the line-of-sight [...]
Mon, Dec 04, 2017
Source: CiteULike Group Cosmo LUTH
(28 Nov 2017)We contrast predictions for the high-redshift galaxy population and reionization history between Cold Dark Matter (CDM) and an alternative DM model based on the recently developed ETHOS framework (Effective Theory of Structure Formation; Cyr-Racine et al. 2016, Vogelsberger et al. 2016). We focus on an ETHOS model that [...]
Thu, Nov 30, 2017
Source: CiteULike Group Cosmo LUTH
(28 Nov 2017)The next generation of axion direct detection experiments may rule out or confirm axions as the dominant source of dark matter. We develop a general likelihood-based framework for studying the time-series data at such experiments, with a focus on the role of dark-matter astrophysics, to search for signatures [...]
Thu, Nov 30, 2017
Source: CiteULike Group Cosmo LUTH
(27 Nov 2017)We study the shape and kinematics of simulated dwarf galaxy discs in the APOSTLE suite of $Λ$CDM cosmological hydrodynamical simulations. We find that a large fraction of these gas-rich, star-forming discs show weak bars in their stellar component, despite being dark matter-dominated systems. The bar pattern shape and [...]
Wed, Nov 29, 2017
Source: CiteULike Group Cosmo LUTH
(27 Nov 2017)Supermassive black holes (BHs) residing in the brightest cluster galaxies are over-massive relative to the stellar bulge mass or central stellar velocity dispersion of their host galaxy. Since BHs residing at the bottom of the galaxy cluster's potential well may undergo physical processes that are driven by the [...]
Wed, Nov 29, 2017
Source: CiteULike Group Cosmo LUTH
(27 Nov 2017)The galaxy phase-space distribution in galaxy clusters provides insights into the formation and evolution of cluster galaxies, and it can also be used to measure cluster mass profiles. We present a dynamical study based on $∼$3000 passive, non-emission line cluster galaxies drawn from 110 galaxy clusters. The galaxy [...]
Wed, Nov 29, 2017
Source: CiteULike Group Cosmo LUTH
(14 Nov 2017)Ultra-faint galaxies are hosted by small dark matter halos with shallow gravitational potential wells, hence their star formation activity is more sensitive to feedback effects. The shape of the faint-end of the high-$z$ galaxy luminosity function (LF) contains important information on star formation and its interaction with the [...]
Fri, Nov 17, 2017
Source: CiteULike Group Cosmo LUTH
(16 Nov 2017)We apply four statistical learning methods to a sample of $7941$ galaxies ($z [...]
Fri, Nov 17, 2017
Source: CiteULike Group Cosmo LUTH
(15 Nov 2017)The galaxy pairwise velocity dispersion (PVD) can provide important tests of non-standard gravity and galaxy formation models. We describe measurements of the PVD of galaxies in the Galaxy and Mass Assembly (GAMA) survey as a function of projected separation and galaxy luminosity. Due to the faint magnitude limit [...]
Thu, Nov 16, 2017
Source: CiteULike Group Cosmo LUTH
(14 Nov 2017)Accurately predicting the demographics of dark matter (DM) substructure is of paramount importance for many fields of astrophysics, including gravitational lensing, galaxy evolution, halo occupation modeling, and constraining the nature of dark matter. Because of its strongly non-linear nature, DM substructure is typically modeled using N-body simulations, which [...]
Thu, Nov 16, 2017
Source: CiteULike Group Cosmo LUTH
(14 Nov 2017)The clustering amplitude of 7143 clusters from the Sloan Digital Sky Survey (SDSS) is found to increase linearly with cluster mass, closely agreeing with the Gaussian random field hypothesis for structure formation. In detail, the observed correlation length exceeds pure cold dark matter (CDM) simulation predictions by $∼eq [...]
Wed, Nov 15, 2017
Source: CiteULike Group Cosmo LUTH
(14 Nov 2017)Using tens of thousands of halos realized in the BAHAMAS and MACSIS simulations produced with a consistent astrophysics treatment that includes AGN feedback, we validate a multi-property statistical model for the stellar and hot gas mass behavior in halos hosting groups and clusters of galaxies. The large sample [...]
Wed, Nov 15, 2017
Source: CiteULike Group Cosmo LUTH
(9 Nov 2017)We investigate the evolution of the cosmic star formation rate density (SFRD) from redshift z=20 to z=0 and compare it with the observational one by Madau and Dickinson derived from recent compilations of UV and IR data. The theoretical SFRD(z) and its evolution are obtained using a simple [...]
Fri, Nov 10, 2017
Source: CiteULike Group Cosmo LUTH
(7 Nov 2017), doi:10.1051/0004-6361/201731431We present the deepest study to date of the Lya luminosity function (LF) in a blank field using blind integral field spectroscopy from MUSE. We constructed a sample of 604 Lya emitters (LAEs) across the redshift range 2.91 < z < 6.64 using automatic detection software in [...]
Fri, Nov 10, 2017
Source: CiteULike Group Cosmo LUTH
(6 Nov 2017)We compare the sizes and luminosities of 307 faint z=6-8 sources revealed by the Hubble Frontier Fields (HFF) program with sources in the nearby universe. Making use of the latest lensing models and data from the first four HFF clusters with an extensive suite of public lens models, [...]
Wed, Nov 08, 2017
Source: CiteULike Group Cosmo LUTH
(30 Oct 2017)We present an analysis of all prime HST legacy fields spanning >800 arcmin^2 for the search of z~10 galaxy candidates and the study of their UV luminosity function (LF). In particular, we present new z~10 candidates selected from the full Hubble Frontier Field (HFF) dataset. Despite the addition [...]
Fri, Nov 03, 2017
Source: CiteULike Group Cosmo LUTH
(1 Nov 2017)We combine Dark Energy Survey Year 1 clustering and weak lensing data with Baryon Acoustic Oscillations (BAO) and Big Bang Nucleosynthesis (BBN) experiments to constrain the Hubble constant. Assuming a flat $Λ$CDM model with minimal neutrino mass ($∑ m_ν = 0.06$ eV) we find $H_0=67.2^+1.2_-1.0$ km/s/Mpc (68% CL). [...]
Thu, Nov 02, 2017
Source: CiteULike Group Cosmo LUTH