Related papers: The Connections between QSO Absorption Systems and…
Quasar absorption lines provide detailed information on the chemical, kinematic, and ionization conditions in galaxies and their environments, and provide a means for studying the evolution of these conditions back to the epoch of the first…
We examine the relationship between galaxies and the intergalactic medium at z < 1 using a group of three closely spaced background QSOs with z_em ~1 observed with the Hubble Space Telescope. Using a new grouping algorithm, we identify…
The importance of HST for the study of quasar absorption lines and of the nature of the intergalactic medium is illustrated by reviewing selected results from past HST observations. Topics reviewed include the study of Ly-alpha absorbers at…
We present results of surveys for high redshift galaxies selected by their having produced detectable Mg~II and Lyman limit absorption in the spectra of background QSOs. We discuss the properties of the absorbing galaxies, the connection…
High resolution rest frame UV quasar absorption spectra covering low and high ionization species, as well as the Lyman series lines, provide remarkably detailed information about the gaseous phases of galaxies and their environments. For…
The nature of the galaxies that give rise to absorption lines, such as damped Lyman-alpha systems (DLAs) or strong MgII lines, in quasar spectra is difficult to investigate in emission. Taking advantage of the total absorption of the QSO…
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…
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…
Absorption signatures in the spectra of QSOs are one of our most powerful tools for studying galactic and intergalactic environments at high redshifts. With the discovery of QSOs out to z > 7, QSO absorption lines are now tracing the end…
We detail a powerful indirect method for the study of damped Lyman alpha systems (DLAs) at low redshift. We increase the probability of finding a low-redshift DLA to nearly 50% by targeting QSOs that are known to have strong low-redshift…
The effects of galaxy selection on our ability to constrain the nature of weak Ly\alpha absorbers at low redshift are explored. Current observations indicate the existence of a population of gas-rich, low surface brightness (LSB) galaxies,…
We present a sample of 46 [OIII]-emitting galaxies at z<0.8 detected in the fibre spectra of quasars from the SDSS-DR7 through an automatic search procedure. We also detect [OII] and Hb emission lines from most of these galaxies in the SDSS…
We have obtained very deep near-infrared images in the fields of 10 QSOs whose spectra contain damped Lyman-alpha absorption (DLA) systems with 1.7<z_abs <2.5. The main aim of our investigation is to provide new constraints on the…
High-resolution UV spectroscopy of low-z QSOs with the Space Telescope Imaging Spectrograph and the Far Ultraviolet Spectroscopic Explorer has indicated that O VI absorption-line systems provide a valuable probe of the low-z intergalactic…
We review the ongoing debate about the relationship between low redshift Lyman Alpha absorbers and luminous galaxies. In particular, we discuss the difficulty of `assigning' a particular absorber to a particular galaxy, and consider methods…
We investigate the relative distribution of the gaseous contents of the Universe (as traced by a sample of Lyman alpha (lya) absorbers), and the luminous baryonic matter (as traced by a redshift survey of galaxies in the same volume…
Using a sample of nearly 700 quasars with strong (W_0(2796)>0.8 Angstrom) MgII absorption lines detected in the Early Data Release of the SDSS, we demonstrate the feasibility of measuring the photometric properties of the absorber systems…
We present results from a search for galaxies that give rise to damped Lyman alpha (DLA), subDLA, and Lyman limit system (LLS) absorption at redshifts 0.1 ~< z ~< 1 in the spectra of background quasars. The sample was formed from a larger…
We present the results of a search for metal absorption lines in the spectra of background QSOs whose sightlines pass close to foreground QSOs. We detect MgII(2796,2803) absorption in Sloan Digital Sky Survey (SDSS) spectra of four z>1.5…
This white paper emphasizes the potential of QSO absorption lines in the rest-frame far/extreme UV at rest-frame wavelengths from ~500 to 2000 A. In this wavelength range, species such as Ne VIII, Na IX, and Mg X can be detected, providing…