Last entries in the CiteULike library

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

EarlierProbing the nature of Dark Matter through the metal enrichment of the intergalactic medium(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, 2018Source: CiteULike Group Cosmo LUTHChaos and Variance in Galaxy Formation(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, 2018Source: CiteULike Group Cosmo LUTHEvolution of axis ratios from phase space dynamics of triaxial collapse(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, 2018Source: CiteULike Group Cosmo LUTHMerger history of central galaxies in Semi-Analytic Models of galaxy formation(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, 2018Source: CiteULike Group Cosmo LUTHThe accuracy of semi-numerical reionization models in comparison with radiative transfer simulations(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, 2018Source: CiteULike Group Cosmo LUTHDusty galaxies in the Epoch of Reionization: simulations(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, 2018Source: CiteULike Group Cosmo LUTHReconstruction of the two-dimensional gravitational potential of galaxy clusters from X-ray and Sunyaev-Zel'dovich measurements(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, 2018Source: CiteULike Group Cosmo LUTHThe Cosmic Web Around The Brightest Galaxies During The Epoch Of Reionization(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, 2018Source: CiteULike Group Cosmo LUTHGlobular Clusters in High-Redshift Dwarf Galaxies: A Case Study from the Local Group(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, 2018Source: CiteULike Group Cosmo LUTHStar-forming galaxies are predicted to lie on a fundamental plane of mass, star formation rate and Î±-enhancement(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, 2018Source: CiteULike Group Cosmo LUTHObscured star-formation in bright z ~ 7 Lyman-break galaxies(15 Feb 2018)We present Atacama Large Millimeter/Submillimeter Array observations of the rest-frame far-infrared (FIR) dust continuum emission of six bright Lyman-break galaxies (LBGs) at $z ∼eq 7$. The average FIR luminosity of the sample is found to be $L_ FIR ∼eq 2 × 10^11\, L_odot$, corresponding to an obscured star-formation [...]Mon, Feb 19, 2018Source: CiteULike Group Cosmo LUTHGravitational Redshifts in Clusters and Voids(14 Feb 2018)Gravitational redshift as a relativistic effect in cosmological objects is investigated. Possible signatures of the gravitational redshift in measurements of satellite galaxies in clusters of galaxies, intracluster gas, as well as galaxies associated with voids are investigated by developing simple theoretical models. In the analysis of the gravitational [...]Thu, Feb 15, 2018Source: CiteULike Group Cosmo LUTHDark-ages Reionization and Galaxy Formation Simulation - XIV. Gas accretion, cooling and star formation in dwarf galaxies at high redshift(12 Feb 2018)We study dwarf galaxy formation at high redshift ($z≥5$) using a suite of high-resolution, cosmological hydrodynamic simulations and a semi-analytic model (SAM). We focus on gas accretion, cooling and star formation in this work by isolating the relevant process from reionization and supernova feedback, which will be further [...]Tue, Feb 13, 2018Source: CiteULike Group Cosmo LUTHCosmological simulation with dust formation and destruction(12 Feb 2018)To investigate the evolution of dust in a cosmological volume, we perform hydrodynamic simulations, in which the enrichment of metals and dust is treated self-consistently with star formation and stellar feedback. We consider dust evolution driven by dust production in stellar ejecta, dust destruction by sputtering, grain growth [...]Tue, Feb 13, 2018Source: CiteULike Group Cosmo LUTHReignition of Star Formation in Dwarf Galaxies(8 Feb 2018)The Local Group hosts a number of star-forming dwarf galaxies that show evidence of periods of little to no star formation. We use a suite of cosmological simulations to study how star formation is reignited in such galaxies. We focus on isolated galaxies at $z=0$ with halo masses [...]Mon, Feb 12, 2018Source: CiteULike Group Cosmo LUTHEnvironmental Quenching of Low-Mass Field Galaxies(8 Feb 2018)In the local Universe, there is a strong division in the star-forming properties of low-mass galaxies, with star formation largely ubiquitous amongst the field population while satellite