Showing papers by "Jane R. Rigby published in 1999"
TL;DR: In this article, a search for weak Mg II absorbers was conducted and the number density of the absorbers with Wr(2796) ≥ 0.02 A was found to be primarily due to a high-metallicity selection effect.
Abstract: We present a search for weak Mg II absorbers [those with Wr(2796) (2796)=0.02 A and that this is primarily a high-metallicity selection effect ([Z/Z☉] ≥ -1). This implies that Mg II absorbing structures figure prominently as tracers of sub-LLS environments where gas has been processed by stars. We compare the number density of Wr(2796) ≥ 0.02 A absorbers with that of both high and low surface brightness galaxies and find a fiducial absorber size of 35 h-1-63 h-1 kpc, depending upon the assumed galaxy population and their absorption properties. The individual absorbing clouds have Wr(2796) ≤ 0.15 A, and their narrow (often unresolved) line widths imply temperatures of ~25,000 K. We measured Wr(1548) from C IV in Faint Object Spectrograph/Hubble Space Telescope archival spectra and, based upon comparisons with Fe II, found a range of ionization conditions (low, high, and multiphase) in absorbers selected by weak Mg II.
176 citations