[vsnet-grb-info 7977] GRB 090618: Lick/KAST Spectroscopy

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9518
SUBJECT: GRB 090618: Lick/KAST Spectroscopy
DATE:    09/06/18 12:37:12 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko at srl.caltech.edu>

S. B. Cenko, D. A. Perley (UC Berkeley), V. Junkkarinen, M. Burbidge (UC
San Diego), and K. Miller (UCO Lick Observatory) report on behalf of a
larger collaboration:

We have obtained a spectrum of the afterglow (GCNs 9512, 9513, 9514, 9515)
of GRB 090618 with the KAST spectrograph on the 3-m Shane telescope at
Lick Observatory.  Observations began at 08:48 UT on 18 June 2009,
approximately 20 minutes after the burst.  On the blue channel (using the
830/3460 grism, providing wavelength coverage from 3200 - 4400 A), we
detect a number of strong absorption features that we identify as Mg II,
Mg I, and Fe II at a common redshift of z = 0.54.  We believe this likely
to be the redshift of the GRB, as the lack of Lyman-alpha absorption
limits the GRB host to lie at z <~ 1.6.

Further analysis is in progress.