Related papers: Metallicity Evolution of Damped Lyman Alpha System…
Quasar absorption systems not only affect the way quasars are selected, but also serve as key probes of galaxies, providing insight into their chemical evolution and interstellar medium (ISM). Recently, a method based on Gaia astrometric…
Recent chemical abundance measurements of damped Ly-alpha absorbers (DLAs) revealed an intrinsic scatter in their metallicity of ~0.5 dex out to z~5. In order to explore the origin of this scatter, we build a semi-analytic model which…
Images of five QSO fields containing six damped Lyman alpha (DLA) systems at redshifts 0.09<z<0.53 are presented. Identifications for the DLA galaxies giving rise to the DLA systems are made. The observed and modeled characteristics of the…
We investigate the chemical abundances of local star-forming galaxies which cause Damped Lyman Alpha lines. A metallicity versus redshift diagram is constructed, on which the chemical abundances of low-redshift star-forming galaxy…
We report the identification of a very metal-poor damped Lyman-alpha system (DLA) at z_abs = 3.067295 that is modestly carbon-enhanced, with an iron abundance of ~1/700 solar ([Fe/H] = -2.84) and [C,O/Fe] ~ +0.6. Such an abundance pattern…
We test the hypothesis that the host galaxies of long-duration gamma-ray bursts (GRBs) as well as quasar-selected damped Lyman-alpha (DLA) systems are drawn from the population of UV-selected star-forming, high-z galaxies (generally…
We present a detailed high spectral resolution (R $\sim$ 40000) study of five high-z damped Lyman $\alpha$ systems (DLAs) and one sub-DLA detected along four QSO sightlines. Four of these DLAs are very metal-poor with [Fe/H] $\le$ $-$2. One…
We present the first results from a survey of SDSS quasars selected for strong H I damped Lyman-{\alpha} (DLA) absorption with corresponding low equivalent width absorption from strong low-ion transitions (e.g. C II {\lambda}1334 and Si II…
The chemical composition of the gas in galaxies versus cosmic time provides a very important tool for understanding galaxy evolution. Although there are many studies at high redshift, they are rather scarce at lower redshifts. However, low…
We study the evolution with redshift, from z=5 to z=0, of the Lyman-alpha forest in a CDM model using numerical simulations including collisionless particles only. The baryonic component is assumed to follow the dark matter distribution. We…
The Damped and sub-Damped Lyman-alpha (DLA and sub-DLA) systems seen in the spectra of QSOs offer a unique way to study the interstellar medium of high redshift galaxies. In this paper we report on new abundance determinations in a sample…
I review the observational characteristics of intermediate-to-high redshift star forming galaxies, including their star formation rates, dust extinctions, ISM kinematics, and chemical compositions. I present evidence that the mean rate of…
We report {\it HST} COS spectroscopy of 10 quasars with foreground star-forming galaxies at 0.02$<$$z$$<$ 0.14 within impact parameters of $\sim$1-7 kpc. We detect damped/sub-damped Ly$\alpha$ absorption in 100$\%$ of cases where no…
Using our sample of the most metal-rich damped Lyman $\alpha$ systems (DLAs) at z$\sim2$, and two literature compilations of chemical abundances in 341 DLAs and 2818 stars, we present an analysis of the chemical composition of DLAs in the…
Recent observations with the James Webb Space Telescope are yielding tantalizing hints of an early population of massive, bright galaxies at $z > 10$, with Atacama Large Millimeter Array (ALMA) observations indicating significant dust…
We investigate the properties of damped Lyman-alpha systems (DLAS) in semi-analytic models, focusing on whether the models can reproduce the kinematic properties of low-ionization metal lines described by Prochaska & Wolfe (1997b, 1998). We…
We analyze evolution of the basic properties of simulated large scale structure elements formed by dark matter (DM LSS) and confront it with the observed evolution of the Lyman-$\alpha$ forest. In three high resolution simulations we…
We present the elemental abundance and H2 content measurements of a Damped Lyman-{\alpha} (DLA) system with an extremely large H i column density, log N(H i) (cm-2) = 22.0+/-0.10, at zabs = 3.287 towards the QSO SDSS J 081634+144612. We…
Most galaxy evolution simulations as well as a variety of observational methods assume a linear scaling between the (galaxy-averaged) dust-to-gas ratio D and metallicity Z of the interstellar medium (ISM). Indeed, nearby galaxies with solar…
Our knowledge of galactic chemical evolution is currently limited to observations of Milky Way stars and H II regions of nearby galaxies. Damped Lyman~$\alpha$ systems offer a new approach for tracking the evolution of normal galaxies from…