[vsnet-grb-info 5798] VLT/UVES redshift of GRB 080319B from FeII fine-structure lines

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7451
SUBJECT: VLT/UVES redshift of GRB 080319B from FeII fine-structure lines
DATE:    08/03/19 16:36:37 GMT
FROM:    Paul Vreeswijk at Dark Cosmology Centre,U.of Copenhagen  <pmv at dark-cosmology.dk>

P.M. Vreeswijk, Bo Milvang-Jensen (DARK), A. Smette (ESO),
D. Malesani, J.P.U. Fynbo (DARK), P. Jakobsson (U. Hertfordshire),
A.O. Jaunsen (U. Oslo) and C. Ledoux (ESO) report on behalf of a
larger collaboration:

Besides the absorption systems at z=0.937 and z=0.530 reported in GCN
7444, we also note the presence of two other systems at z=0.715 and
z=0.760 along the sightline toward GRB 080319B. The rest-frame
equivalent width of MgII 2796 for both the z=0.937 and z=0.715 systems
is large: greater than 1A.  Finally, we detect several transitions
from FeII fine-structure levels from the z=0.937 system. Assuming that
the GRB afterglow is responsible for the FeII excitation (see
Prochaska et al. 2006, ApJ, 648, 95; Vreeswijk et al. 2007, A&A, 468,
83), this confirms the z=0.937 system to be the host of GRB 080319B.