GCN Circular 3390
Subject
Keck/DEIMOS Spectrum of Possible Host Galaxy for GRB050509b
Date
2005-05-09T09:22:11Z (20 years ago)
From
Josh Bloom at Harvard/CFA <jbloom@cfa.harvard.edu>
J. X. Prochaska (UCO/Lick), M. Cooper (UCB), J. Newman (LBNL),
J. S. Bloom (UCB), K. Hurley, (SSL/UCB), C. Blake (Harvard),
B. Gerke (UCB), and H. W. Chen (MIT) report:
"We have acquired a DEIMOS longslit spectrum of the galaxy at ra
12:36:12.90, dec +28:58:58.8 (J2000) (=2MASS 2MASX J12361286+2858580)
which is tentatively identified as the host of GRB 050509b. We measure a
redshift of z=0.226 based on Ca H and K absorption and numerous other
absorption features. We do not detect any significant emission at Hbeta,
Halpha or [O II]. The spectral features are consistent with an early
type galaxy with no ongoing star formation. If the association is
confirmed, this would be the first GRB host that is an early-type, hinting
that GRBs of short duration may be due to progenitors that are unrelated
to current and on-going star formation.
This notice may be cited."