Early X-ray/UV Line Signatures of GRB Progenitors and Hypernovae

We calculate the X-ray/UV spectral line signatures expected from the interaction of a gamma-ray burst afterglow and a dense pre-burst environment produced by the progenitor. We calculate the conditions under which Fe line and edge equivalent widths of $\sim$ 1 keV can arise, and discuss the possibility of gaining information about possible progenitor scenarios using X-ray metal line spectra in the first few days of a burst. A wind or supernova remnant around the burst could produce an X-ray emission line spectrum, as well as X-ray absorption, while a hypernova funnel model would produce mainly emission lines. A detectable solar composition wind would require more mass and would produce stronger 0.5-2 keV absorption lines than an Fe-enriched supernova remnant. The bound-free Fe edge equivalent widths are predicted to peak later and may be easier to detect than the Fe K-$\alpha$ line in shell models, while the opposite holds for hypernova models.