GRB afterglow absorption line spectroscopy - Elemental abundances and physical conditions in the GRB host galaxy

We present absorption line spectroscopy of two gamma-ray bursts, GRB 051111, and GRB 060210, and demonstrate some of the diagnostics available within the absorption lines for determining the elemental composition, density and temperature of the GRB afterglow regions. We also present a scaled GRB model in which the afterglow region is considered as a portion within a much larger galaxy, and the astrophysical implications of the different possible geometries within the GRB host galaxy for interpreting the diagnostics derived from fine-structure absorption lines.