[vsnet-grb-info 4757] GRB 070611: VLT redshift

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6499
SUBJECT: GRB 070611: VLT redshift
DATE:    07/06/11 13:34:01 GMT
FROM:    Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr  <cthoene at astro.ku.dk>

Christina C. Thoene (DARK), Pall Jakobsson (Univ. of Hertfordshire), Johan
P. U. Fynbo, Daniele Malesani, Jens Hjorth (DARK) and Paul M. Vreeswijk
(ESO) report:

We observed the OT (Rykoff et al., GCN 6497) of GRB 070611 (Stroh et al.,
GCN 6494) with FORS2/VLT using grism 300V through thin clouds. 2x30 min
spectra were acquired starting on June 11, UT 09:37.

In the spectra, we detect Lyman alpha, SiII, OI, CII, CIV and AlII from
which we infer a redshift of z=2.04 for that burst. In addition, we detect Mg II
and Fe II from an intervening system at z=1.29.

We thank the Paranal staff for excellent support, in particular Arjan Bik
and Mario van den Ancker.