GCN Circular 8225
Subject
GRB 080913: VLT/FORS spectrum
Date
2008-09-13T17:28:26Z (16 years ago)
From
Jochen Greiner at MPI <jcg@mpe.mpg.de>
J.P.U. Fynbo (DARK/NBI), J. Greiner, T. Kruehler (both MPE),
A. Rossi (Tautenburg Obs), P. Vreeswijk, D. Malesani (both DARK/NBI)
report on behalf of a larger collaboration
Based on the rapid determination of an i'-band drop out we triggered
VLT/ToO observations (program-ID 081.A-0135; PI Greiner) and obtained
spectroscopy with FORS2+Gris600z of the afterglow of GRB080913
(Schady et al. 2008, GCN #8217; Stamatikos et al. 2008, GCN #8222).
Observations started at 8:30, about 100 min after the GRB, and continued
until morning twilight. We detect a red continuum that disappears
bluewards of a break around 9400 AA. Interpreting this break
as the onset of the Lyman-alpha forest we infer a redshift
of about z=6.7 consistent with the photometric redshift determined
by GROND (Greiner et al., GCN #8223).
We are very grateful for the excellent support by the Paranal
observatory staff, in particular Rachel Gilmour and Heidi Korhonen.
[GCN OPS NOTE(06nov08): Per author's request, "Heidi Schmidt" was
changed to "Hiedi Korhonen".]