Arxiv Papers

Last entries in the CiteULike library

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

Earlier
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
(3 Jul 2018)The tentative detection by the EDGES experiment of a global 21-cm absorption trough centered at redshift 17 opens up the opportunity to study the birth of the first luminous sources, the intensity of radiation backgrounds at cosmic dawn, the thermal and ionization history of the young intergalactic medium. [...]
Thu, Jul 05, 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
Publications of the Astronomical Society of Japan, Vol. 70, No. 3. (27 Jun 2018), doi:10.1093/pasj/psy040Gas motions in galaxy clusters play important roles in determining the properties of the intracluster medium (ICM) and in the constraint of cosmological parameters via X-ray and Sunyaev-Zel'dovich effect observations of galaxy clusters. The Hitomi measurements [...]
Thu, Jun 28, 2018
Source: CiteULike Group Cosmo LUTH
(20 Jun 2018)According to star formation histories (SFHs), Local Group dwarf galaxies can be broadly classified in two types: those forming most of their stars before $z=2$ ($ fast$) and those with more extended SFHs ($ slow$). The most precise SFHs are usually derived from deep but not very spatially [...]
Thu, Jun 21, 2018
Source: CiteULike Group Cosmo LUTH
(20 Jun 2018)We use the sky-average spectrum measured by EDGES High-Band ($90-190$ MHz) to constrain parameters of early galaxies independent of the absorption feature at $78$~MHz reported by Bowman et al. (2018). These parameters represent traditional models of cosmic dawn and the epoch of reionization produced with the 21cmFAST simulation [...]
Thu, Jun 21, 2018
Source: CiteULike Group Cosmo LUTH
(19 Jun 2018)We use the photon flux and absorption tracer algorithm presented in Katz et al. 2018, to characterise the contribution of haloes of different mass and stars of different age and metallicity to the reionization of the Universe. We employ a suite of cosmological multifrequency radiation hydrodynamics AMR simulations [...]
Thu, Jun 21, 2018
Source: CiteULike Group Cosmo LUTH
(21 May 2018)The 21-cm signal in the vicinity of the first stars is expected to reflect properties of the first stars. In this study we pay special attention to tracing the time evolution of the ionizing photons' escape fraction, which affects the distribution of neutral hydrogen, by performing radiation hydrodynamics [...]
Tue, May 22, 2018
Source: CiteULike Group Cosmo LUTH
(13 May 2018)I describe a fast algorithm for the identification of connected sets of points where the point-wise connections are determined by a fixed spatial distance - a task commonly referred to in the cosmological simulation community as Friends-of-Friends (FOF) group finding. This technique sorts particles into fine cells sufficiently [...]
Thu, May 17, 2018
Source: CiteULike Group Cosmo LUTH
(1 May 2018)Mass estimators are a key tool to infer the distribution of dark matter in pressure-supported systems like dwarf spheroidal galaxies (dSphs). We construct an estimator for enclosed masses based on the virial theorem which is insensitive to anisotropy in the velocity dispersion and tailored to yield masses with [...]
Thu, May 03, 2018
Source: CiteULike Group Cosmo LUTH
(23 Apr 2018)We present a search for nuclear X-ray emission in the Brightest Cluster Galaxies (BCGs) of a sample of groups and clusters of galaxies extracted from the Chandra archive. The exquisite angular resolution of Chandra allows us to obtain robust photometry at the position of the BCG, and to [...]
Wed, Apr 25, 2018
Source: CiteULike Group Cosmo LUTH
(20 Apr 2018)We investigate the performances of Apache Spark, a cluster computing framework, for analyzing data from future LSST-like galaxy surveys. Apache Spark attempts to address big data problems have hitherto proved successful in the industry, but its main use is often limited to naively structured data. We show how [...]
Mon, Apr 23, 2018
Source: CiteULike Group Cosmo LUTH
(19 Apr 2018)We utilize the hydrodynamic and N-body code GIZMO, coupled with newly developed sub-grid Legacy models for Population~III (Pop~III) and Population~II (Pop~II), specifically designed for meso-scale cosmological volume simulations, to study the legacy of star formation in the pre-reionization Universe. We find that the Pop~II star formation rate density [...]
