Arxiv Papers

Last entries in the CiteULike library

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

Earlier
(4 Dec 2018) We derive cosmological constraints using a galaxy cluster sample selected from the 2500 deg$^2$ SPT-SZ survey. The sample spans the redshift range $0.25 [...]
Thu, Dec 06, 2018
Source: CiteULike Group Cosmo LUTH
(30 Nov 2018) We report the detection of CO(2-1) line emission from a Lyman Break Galaxy at $z∼5.7$ with the VLA. The CO line luminosity implies a massive molecular gas reservoir of $(1.30.3)(α_ CO/4.5\,M_odot$ (K km s$^-1$ pc$^2)^-1)10^11\,M_odot$, suggesting low star formation efficiency, with a gas depletion timescale of order [...]
Tue, Dec 04, 2018
Source: CiteULike Group Cosmo LUTH
(30 Nov 2018) Several lines of evidence suggest that as dark matter haloes grow their scale radius increases, and also the density in their central region drops. Major mergers seem an obvious mechanism to explain both these phenomena, and the resulting patterns in the concentration-mass-redshift relation. To test this possibility, [...]
Mon, Dec 03, 2018
Source: CiteULike Group Cosmo LUTH
(30 Nov 2018) The structural properties of individual dark matter halos, including shape, spin, concentration and substructure, are linked to the halo's growth history, but the exact connection between the two is unclear. One open question, in particular, is the effect of major mergers on halo structure. We have performed [...]
Mon, Dec 03, 2018
Source: CiteULike Group Cosmo LUTH
(29 Nov 2018) Traditional cosmological hydrodynamics simulations fail to spatially resolve the circumgalatic medium (CGM), the reservoir of tenuous gas surrounding a galaxy and extending to its virial radius. We introduce the technique of Enhanced Halo Resolution (EHR), enabling more realistic physical modeling of the simulated CGM by consistently forcing [...]
Mon, Dec 03, 2018
Source: CiteULike Group Cosmo LUTH
(27 Nov 2018) Cosmic Dawn II (CoDa II) is a new, fully-coupled radiation-hydrodynamics simulation of cosmic reionization and galaxy formation and their mutual impact, to redshift z < 6. With $4096^3$ particles and cells in a 94 Mpc box, it is large enough to model global reionization and its feedback [...]
Thu, Nov 29, 2018
Source: CiteULike Group Cosmo LUTH
(26 Nov 2018) We perform a series of cosmological hydrodynamic simulations to investigate the effects of non-gravitational dark matter (DM) interactions on the intergalactic medium (IGM). In particular, we use the ETHOS framework (Cyr-Racine et al. 2016; Vogelsberger et al. 2016) to compare statistics of the Lyman-$α$ forest in cold [...]
Wed, Nov 28, 2018
Source: CiteULike Group Cosmo LUTH
(26 Nov 2018) We use cosmological hydrodynamical galaxy formation simulations from the NIHAO project to investigate the impact of the threshold for star formation on the response of the dark matter (DM) halo to baryonic processes. The fiducial NIHAO threshold, $n=10\, cm^-3$, results in strong expansion of the DM [...]
Wed, Nov 28, 2018
Source: CiteULike Group Cosmo LUTH
(23 Nov 2018) We present here a three-dimesional hydrodynamical simulation for star formation. Our aim is to explore the effect of the metal-line cooling on the thermodynamics of the star-formation process. We explore the effect of changing the metallicty of the gas from $Z/Z_odot=10^-4$ to $Z/Z_odot=10^-2$. Furthermore, we explore the [...]
Mon, Nov 26, 2018
Source: CiteULike Group Cosmo LUTH
(22 Nov 2018) Low mass galaxies are expected to be dark matter dominated even within their centrals. Recently two observations reported two dwarf galaxies in group environment with very little dark matter in their centrals. We explore the population and origins of dark matter deficit galaxies (DMDGs) in two state-of-the-art [...]
