Keck Spectroscopy and Hubble Space Telescope Imaging of GRB 000926: Probing a Host Galaxy at z = 2.038

Abstract

We present early-time Keck spectroscopic observations and late-time Hubble Space Telescope (HST) imaging of GRB 000926. The HST images show a small offset between the optical transient and a bright, compact knot in the host galaxy. Combined with the large equivalent widths measured for metallic absorption lines by the Keck Echellette Spectrograph and Imager (ESI) and the Low Resolution Imaging Spectrometer, this indicates that the GRB exploded inside a region of high stellar density. The ESI spectroscopy reveals two absorption systems centered at z=2.0379+/-0.0008 with a velocity separation of 168 km s${}^{-}1$, which we interpret as being due to individual features in the host galaxy. The ratios of chromium to zinc equivalent widths indicate that the host is depleted in dust relative to local values to a similar degree as damped Lyα systems at the same redshift.