Mon, Apr 23, 2018
Source: CiteULike Group Cosmo LUTH
(16 Apr 2018)The expansion history of the Universe can be constrained in a cosmology-independent way by measuring the differential age evolution of cosmic chronometers. This yields a measurement of the Hubble parameter as a function of redshift. The most reliable cosmic chronometers known so far are extremely massive and passively [...]
Wed, Apr 18, 2018
Source: CiteULike Group Cosmo LUTH
(11 Apr 2018)It was recently proposed that the globular cluster system of the very low surface-brightness galaxy NGC1052-DF2 is dynamically very cold, leading to the conclusion that this dwarf galaxy has little or no dark matter. Here, we show that a robust statistical measure of the velocity dispersion of the [...]
Fri, Apr 13, 2018
Source: CiteULike Group Cosmo LUTH
(11 Apr 2018)The virial masses of ultra-diffuse galaxies (UDGs) have been estimated using the kinematics and abundance of their globular cluster populations, leading to disparate results. Some studies conclude that UDGs reside in massive dark matter halos while others, controversially, argue for the existence of UDGs with no dark matter [...]
Fri, Apr 13, 2018
Source: CiteULike Group Cosmo LUTH
(12 Apr 2018)We analyze the Illustris-1 hydrodynamical cosmological simulation to explore the stellar velocity dispersion of quiescent galaxies as an observational probe of dark matter halo velocity dispersion and mass. Stellar velocity dispersion is proportional to dark matter halo velocity dispersion for both central and satellite galaxies. The dark matter [...]
Fri, Apr 13, 2018
Source: CiteULike Group Cosmo LUTH
(11 Apr 2018)We examine the results from the Experiment to Detect the Global Epoch of Reionization Signature (EDGES), which has recently claimed the detection of a strong absorption in the 21 cm hyperfine transition line of neutral hydrogen, at redshifts demarcating the early stages of star formation. More concretely, we [...]
Thu, Apr 12, 2018
Source: CiteULike Group Cosmo LUTH
(29 Mar 2018)Winds are predicted to be ubiquitous in low-mass, actively star-forming galaxies. Observationally, winds have been detected in relatively few local dwarf galaxies, with even fewer constraints placed on their timescales. Here, we compare galactic outflows traced by diffuse, soft X-ray emission from Chandra Space Telescope archival observations to [...]
Mon, Apr 02, 2018
Source: CiteULike Group Cosmo LUTH
(24 Mar 2018)As part of our long-term campaign to understand how cold streams feed massive galaxies at high redshift, we study the Kelvin-Helmholtz instability (KHI) of a supersonic, cold, dense gas stream as it penetrates through a hot, dilute circumgalactic medium (CGM). A linear analysis (Paper I) showed that, for [...]
Wed, Mar 28, 2018
Source: CiteULike Group Cosmo LUTH
(26 Mar 2018)With the Hubble Frontier Fields program, gravitational lensing has provided a powerful way to extend the study of the ultraviolet luminosity function (LF) of galaxies at $z ∼ 6$ down to unprecedented magnitude limits. At the same time, significant discrepancies between different studies were found at the very [...]
Wed, Mar 28, 2018
Source: CiteULike Group Cosmo LUTH
(20 Mar 2018)We present a detailed study of the integrated total hydrostatic mass profiles of the five most massive ($M_500 > 5 10^14 M_odot$) galaxy clusters selected at z$∼$1 via the Sunyaev-Zel'dovich effect. These objects represent an ideal laboratory to test our models in a mass regime where structure [...]
Wed, Mar 21, 2018
Source: CiteULike Group Cosmo LUTH
(16 Mar 2018)Standard present day large-scale structure (LSS) analyses make a major assumption in their Bayesian parameter inference --- that the likelihood has a Gaussian form. For summary statistics currently used in LSS, this assumption, even if the underlying density field is Gaussian, cannot be correct in detail. We investigate [...]
