相关论文: The Origin of \lya Absorption Systems at $z>1$---I…
We present results of an ongoing program to study the gaseous extent of galaxies and the origin of QSO absorption line systems. For \lya absorption systems, we find that absorption equivalent width depends strongly on galaxy impact…
We present initial results of a program to obtain and analyze HST WFPC2 images of galaxies identified in an imaging and spectroscopic survey of faint galaxies in fields of HST spectroscopic target QSOs. We measure properties of 87 galaxies,…
In this work we shall sketch a further piece of evidence for the plausibility of hypothesis of galactic origin of Ly-$\alpha$ forest absorption systems. Two basic premises of our discussion are (1) HDF redshift surface densities in the…
We present initial results of a program to obtain and analyze HST WFPC2 images of galaxies in fields of HST spectroscopic target QSOs. The goal of the program is to investigate how the properties of \lya absorption systems observed in the…
We present evidence that clumps of \lya lines are physically associated with about half of the extensive metal-line systems (absorption systems with four or more observed metal-line species) found in this paper, demonstrate that all four…
We present initial results of an imaging and spectroscopic survey of faint galaxies in fields of Hubble Space Telescope spectroscopic target QSOs. The primary objectives of the survey are (a) to determine the incidence, extent, and covering…
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…
A scenario is explored in which Lyman alpha absorbers at low redshift arise from lines of sight through extended galaxy disks, including those of dwarf and low surface brightness galaxies. A population of galaxies is simulated based upon…
I review current results from searching for galaxies giving rise to damped Lya absorbers (DLAs) at z<1. Using 14 confirmed DLA galaxies, I further show that intermediate-redshift galaxies possess large HI envelope out to 24-30 h^{-1} kpc…
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,…
(Abridged) We present results of a program to obtain and analyze HST WFPC2 images and ground-based images of galaxies identified in an imaging and spectroscopic survey of faint galaxies in fields of HST spectroscopic target QSOs. We confirm…
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…
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…
We use a model of galaxy disk formation to explore the metallicities, dust content, and neutral-gas mass density of damped Lyman-$\alpha$ (D\lya) absorbers. We find that the [Zn/H] abundance measurements of D\lya systems now available can…
Using simulations of the low redshift galaxy population based upon galaxy observations, it is shown (Linder 1998) that the majority of Ly$\alpha$ absorbers at low redshift could arise in low surface brightness (LSB) galaxies. The…
The Lyman decrement associated with the cumulative effect of HI in QSO absorption systems along the line of sight provides a distinctive feature for identifying galaxies at z>2.5. The Hubble Deep Field (HDF) observations offer the…
We investigate the properties of the HI Ly-a absorption systems (Ly-a forest) within and around galaxy voids at z<0.1. We find a significant excess (>99% c.l.) of Ly-a systems at the edges of galaxy voids with respect to a random…
We study the nature of damped Lya absorption (DLA) systems at z<=1 using a sample of 11 DLA galaxies, for which accurate redshift measurements are available. We demonstrate that the precision of photometric redshifts is sufficient for…
I review some recent progress made in our understanding of galaxy evolution and the cosmic history of star formation. The Hubble Deep Field (HDF) imaging survey has achieved the sensitivity to capture the bulk of the extragalactic…
Essentially all high-redshift galaxies show evidence for strong large-scale outflows that should have a profound effect on the structure and kinematics of both the galaxies themselves and their environment. The interstellar absorption…