Damped Lyα absorption from a nearby low surface brightness galaxy

Ground-based and Hubble Space Telescope (HST) images of the nearby galaxy SBS 1543+593 (z = 0.009) show it to be a low surface brightness (LSB) galaxy with a central surface brightness mu (B)(0) = 23.2 mag arcsec(-2) and scale length 0.9 h(100)(-1) kpc, values typical for the local LSB galaxy population. The galaxy lies directly in front of the quasi-stellar object HS 1543+5921 (z = 0.807); an HST STIS spectrum of the quasar reveals a damped Ly alpha (DLy alpha) line at the redshift of the interloper with an H I column density of log N(H I) = 20.35, as well as several low-ionization metal lines with strengths similar to those found in the Milky Way interstellar medium. Our data show that LSB galaxies are certainly able to produce the DLy alpha lines seen at higher redshift and fuels the speculation that LSB galaxies are a major contributor to that population of absorbers.