Tue, Mar 20, 2018
Source: CiteULike Group Cosmo LUTH
(14 Mar 2018)We focus on exploring the metal enrichment of the intergalactic medium (IGM) in Cold and Warm (1.5 and 3 keV) Dark Matter (DM) cosmologies, and the constraints this yields on the DM particle mass, using a semi-analytic model, Delphi, that jointly tracks the Dark Matter and baryonic assembly [...]
Fri, Mar 16, 2018
Source: CiteULike Group Cosmo LUTH
(14 Mar 2018)The evolution of galaxies is governed by equations with chaotic solutions: gravity and compressible hydrodynamics. While this micro-scale chaos and stochasticity has been well studied, it is poorly understood how it couples to macro-scale properties examined in simulations of galaxy formation. In this paper, we show how perturbations [...]
Fri, Mar 16, 2018
Source: CiteULike Group Cosmo LUTH
(8 Mar 2018)We investigate the evolution of axis ratios of triaxial haloes using the phase space description of triaxial collapse. In this formulation, the evolution of the triaxial ellipsoid is described in terms of the dynamics of eigenvalues of three important tensors: the Hessian of the gravitational potential, the tensor [...]
Fri, Mar 09, 2018
Source: CiteULike Group Cosmo LUTH
(6 Mar 2018)We investigate the dynamical evolution of galaxies in groups with different formation epochs. Galaxy groups have been selected to be in different dynamical states, namely dynamically old and dynamically young, which reflect their early and late formation times, respectively, based on their halo mass assembly. Brightest galaxies in [...]
Thu, Mar 08, 2018
Source: CiteULike Group Cosmo LUTH
(28 Feb 2018)We have developed a modular semi-numerical code that computes the time and spatially dependent ionization of neutral hydrogen (HI), neutral (HeI) and singly ionized helium (HeII) in the intergalactic medium (IGM). The model accounts for recombinations and provides different descriptions for the photoionization rate that are used to [...]
Fri, Mar 02, 2018
Source: CiteULike Group Cosmo LUTH
(21 Feb 2018)The recent discovery of dusty galaxies well into the Epoch of Reionization (redshift $z>6$) poses challenging questions about the properties of the interstellar medium in these pristine systems. By combining state-of-the-art hydrodynamic and dust radiative transfer simulations, we address these questions focusing on the recently discovered dusty galaxy [...]
Fri, Feb 23, 2018
Source: CiteULike Group Cosmo LUTH
(20 Feb 2018)The mass of galaxy clusters is not a direct observable, nonetheless it is commonly used to probe cosmological models. Based on the combination of all main cluster observables, that is, the X-ray emission, the thermal Sunyaev-Zel'dovich (SZ) signal, the velocity dispersion of the cluster galaxies, and gravitational lensing, [...]
Wed, Feb 21, 2018
Source: CiteULike Group Cosmo LUTH
(19 Feb 2018)The most luminous galaxies at high-redshift are generally considered to be hosted in massive dark-matter halos of comparable number density, hence residing at the center of overdensities/protoclusters. We assess the validity of this assumption by investigating the clustering around the brightest galaxies populating the cosmic web at redshift [...]
Wed, Feb 21, 2018
Source: CiteULike Group Cosmo LUTH
(19 Feb 2018)We present the reconstructed evolution of rest-frame ultra-violet (UV) luminosities of the most massive Milky Way dwarf spheroidal satellite galaxy, Fornax, and its five globular clusters (GCs) across redshift, based on analysis of the stellar fossil record and stellar population synthesis modeling. We find that (1) Fornax's (proto-)GCs [...]
Wed, Feb 21, 2018
Source: CiteULike Group Cosmo LUTH
(19 Feb 2018)Observations show that star-forming galaxies reside on a tight three-dimensional plane between mass, gas-phase metallicity and star formation rate (SFR), which can be explained by the interplay between metal-poor gas inflows and SFR. However, different metals are released on different time-scales, which may affect this relation. Here, we [...]
Wed, Feb 21, 2018
Source: CiteULike Group Cosmo LUTH