Related papers: Cosmological Constraints from High-Redshift Damped…
Although quasar absorbers, and in particular Damped Lyman-alpha systems (DLAs) have proven a valuable tool to study the early Universe, their exact nature is so far poorly constrained. It has been suggested that outflows in galaxies might…
We present the measured gas-phase metal column densities in 155 sub-damped Lyman alpha systems (subDLAs) with the aim to investigate the contribution of subDLAs to the chemical evolution of the Universe. The sample was identified within the…
We investigated abundance ratios along the profiles of six high-redshift Damped Lyman-alpha systems, three of them associated with H2 absorption, and derived optical depths in each velocity pixel. The variations of the pixel abundance…
We present the results of a numerical study of a galactic wind model and its implications on the properties of damped Lyman-alpha absorbers (DLAs) using cosmological hydrodynamic simulations. We vary both the wind strength and the internal…
In order to interpret H2 (molecular hydrogen) quasar absorption line observations of damped Ly-alpha systems (DLAs) and sub-DLAs, we model their H2 abundance as a function of dust-to-gas ratio, including H2 self-shielding and dust…
We use cosmological hydrodynamic simulations with stellar feedback from the FIRE project to study the physical nature of Lyman limit systems (LLSs) at z<1. At these low redshifts, LLSs are closely associated with dense gas structures…
We review theoretical approaches to the study of galaxy formation, with emphasis on the role of hydrodynamic simulations in modeling the high redshift galaxy population. We present new predictions for the abundance of star-forming galaxies…
Though observationally rare, damped Lya absorption systems dominate the mass density of neutral gas in the Universe. Eleven high redshift damped Lya systems covering 2.8<z<4.4 were discovered in 26 QSOs from the APM z>4 QSO Survey,…
We test semi-analytic models for galaxy formation with accurate kinematic data of damped Lyman alpha protogalaxies (DLAs) presented in the companion paper I. The models envisage centrifugally supported exponential disks at the centers of…
We present results from a survey of galaxies in the fields of six z>3 Damped Lyman alpha systems (DLAs) using the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). We report a high detection rate of up to ~80% of…
We report on the first Cosmic Origins Spectrograph (COS) observations of damped and sub-damped Lyman-alpha (DLA) systems discovered in a new survey of the gaseous halos of low-redshift galaxies. From observations of 37 sightlines, we have…
Measurements of element abundances in damped Lyman alpha systems are providing new means to investigate the chemical evolution of galaxies, particularly at early times. We review progress in this area, concentrating on recent efforts to…
A model of damped lyman alpha systems is presented based on randomly moving clouds in spherical halos. We use the Press-Schechter model for the abundance of halos, and assume that each halo has a similar population of clouds, with total…
The local power law relationship between the surface densities of neutral hydrogen gas and star formation rate (SFR) can be used to explore the SFR properties of damped Lyman alpha (DLA) systems at higher redshift. We find that while the…
We report evidence for a bimodality in damped Ly systems (DLAs). Using [C II] 158 mu cooling rates, lc, we find a distribution with peaks at lc=10^-27.4 and 10^-26.6 ergs s^-1 H^-1 separated by a trough at lc^crit ~= lc < 10^-27.0 ergs s^-1…
We study the distribution of the star formation rate and metallicity of damped Lyman-alpha absorbers using cosmological SPH simulations of the Lambda cold dark matter model in the redshift range z=0-4.5. Our approach includes a…
We investigate some basic properties of Damped Lyman alpha systems based on the Semi-Analytical model of disk galaxy formation theory. We derive the DLA metallicity, column density, number density, gas content and cosmic star formation rate…
We present a study of the early build-up of dust in high redshift galaxies. The study is based on the analysis of 38 Damped Ly alpha systems (DLAs) for which we derive the fraction of iron atoms in dust form, f_{Fe}. The sample is…
We describe cosmological simulation techniques and their application to studies of cosmic structure formation, with particular attention to recent hydrodynamic simulations of structure in the high redshift universe. Collisionless N-body…
We probe the physical conditions in high redshift galaxies, specifically, the Damped Lyman-alpha Systems (DLAs) using neutral carbon (CI) fine structure lines and molecular hydrogen (H2). We report five new detections of CI and analyze the…