systems are predominantly quenched. This dichotomy implies that environmental processes play the dominant role in suppressing star formation within this low-mass [...]Mon, Feb 12, 2018Source: CiteULike Group Cosmo LUTHThe Inhomogeneous Reionization Times of Present-day Galaxies(5 Feb 2018)Today's galaxies experienced cosmic reionization at different times in different locations. For the first time, reionization ($50\%$ ionized) redshifts, $z_R$, at the location of their progenitors are derived from new, fully-coupled radiation-hydrodynamics simulation of galaxy formation and reionization at $z > 6$, matched to N-body simulation to z [...]Wed, Feb 07, 2018Source: CiteULike Group Cosmo LUTHUnveiling Galaxy Bias via the Halo Model, KiDS and GAMA(2 Feb 2018)We measure the projected galaxy clustering and galaxy-galaxy lensing signals using the Galaxy And Mass Assembly (GAMA) survey and Kilo-Degree Survey (KiDS) to study galaxy bias. We use the concept of non-linear and stochastic galaxy biasing in the framework of halo occupation statistics to constrain the parameters of [...]Mon, Feb 05, 2018Source: CiteULike Group Cosmo LUTHFirstLight II: Star formation rates of primeval galaxies from z=5-15(31 Jan 2018)In the FirstLight project, we have used ~300 cosmological, zoom-in simulations to determine the star-formation histories of distinct first galaxies with stellar masses between Ms=10^6 and 3 x 10^9 Msun during cosmic dawn (z=5-15). The evolution of the star formation rate (SFR) in each galaxy is complex and [...]Thu, Feb 01, 2018Source: CiteULike Group Cosmo LUTHExploring Simulated Early Star Formation in the Context of the Ultrafaint Dwarf Galaxies(25 Jan 2018)Ultrafaint dwarf galaxies (UFDs) are typically assumed to have simple, stellar populations with star formation ending at reionization. Yet as the observations of these galaxies continue to improve, their star formation histories (SFHs) are revealed to be more complicated than previously thought. In this paper, we study how [...]Mon, Jan 29, 2018Source: CiteULike Group Cosmo LUTHDynamical constraints on the dark matter distribution of the Sculptor dwarf spheroidal from stellar proper motions(22 Jan 2018)We compare the transverse velocity dispersions recently measured within the Sculptor dwarf spheroidal galaxy to the predictions of previously published dynamical models. These provide good fits to the observed number count and velocity dispersion profiles of metal-rich and metal-poor stars both in cored and in cusped potentials. At [...]Thu, Jan 25, 2018Source: CiteULike Group Cosmo LUTHThe SPHINX Cosmological Simulations of the First Billion Years: the Impact of Binary Stars on Reionization(22 Jan 2018)We present the SPHINX suite of cosmological adaptive mesh refinement simulations, the first radiation-hydrodynamical simulations to simultaneously capture large-scale reionization and the escape of ionizing radiation from thousands of resolved galaxies. Our $5$ and $10$ co-moving Mpc volumes resolve haloes down to the atomic cooling limit and model [...]Thu, Jan 25, 2018Source: CiteULike Group Cosmo LUTHEvidence of a non universal stellar Initial Mass Function. Insights from HST optical imaging of 6 Ultra Faint Dwarf Milky Way Satellites(18 Jan 2018)Using deep HST/ACS observations, we demonstrate that the sub-solar stellar initial mass function (IMF) of 6 ultra-faint dwarf Milky Way Satellites (UFDs) is more bottom light than the IMF of the Milky Way disk. Our data have a lower mass limit of about 0.45 M$_odot$, while the upper [...]Mon, Jan 22, 2018Source: CiteULike Group Cosmo LUTHNo Assembly Required: Mergers are Mostly Irrelevant for the Growth of Low-mass Dwarf Galaxies(18 Jan 2018)We investigate the merger histories of isolated dwarf galaxies based on a suite of 15 high-resolution cosmological zoom-in simulations, all with masses of $M_ halo ≈ 10^10\, M_odot$ (and M$_∗∼10^5-10^7\, M_odot$) at $z=0$, from the Feedback in Realistic Environments (FIRE) project. The stellar populations of these dwarf galaxies [...]Mon, Jan 22, 2018Source: CiteULike Group Cosmo LUTHPushing back the limits: detailed properties of dwarf galaxies in a LCDM universe(18 Jan 2018)We present the results of a set of high resolution chemo-dynamical simulations of dwarf galaxies in a $Λ$CDM cosmology. Out of an original 3.4 Mpc$^3$/h$^3$ cosmological box, a sample of 27 systems are zoomed-in from z=70 to z=0. Gas and stellar