GRB 010921: Discovery of the First High Energy Transient Explorer Afterglow

Price, Paul; Kulkarni, Shrinivas R; Berger, Edo; Djorgovski, S G; Frail, Dale A; Mahabal, A; Fox, Derek B; Harrison, F A; Bloom, J S; Yost, S A; Reichart, D E; Henden, A A; Ricker, G R; Van Der Spek, R; Hurley, K C; Atteia, J.-L.; Kawai, N; Fenimore, F; Graziani, C

GRB 010921: Discovery of the First High Energy Transient Explorer Afterglow

Date

2002

Authors

Price, Paul

Kulkarni, Shrinivas R

Berger, Edo

Djorgovski, S G

Frail, Dale A

Mahabal, A

Fox, Derek B

Harrison, F A

Bloom, J S

Yost, S A

Publisher

IOP Publishing

Abstract

We report the discovery of the optical and radio afterglow of GRB 010921, the first gamma-ray burst afterglow to be found from a localization by the High Energy Transient Explorer satellite. We present optical spectroscopy of the host galaxy, which we find to be a dusty and apparently normal star-forming galaxy at z = 0.451. The unusually steep optical spectral slope of the afterglow can be explained by heavy extinction, Av > 0.5 mag, along the line of sight to the GRB. Dust with similar Av for the host galaxy as a whole appears to be required by the measurement of a Balmer decrement in the spectrum of the host galaxy.