TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1340
SUBJECT: GRB 020405: Moderate-resolution spectroscopy
DATE:    02/04/08 19:25:15 GMT
FROM:    Paul Price at RSAA, ANU at CIT  <pap@srl.caltech.edu>

P.A. Price (Caltech), M. Pettini (Cambridge), N. Reddy, C. Steidel
and S.R. Kulkarni (Caltech) report on behalf of the REACT GRB
collaboration:

We have observed the afterglow of GRB 020405 (GCN #1326) with the
Keck II telescope + ESI.  Observations consisted of 2x1800 sec exposures
in the eschellete mode.  In this mode we are able to resolve the sky
lines, which is particularly important since at the reported redshift
of z = 0.695 (Masetti et al., GCN #1330) the [O II] line is coincident
with a strong atmospheric line.  A preliminary reduction of the spectra
reveals emission lines of [O II], Hbeta, and [O III], at a mean redshift
of z = 0.6898 +/- 0.0005.  In particular, we resolve the [O II] doublet
and thus we consider the redshift to be secure.

This message may be cited.