[vsnet-grb-info 2978] GRB 060223: Keck redshift

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4815
SUBJECT: GRB 060223: Keck redshift
DATE:    06/02/23 08:19:49 GMT
FROM:    Edo Berger at Carnegie Obs  <eberger at ociw.edu>

E. Berger (Carnegie), S. R. Kulkarni, A. Rau (Caltech), and D. B. Fox
(Penn State) report on behalf of a large collaboration:

"Starting on 2006, Feb 23.2875 UT (39 min after the burst) we obtained
spectroscopic observations of the optical afterglow of GRB 060223 (GCNs
4813,4814) using LRIS on the Keck-I 10-m telescope.  In a single 720 sec
exposure we detect a broad absorption profile which we identify as
Lyman-alpha at a redshift z=4.41, as well as metal absorption features
from OI, SiII, SiII*, etc at the same redshift."