GCN Circular 9797
Subject
GRB090814A: VLT spectroscopy
Date
2009-08-14T05:07:03Z (15 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
P. Jakobsson (Univ. Iceland), A. de Ugarte Postigo (INAF-OAB),
J. Gorosabel (IAA-CSIC), N. Tanvir (Leicester),
L. Christensen (ESO), J.P.U. Fynbo (DARK/NBI)
report on behalf of a larger collaboration,
We have observed the field of GRB 090814A (Ukwatta et al. GCN 9793)
using FORS2 at the VLT (Paranal observatory) starting at 02:05 UT
(70 minutes after the burst). We detect the object identified by
Updike et
al. (GCN 9794) with a magnitude of R~21.5.
The spectrum shows continuum down to at least 3900 Angstroms.
Non detection of Ly-alpha implies a limit of z < 2.2. We identify a
weak absorption system at z=0.696 through the detection of MgII and
CaII.
This is therefore likely to be the redshift of the GRB but we note that
it could also be produced by an intervening system and thus the strict
redshift range for this GRB would be 0.696 < z < 2.2.
We acknowledge the excelent support from Parnal observatory, in
particular J. Smoker and L. Rivas.