The Nearby Damped Lyman-α Absorber Sbs 1543+593: a Large H I Envelope in a Gas-rich Galaxy Group

We present a Very Large Array (VLA) H I 21cm map and optical observations of the region around one of the nearest damped Lyman-α absorber 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 Lyman-α absorber. We discuss the H I and optical properties of SBS 1543+593 and its newly identified neighbors. Both SBS 1543+593 and Dwarf 1 have baryonic components that are dominated by neutral gas – unusual for damped Lyman-α 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. Subject headings: galaxies: individual(SBS1543+593) — galaxies: individual(MCG+10-22-038) — galaxies: structure — radio lines: galaxies — galaxies: dwarf — quasars: absorption lines