Mon, Nov 26, 2018
Source: CiteULike Group Cosmo LUTH
(21 Nov 2018) There is a correlation between bulge mass of the three main galaxies of the Local Group (LG), i.e. M31, Milky Way (MW), and M33, and the number of their dwarf spheroidal galaxies. A similar correlation has also been reported for spiral galaxies with comparable luminosities outside the [...]
Mon, Nov 26, 2018
Source: CiteULike Group Cosmo LUTH
(15 Nov 2018) Correlations between the radio continuum, infrared and CO emission are known to exist for several types of galaxies and across several orders of magnitude. However, the low-mass, low-luminosity and low-metallicity regime of these correlations is not well known. A sample of metal-rich and metal-poor dwarf galaxies from [...]
Mon, Nov 19, 2018
Source: CiteULike Group Cosmo LUTH
(15 Nov 2018) The degeneracy between disc and halo contributions in spiral galaxy rotation curves makes it difficult to obtain a full understanding of the distribution of baryons and dark matter in disc galaxies like our own Milky Way. Using mock data, we study how constraints on dark matter profiles [...]
Mon, Nov 19, 2018
Source: CiteULike Group Cosmo LUTH
(14 Nov 2018) We describe and test a new numerical method to solve the Schrodinger equation in self-gravitating systems, e.g. Bose-Einstein condensates or 'fuzzy'/ultra-light dark matter. The method is a finite-volume Godunov scheme with stable, higher-order accurate gradient estimation, based on a generalization of recent mesh-free finite-mass Godunov methods. It [...]
Thu, Nov 15, 2018
Source: CiteULike Group Cosmo LUTH
(13 Nov 2018) Simulating the dust content of galaxies and their surrounding gas is challenging due to the wide range of physical processes affecting the dust evolution. Here we present cosmological hydrodynamical simulations of a cluster of galaxies, $M_\text200,crit=6 10^14\, Modot$, including a novel dust model for the moving [...]
Thu, Nov 15, 2018
Source: CiteULike Group Cosmo LUTH
(12 Nov 2018) We perform radiation hydrodynamical simulations of protostellar collapse in spherical symmetry, with a special focus on very low-mass objects, i.e. brown dwarfs and sub-brown dwarfs. The inclusion of a realistic equation of state that includes the effect of hydrogen dissociation allows for a modeling of the complete [...]
Tue, Nov 13, 2018
Source: CiteULike Group Cosmo LUTH
(8 Nov 2018) At intermediate and high redshifts, measurements of galaxy star-formation rates are usually based on rest-frame ultraviolet (UV) data. A correction for dust attenuation, A_UV, is needed for these measurements. This correction is typically inferred from UV spectral slopes (beta) using an equation known as "Meurer's Relation." In [...]
Mon, Nov 12, 2018
Source: CiteULike Group Cosmo LUTH
(8 Nov 2018) Parametric models for galaxy star-formation histories (SFHs) are widely used, though they are known to impose strong priors on physical parameters. This has consequences for measurements of the galaxy stellar-mass function (GSMF), star-formation-rate density (SFRD) and star-forming main sequence (SFMS). We investigate the effects of the exponentially [...]
Mon, Nov 12, 2018
Source: CiteULike Group Cosmo LUTH
(5 Nov 2018) Galaxies are generally found to follow a relation between their size and luminosity, such that luminous galaxies typically have large sizes. The recent identification of a significant population of galaxies with large sizes but low luminosities ("ultra diffuse galaxies", or UDGs) raises the question whether the inverse [...]
Mon, Nov 12, 2018
Source: CiteULike Group Cosmo LUTH
(7 Nov 2018) We use a simple cosmological model with two parameters $(A_s, n_s)$ to illustrate the impact of using Halofit on error forecast based on Fisher information matrix for a $h^-3 Gpc^3$ volume survey. We show that Halofit fails to reproduce well the derivatives of the power spectrum with [...]
