Related papers: Probing High-Redshift Disks with Damped Lyman Alph…
In this work, observational evidence for the connection between low column density Lyman-alpha absorbers and large-scale structure traced by gas-rich galaxies is investigated. The HI Parkes All Sky Survey (HIPASS) galaxy catalogue is…
We present a study of HI-rich galaxies in the local universe selected from blind emission-line surveys. These galaxies represent the emission-line counterparts of local damped Lyman-alpha systems. We find that the HI cross-section of…
We study the contents of an apparent void in the distribution of Ly-alpha emitting galaxies at redshift 2.38. We show that this void is not empty, but contains a damped Ly-alpha absorption-line system, seen in absorption against background…
Absorbers seen in the spectrum of background quasars are a unique tool to select HI-rich galaxies at all redshifts. In turns, these allow to determine the cosmological evolution of the HI gas, Omega_HI+HeII, a possible indicator of gas…
We present deep GMRT 21cm absorption spectra of 10 damped Lyman-$\alpha$ systems (DLAs), of which 8 are at redshifts $z \ga 1.3$. HI absorption was detected in only one DLA, the $z = 0.5318$ absorber toward PKS 1629+12, which has been…
I review measurements of element abundances in different components of the high redshift universe, including the Lyman alpha forest, damped Lyman alpha systems, and Lyman break galaxies. Although progress is being made in all three areas,…
We image 19 quasars with 22 damped Lyman alpha (DLA) systems using the F160W filter and the Near-Infrared Camera and Multiobject Spectrograph aboard the Hubble Space Telescope, in both direct and coronagraphic modes. We reach 5 sigma…
We report the discovery of two damped Ly-alpha absorption-line systems (DLAs) near redshift z=1 along a single quasar sightline (Q1727+5302) with neutral hydrogen column densities of N(HI) = (1.45\pm0.15)\times10^{21} and…
We present the two-point cross-correlation function between Lyman $\alpha$ absorbers and HI galaxies in the nearby Universe ($0.01 \le z \le 0.057$). We use absorbers from 21 QSO sightlines from the Survey of the Low-Redshift Intergalactic…
We report the detection of the host galaxy of a damped Ly$\alpha$ system (DLA) with log N(HI) $ [\rm cm^{-2}]$ = $21.0 \pm 0.10$ at $z \approx 3.0091$ towards the background quasar SDSS J011852+040644 using the Palomar Cosmic Web Imager…
We investigate chemical enrichment in Damped Lyman alpha (DLA) systems in the hierarchical structure formation scenario using a semi-analytic model of galaxy formation. The model developed by Nagashima, Totani, Gouda and Yoshii takes into…
We present models for dusty high-redshift Lyman alpha emitting galaxies by combining the Press-Schechter formalism with a treatment of inhomogeneous dust distribution inside galaxies. These models reproduce the surface density of emitters…
The chemical abundances in damped Lyman-alpha systems (DLAs) show more than 2 orders of magnitude variation at a given epoch, possibly because DLAs arise in a wide variety of host galaxies. This could significantly bias estimates of…
Lyman alpha emission presents a means of identifying very high redshift galaxies, provided such objects can be reliably distinguished from foreground emission-line galaxies. Here we report on a program of imaging and spectroscopic studies…
In this paper we present Monte-Carlo simulations of Lyman alpha absorption systems which originate in galactic haloes, galaxy discs and dark matter (DM) satellites around big central haloes. It is found that for strong Lyman alpha…
We investigate the Lyman alpha line transfer in nearby and high redshift starbursting galaxies, where the effect of high optical depths and the role of dust in the scattering medium are expected to be conspicuous and should be treated in a…
We demonstrate that the Lyman alpha emission in the absorption troughs of a large sample of stacked damped Lyman alpha absorption systems (DLAS) presented by Rahmani et al (2010) is consistent with the spectral profiles and luminosities of…
We have examined some basic properties of damped Ly$\alpha$ systems(DLAs) by semi-analytic model. We assume that DLA hosts are disk galaxies whose mass function is generated by Press-Schechter formulism at redshift 3. Star formation and…
An accurate method to measure the abundance of high-redshift galaxies consists in the observation of absorbers along the line of sight toward a background quasar. Here, we present abundance measurements of 13 z>3 sub-Damped Lyman-alpha…
We present arguments based on the measured abundances in individual damped Lyman alpha systems (DLAs) and sub-damped Lyman alpha systems (sub-DLAs), and also the average abundances inferred in large samples of QSO absorption line systems,…