A HIGH-METALLICITY HOST ENVIRONMENT FOR THE LONG-DURATION GRB 020819

Abstract

We present spectroscopic observations of the host galaxy and explosion site of long-duration gamma-ray burst GRB 020819. We determine a metallicity for this host environment of log(O/H) + 12 = 9.0 0.1, by far the highest metallicity determined for a long-duration gamma-ray burst (LGRB) to date. We compare the metallicity and other properties of the GRB 020819 host environment to existing observations of LGRB host galaxies and consider the implications that this metallicity has for our understanding of LGRB progenitor scenarios. We also consider how this unusually high metallicity may relate to the status of GRB 020819 as a "dark" burst, with no detected optical afterglow.