Thu, Nov 08, 2018
Source: CiteULike Group Cosmo LUTH
(31 Oct 2018) We study nonlinear response of spinning dark matter (DM) halos to dynamic and secular evolution of stellar bars in the embedded galactic disks, using high-resolution numerical simulations. For a sequence of halos with the cosmological spin parameter $λ=0-0.09$, we analyze evolution of induced DM bars amplitude and [...]
Fri, Nov 02, 2018
Source: CiteULike Group Cosmo LUTH
(31 Oct 2018) Cosmological simulations are reaching the resolution necessary to study ultra-faint dwarf galaxies. Observations indicate that in small populations, the stellar initial mass function (IMF) is not fully populated; rather, stars are sampled in a way that can be approximated as coming from an underlying probability density function. [...]
Fri, Nov 02, 2018
Source: CiteULike Group Cosmo LUTH
(29 Oct 2018) We present a new empirical relation between galaxy dark matter halo mass ($ M_halo$) and the velocity along the flat portion of the rotation curve ($ V_flat$), derived from 120 late-type galaxies from the SPARC database. The orthogonal scatter in this relation is comparable to the observed [...]
Wed, Oct 31, 2018
Source: CiteULike Group Cosmo LUTH
(30 Oct 2018) Abundance matching between galaxies and halos has proven to be an informative technique, less dependent on detailed physical approximations than some other methods. We extend the discussion to the dwarf galaxies realm and to the study of the alternative hypothesis that the dark matter is composed of [...]
Wed, Oct 31, 2018
Source: CiteULike Group Cosmo LUTH
(29 Oct 2018) The existence of ultra-faint dwarf (UFD) galaxies highlights the need to push our theoretical understanding of galaxies to extremely low mass. Using two identical high-resolution, fully cosmological simulations of dwarf galaxies, we examine the formation of dwarf galaxies and their UFD satellites. The simulations have identical initial [...]
Wed, Oct 31, 2018
Source: CiteULike Group Cosmo LUTH
(23 Oct 2018)We study the accuracy with which cosmological parameters can be determined from real space power spectrum of matter density contrast at weakly nonlinear scales using analytical approaches. From power spectra measured in $N$-body simulations and using Markov chain Monte-Carlo technique, the best fitting cosmological input parameters are determined [...]
Thu, Oct 25, 2018
Source: CiteULike Group Cosmo LUTH
(23 Oct 2018)It is well established that the central deficit of dark matter (DM) observed in many dwarf galaxies disagrees with the cuspy DM haloes predicted in the collision-less and cold DM (CDM) model. Plausible solutions to this problem are based on an effective energy deposition into the central halo [...]
Thu, Oct 25, 2018
Source: CiteULike Group Cosmo LUTH
(23 Oct 2018)We present new mass estimates and cumulative mass profiles (CMPs) with Bayesian credible regions for the Milky Way (MW) Galaxy, given the kinematic data of globular clusters as provided by (1) the Gaia DR2 collaboration and the HSTPROMO team, and (2) the new catalog in Vasiliev (2018). We [...]
Thu, Oct 25, 2018
Source: CiteULike Group Cosmo LUTH
(22 Oct 2018) We apply our recently proposed "quadratic genetic modification" approach to generating and testing the effects of alternative mass accretion histories for a single $Λ$CDM halo. The goal of the technique is to construct different formation histories, varying the overall contribution of mergers to the fixed final mass. [...]
Wed, Oct 24, 2018
Source: CiteULike Group Cosmo LUTH
(22 Oct 2018) We explore a class of simple non-equilibrium star formation models within the framework of a feedback-regulated model of the ISM, applicable to kiloparsec-scale resolved star formation relations (e.g. Kennicutt-Schmidt). Combining a Toomre-Q-dependent local star formation efficiency per free-fall time with a model for delayed feedback, we are [...]
