The Lyα Forest Toward 3C 273 and PKS 0405-123
Abstract
We present high resolution STIS echelle spectra of two low redshift QSOs, 3C 273 (z=0.158) and PKS 0405-123 (z=0.574), as part of a STIS Investigation Definition Team (IDT) key project to determine the redshift density, H I column density and Doppler parameter distributions of weak Lyα forest systems at low redshift. We estimate completeness limits for both lines of sight based on an analysis of simulated spectra. Our goal is to compare results with simulations of cosmological evolution, in order to make constraints on the physical characteristics of the intergalactic medium and UV background flux. We also find a variety of Galactic and intergalactic metal absorption lines, including O VI from intervening systems, which will be useful in studies of gas from the halo of the Galaxy and galaxies out to z ~ 0.6.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AAS...19916118W