Related papers: The relation between QSO absorption systems and hi…
Recent observations have successfully detected [O III] $88.3\,{\rm \mu m}$ and [C II] $157.6\,{\rm \mu m}$ lines from galaxies in the early Universe with the Atacama Large Millimeter Array (ALMA). Combining cosmological hydrodynamic…
We develop a new method to determine the distance between a high-redshift galaxy and a foreground screen of atomic hydrogen. In a partially neutral universe, and assuming spherical symmetry, this equates to the radius of a ionized 'bubble'…
The absorption lines observed in quasar spectra have given us a detailed picture of the intergalactic medium and the metal abundance and kinematics of high redshift galaxies. In this review, we present an introduction to the field, starting…
Based upon QSO absorption line studies, galaxies at 0.3 < z < 1.0 are seen to have extended gaseous "halos". When the absorption lines are observed at high resolution, the velocity distribution of the absorbing gas gives clues as to where…
We incorporate quasars into an analytic model to describe the reheating and reionization of the universe. In combination with a previous study of galaxies and Lyman-$\alpha$ clouds, we are able to provide a unified description of structure…
We compare the properties of a sample of local (z=0) gas-rich galaxies studied in 21 cm emission to a sample of 13 low-redshift (z < 1) damped Lyman alpha (DLA) galaxies identified as the counterparts of low-redshift DLA systems found in…
We present predictions drawn from cosmological hydrodynamic simulations for the physical, photometric and emission line properties of galaxies present during the latter stages of reionization from z=9-6. We find significant numbers of…
To study the nature of low z Lya absorbers in the spectra of QSOs, we have obtained high signal-to-noise UV spectra of H 1821+643 (z = 0.297) and PG 1116+215 (z = 0.177) with the GHRS on the HST. The spectra have minimum S/N of 70-100 and 3…
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…
We present a detailed study of a rich galaxy cluster at z=2.38. We demonstrate that this cluster contains large overdensities of damped Ly-alpha absorption lines, of Ly-alpha emitting galaxies and of extremely red objects. The overdensity…
Context. Absorbing galaxies are selected via the detection of characteristic absorption lines which their gas-rich media imprint in the spectra of distant light-beacons. The proximity of the typically faint foreground absorbing galaxies to…
We estimate the evolution of the contribution of galaxies to the cosmic background flux at $912 \AA$ by means of a semi-analytic model of galaxy formation and evolution. Such a modelling has been quite successful in reproducing the optical…
We present spectra of QSOs 1343+266 A B, covering Ly-beta to C~IV emission at 2\AA~resolution, and find further evidence that this system is not gravitationally lensed. We see, however, a large number of Ly-alpha and some C~IV absorption…
We report the serendipitous detection of a 0.2 L$^*$, Lyman-$\alpha$ emitting galaxy at redshift 2.5 at an impact parameter of 50 kpc from a bright background QSO sightline. A high-resolution spectrum of the QSO reveals a partial…
This study focuses on some of the most metal-poor damped Lyman alpha absorbers known in the spectra of high redshift QSOs, using new and archival observations obtained with UV-sensitive echelle spectrographs on the Keck and VLT telescopes.…
We examine the highest S/N spectra from the 2QZ 10k release and identify over 100 new low-ionisation heavy element absorbers; DLA candidates suitable for higher resolution follow-up observations. These absorption systems map the spatial…
The Lyman alpha (lya) line of Hydrogen is a prominent feature in the spectra of star-forming galaxies, usually redshifted by a few hundreds of km/s compared to the systemic redshift. This large offset hampers follow-up surveys, galaxy pair…
We present a survey for metal absorption systems traced by neutral oxygen over $3.2 < z < 6.5$. Our survey uses Keck/ESI and VLT/X-Shooter spectra of 199 QSOs with redshifts up to 6.6. In total we detect 74 O I absorbers, of which 57 are…
Evidence is presented that the damped Lyman alpha absorption systems are the high-redshift (z > 3) progenitors of galaxy disks. I discuss kinematic evidence that the damped Lyman Alpha systems are rotating disks. I also discuss implications…
We study the evolution with redshift of the number density of Ly$\alpha$ clouds in a CDM model using numerical simulations including photo-ionization and cooling of the baryonic component. The photo-ionizing flux is consistently taken as…