GCN Circular 13251
Subject
GRB 120422A: Gemini redshift of candidate host
Date
2012-04-22T20:18:05Z (12 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), A. Cucchiara (UCSC/UCO Lick) &
D. B. Fox (Penn State) report on behalf of a larger collaboration:
Further analysis of the Gemini/GMOS spectrum of the nearby galaxy reported by
Cucchiara et al. (GCN 13245) revealed emission lines of Ha, OIII(5007/4959) and Hb
at a common redshift of z=0.28. At this redshift, the impact parameter of the afterglow
is about 8kpc, which would be a rather large offset for a long-GRB, but certainly possible.
If the galaxy is the host, then the absence of absorption lines in the afterglow spectrum
would not be too surprising, given the weakness of expected lines in the observed
wavelength range. However, it would also make it one of the lowest
redshift GRBs so far detected by Swift, and so an important target for further follow-up.