The Nearby Damped Lyα Absorber SBS 1543+593: A Large H I Envelope in a Gas-rich Galaxy Group
Abstract
We present a Very Large Array H I 21 cm map and optical observations of the region around one of the nearest damped Lyα absorbers beyond the Local Group, SBS 1543+593. Two previously uncataloged galaxies have been discovered, and a redshift has been determined for a third. All three of these galaxies are at the redshift of SBS 1543+593 and are <~185 kpc from the damped Lyα absorber. We discuss the H I and optical properties of SBS 1543+593 and its newly identified neighbors. Both SBS 1543+593 and RBTB 154542.8+591132 have baryonic components that are dominated by neutral gas-unusual for damped Lyα absorbers, for which only ~5% of the H I cross section originates in such strongly gas-dominated systems. What remains unknown is whether low-mass gas-rich groups are common surrounding gas-rich galaxies in the local universe and whether the low star formation rate in these systems is indicative of a young system or a stable, slowly evolving system. We discuss these evolutionary scenarios and future prospects for answering these questions.
- Publication:
-
The Astronomical Journal
- Pub Date:
- August 2006
- DOI:
- 10.1086/505047
- arXiv:
- arXiv:astro-ph/0604220
- Bibcode:
- 2006AJ....132..478R
- Keywords:
-
- Galaxies: Dwarf;
- Galaxies: Individual: Alphanumeric: SBS 1543+593;
- galaxies: individual (MCG +10-22-038);
- Galaxies: Structure;
- Galaxies: Quasars: Absorption Lines;
- Radio Lines: Galaxies;
- Astrophysics
- E-Print:
- 11 pages, AJ accepted