HI Column Density Distribution Function at z = 0: Connection to Damped Lyα Statistics

Density Distribution Fun tion at z = 0 : the Conne tion to Damped Ly Statisti sMartin

Density Distribution Function at z = 0 from H

We have measured the column density distribution function, f(NHI), at z = 0 using 21-cm Hi emission from galaxies selected from a blind Hi survey. f(NHI) is found to be smaller and flatter at z = 0 than indicated by high-redshift measurements of Damped Lyman-α (DLA) systems, consistent with the predictions of hierarchical galaxy formation. The derived DLA number density per unit redshift, dNDLA...

The NATURE OF DAMPED Lyα ABSORBING GALAXIES AT z ≤ 1–A PHOTOMETRIC REDSHIFT SURVEY OF DAMPED Lyα ABSORBERS

We study the nature of damped Lyα absorption (DLA) systems at z ≤ 1 using a sample of 11 DLA galaxies, for which accurate redshift measurements are available. Five of the 11 systems are identified in our on-going photometric redshift survey of DLA galaxies, while the remaining six systems are identified by previous groups using either spectroscopic or photometric redshift techniques. Absolute B...

Hi 21cm Absorption in Two Low Redshift Damped Lyα Systems

We report the discovery of two low redshift HI 21cm absorbers, one at z = 0.2212 towards the z em = 0.630 quasar OI 363 (B0738+313), and the other at z = 0.3127 towards PKS B1127-145 (z em = 1.187). Both were found during a survey of MgII selected systems at redshifts 0.2 < z < 1 using the new UHF-high system at the Westerbork Synthesis Radio Telescope (WSRT). New HST/FOS observations also iden...

GMRT Observations of Low z Damped Lyα Absorbers

We present Giant Metrewave Radio Telescope (GMRT) observations of redshifted HI 21cm absorption in two low redshift (z = 0.2212, z = 0.0912) damped Lyα systems seen towards the Gigahertz peaked source OI 363 (zem = 0.630). The object at z = 0.0912 is the lowest redshift damped Lyα system known to date. Ground based imaging (Rao & Turnshek 1998) shows that at neither redshift is there a large sp...