The contribution of H I-rich galaxies to the damped Lyα absorber population at z = 0.
ROSENBERG J.L. and SCHNEIDER S.E.
Abstract (from CDS):
We present a study of the expected properties of the low-redshift damped Lyα absorber population determined from a sample of H I-selected galaxies in the local universe. Because of a tight correlation between the H I mass and H I cross section, which we demonstrate spans all galaxy types, we can use our H I-selected sample to predict the properties of the absorption-line systems. We use measurements of the number density and H I cross section of galaxies to show that the total H I cross section at column densities sufficient to produce damped Lyα absorption is consistent with no evolution of the absorber population. We also find that the dN/dz distribution is dominated by galaxies with H I masses near 109 M☉. However, because of the large dispersion in the correlation between H I mass and stellar luminosity, we find that the distribution of dN/dz as a function of LJis fairly flat. In addition, we examine the line widths of the H I-selected galaxies and show that there may be evolution in the kinematics of H I-rich galaxies, but it is not necessary for the higher redshift population to contain a greater proportion of high-mass galaxies than we find locally.
Galaxies: ISM - Galaxies: Quasars: Absorption Lines - Radio Lines: Galaxies