Wed, Oct 24, 2018
Source: CiteULike Group Cosmo LUTH
(15 Oct 2018)We investigate the structure of galaxies formed in a suite of high-resolution cosmological simulations. Consistent with observations of high-redshift galaxies, our simulated galaxies show irregular, prolate shapes with thick stellar disks, which are dominated by turbulent motions instead of rotation. Yet molecular gas and young stars are restricted [...]
Wed, Oct 17, 2018
Source: CiteULike Group Cosmo LUTH
The Astrophysical Journal, Vol. 864, No. 1. (21 Aug 2018), L14, doi:10.3847/2041-8213/aada48We present HI spectral line and optical broadband images of the nearby low surface brightness dwarf galaxy KDG215. The HI images, acquired with the Karl G. Jansky Very Large Array (VLA), reveal a dispersion dominated ISM with only weak [...]
Mon, Oct 15, 2018
Source: CiteULike Group Cosmo LUTH
(4 Oct 2018)Halo bias is the main link between the matter distribution and dark matter halos. In its simplest form, halo bias is determined by halo mass, but there are known additional dependencies on other halo properties which are of consequence for accurate modeling of galaxy clustering. Here we present [...]
Mon, Oct 08, 2018
Source: CiteULike Group Cosmo LUTH
(20 Sep 2018)Molecular clouds exhibit lognormal probability density functions (PDF) of mass densities, which are thought to arise as a consequence of isothermal, supersonic turbulence. Star formation is then widely assumed to occur in perturbations in which gravitational collapse is faster than the rate of change due to turbulent motions. [...]
Mon, Sep 24, 2018
Source: CiteULike Group Cosmo LUTH
(20 Sep 2018)Dark matter may be composed of light bosons, $m_b ∼ 10^-22\, \mathrmeV$, with a de Broglie wavelength $λ ∼ 1 \,\mathrmkpc$ in typical galactic potentials. Such `fuzzy' dark matter (FDM) behaves like cold dark matter (CDM) on much larger scales than the de Broglie wavelength, but may resolve [...]
Fri, Sep 21, 2018
Source: CiteULike Group Cosmo LUTH
(5 Oct 2018)We present a full data analysis of the Brightest of Reionizing Galaxies Survey (BoRG[z9]) pure-parallel HST imaging observations in Cycle 22. The medium deep exposures with five HST/WFC3IR+UVIS filter bands from 79 independent sightlines (~370 arcmin^2) provide the least biased determination of number density for z>9 bright galaxies [...]
Fri, Sep 21, 2018
Source: CiteULike Group Cosmo LUTH
(19 Sep 2018)The presence of spectroscopically confirmed Balmer breaks in galaxy spectral energy distributions (SEDs) at $z>9$ provides one of the best probes of the assembly history of the first generations of stars in our Universe. Recent observations of the gravitationally lensed source, MACS 1149_JD1 (JD1), indicate that significant amounts [...]
Thu, Sep 20, 2018
Source: CiteULike Group Cosmo LUTH
Monthly Notices of the Royal Astronomical Society, Vol. 480, No. 3. (24 Sep 2018), pp. 4265-4272, doi:10.1093/mnras/sty2123We argue that an increased temperature in star-forming clouds alters the stellar initial mass function to be more bottom-light than in the Milky Way. At redshifts $z \gtrsim 6$, heating from the cosmic microwave [...]
Wed, Sep 12, 2018
Source: CiteULike Group Cosmo LUTH
Monthly Notices of the Royal Astronomical Society: Letters (5 Sep 2018), doi:10.1093/mnrasl/sly164Elucidating the particle physics nature of dark matter (DM) is one of the great challenges in modern science. The current lack of any direct DM detections in the laboratory heightens the need for astrophysical constraints, extending the search to [...]
Fri, Sep 07, 2018
Source: CiteULike Group Cosmo LUTH
(5 Sep 2018)Forthcoming large-scale spectroscopic surveys will soon provide data on thousands of galaxy clusters. It is important that the systematics of the various mass estimation techniques are well understood and calibrated. We compare three different dynamical mass estimators using the C-EAGLE galaxy clusters, a set of high resolution simulations [...]