properties are confronted to the observations in [...]Mon, Jan 22, 2018Source: CiteULike Group Cosmo LUTHBeyond Falsifiability: Normal Science in a Multiverse(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, 2018Source: CiteULike Group Cosmo LUTHConsistent modelling of the meta-galactic UV background and the thermal/ionization history of the intergalactic medium(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, 2018Source: CiteULike Group Cosmo LUTHA Radio Continuum Study of Dwarf Galaxies: 6 cm imaging of Little Things(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, 2018Source: CiteULike Group Cosmo LUTHImpact of Lyman alpha pressure on metal-poor dwarf galaxies(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, 2018Source: CiteULike Group Cosmo LUTHBlueTides simulation: establishing black hole-galaxy relations at high-redshift(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, 2018Source: CiteULike Group Cosmo LUTHCool-Core Clusters : Role of BCG, Star Formation & AGN-Driven Turbulence(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, 2018Source: CiteULike Group Cosmo LUTHOn the Appearance of Thresholds in the Dynamical Model of Star Formation(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, 2018Source: CiteULike Group Cosmo LUTHSemi-Analytic Galaxies - I. Synthesis of environmental and star-forming regulation mechanisms(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, 2018Source: CiteULike Group Cosmo LUTHGalaxy Formation in Sterile Neutrino Dark Matter Models(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, 2018Source: CiteULike Group Cosmo LUTHOn the Schrodinger-Poisson--Vlasov-Poisson correspondence(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, 2018Source: CiteULike Group Cosmo LUTHEnforcing the Courant-Friedrichs-Lewy Condition in Explicitly Conservative Local Time Stepping Schemes(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, 2018Source: CiteULike Group Cosmo LUTHBeacons into the Cosmic Dark Ages: Boosted transmission of Ly$Î±$ from UV bright galaxies at $z \gtrsim 7$(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, 2018Source: CiteULike Group Cosmo LUTHEvidence for radial variations in the stellar mass-to-light ratio of massive galaxies from weak and strong lensing(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, 2018Source: CiteULike Group Cosmo LUTHWeak Lensing Peaks in Simulated Light-Cones: Investigating the Coupling between Dark Matter and Dark Energy(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, 2018Source: CiteULike Group Cosmo LUTHThe clustering of $z > 7$ galaxies: Predictions from the BLUETIDES simulationMonthly 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, 2017Source: CiteULike Group Cosmo LUTHGAMER-2: a GPU-accelerated adaptive mesh refinement code -- accuracy, performance, and scalability(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, 2017Source: CiteULike Group Cosmo LUTHThe duration of reionization constrains the ionizing sources(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, 2017Source: CiteULike Group Cosmo LUTHEscape of ionizing radiation from high redshift dwarf galaxies: role of AGN feedback(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, 2017Source: CiteULike Group Cosmo LUTHRelaxation in self-gravitating systems(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, 2017Source: CiteULike Group Cosmo LUTHAGN Feedback Compared: Jets versus Radiation(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, 2017Source: CiteULike Group Cosmo LUTHAn alternate approach to measure specific star formation rates at 2<z<7(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, 2017Source: CiteULike Group Cosmo LUTHSelecting ultra-faint dwarf candidate progenitors in cosmological N-body simulations at high redshifts(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, 2017Source: CiteULike Group Cosmo LUTHGalaxy growth in a massive halo in the first billion years of cosmic historyNature (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, 2017Source: CiteULike Group Cosmo LUTHLittle Blue Dots in the Hubble Space Telescope Frontier Fields: Precursors to Globular Clusters?(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, 2017Source: CiteULike Group Cosmo LUTHWas there an early reionization component in our universe?(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, 2017Source: CiteULike Group Cosmo LUTH