[vsnet-grb-info 3734] GRB 060912: Redshift of nearby 2MASS galaxy

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5568
SUBJECT: GRB 060912: Redshift of nearby 2MASS galaxy
DATE:    06/09/13 06:56:08 GMT
FROM:    Edo Berger at Carnegie Obs  <eberger at ociw.edu>

E. Berger (Carnegie Observatories) reports on behalf of a larger 
collaboration:

"Starting on 2006 Sep. 13.22 UT we used GMOS on Gemini-South to obtain an 
1800 sec spectrum of the bright 2MASS galaxy located 11" away from the 
optical afterglow position of GRB 060912 (GCN 5558), at a position angle 
that also included the afterglow position.  The spectrum of the 2MASS 
galaxy it typical of an early-type galaxy with CaII H&K, Mg b, and Na D 
absorption features at a redshift, z=0.0936.  At the position of the 
afterglow we do not detect any clear continuum emission or emission lines 
(4000-7000 A).  If the 2MASS galaxy is in fact the host galaxy of GRB 
060912, then the isotropic-equivalent gamma-ray energy is only 2.6e49 erg. 
Moreover, the nature of the host galaxy would suggest that the GRB is most 
likely to be a short burst.  Deep imaging observations to search for a 
faint galaxy at the position of the afterglow are planned."