Fri, Sep 07, 2018
Source: CiteULike Group Cosmo LUTH
(21 Aug 2018)We have examined dust emission in galaxy clusters at millimeter wavelengths using the Planck $857 \, GHz$ map to constrain the model based on Herschel observations that was used in studies for the Cosmic ORigins Explorer (CORE) mission concept. By stacking the emission from Planck-detected clusters, we [...]
Wed, Aug 22, 2018
Source: CiteULike Group Cosmo LUTH
(20 Aug 2018)Gravitational potential fluctuations driven by bursty star formation can kinematically 'heat up' dark matter at the centres of dwarf galaxies. A key prediction of such models is that, at a fixed dark matter halo mass, dwarfs with more extended star formation will have lower central densities than those [...]
Wed, Aug 22, 2018
Source: CiteULike Group Cosmo LUTH
(13 Aug 2018)We determine the thermal evolution of the intergalactic medium (IGM) over $3\, \mathrmGyr$ of cosmic time $1.8 [...]
Wed, Aug 15, 2018
Source: CiteULike Group Cosmo LUTH
(10 Aug 2018)A standard prediction of galaxy formation theory is that the ionizing background suppresses galaxy formation in haloes with peak circular velocities smaller than Vpeak ~ 20 km/s, rendering the majority of haloes below this scale completely dark. We use a suite of cosmological zoom simulations of Milky Way-like [...]
Tue, Aug 14, 2018
Source: CiteULike Group Cosmo LUTH
(10 Aug 2018)We directly compare predictions of dwarf galaxy properties in a semi-analytic model (SAM) with those extracted from a high-resolution hydrodynamic simulation. We focus on galaxies with halo masses of 1e9 [...]
Mon, Aug 13, 2018
Source: CiteULike Group Cosmo LUTH
(1 Aug 2018)Effective stellar feedback is used in models of galaxy formation to regulate star formation and drive realistic galaxy evolution. Models typically include energy injection from supernovae as the dominant form of stellar feedback, often in some form of sub-grid recipe. However, it has been recently suggested that pre-SN [...]
Fri, Aug 03, 2018
Source: CiteULike Group Cosmo LUTH
(23 Jul 2018)It has recently been shown that the abundance of cold neutral gas may follow a similar evolution as the star formation history. This is physically motivated, since stars form out of this component of the neutral gas and if the case, would resolve the longstanding issue that there [...]
Wed, Jul 25, 2018
Source: CiteULike Group Cosmo LUTH
(18 Jul 2018)The cosmological utility of galaxy cluster catalogues is primarily limited by our ability to calibrate the relation between halo mass and observable mass proxies such as cluster richness, X-ray luminosity or the Sunyaev-Zeldovich signal. Projection effects are a particularly pernicious systematic effect that can impact observable mass proxies; [...]
Fri, Jul 20, 2018
Source: CiteULike Group Cosmo LUTH
(5 Jul 2018)Recent hydrodynamical simulations predict that stellar feedback in intermediate mass galaxies (IMGs) can drive strong fluctuations in structure (e.g., half-light radius, $R_e$). This process operates on timescales of only a few hundred Myr and persists even at late cosmic times. One prediction of this quasi-periodic, galactic-scale "breathing" is [...]
Mon, Jul 09, 2018
Source: CiteULike Group Cosmo LUTH
(4 Jul 2018)We use a sample of 23 galaxy clusters to test the predictions of an Emergent Gravity (EG) as alternative to dark matter. Our sample has both weak-lensing inferred total mass profiles as well as X-ray inferred baryonic gas mass profiles. Using nominal assumptions about the weak-lensing and X-ray [...]
Thu, Jul 05, 2018
Source: CiteULike Group Cosmo LUTH