GCN Circular 20150
Subject
GRB 161108A: NOT redshift
Date
2016-11-08T15:00:18Z (7 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC and DARK/NBI), D. Malesani (DARK/NBI
and DTU Space), D.A. Perley (DARK/NBI), J.P.U. Fynbo (DARK/NBI),
K.E. Heintz (Univ. of Iceland and DARK/NBI), A. Somero (UTU), E. Gafton
(NOT, SU, OKC), S. Damsted (Univ. Helsinki), G. Erfanianfar (MPE),
A. Finoguenov (Univ. Helsinki), C. Gibson (Univ. Helsinki), F. Kiefer (MPE),
C. Kirkpatrick (Univ. Helsinki), M. Lumme (Univ. Helsinki), V. Oja (Univ.
Helsinki), J. Rantakyla (Univ. Helsinki), I. Salmenpera (Univ. Helsinki), and
M. Seppala (Univ. Helsinki), report on behalf of a larger collaboration:
Continuing with the observations of GRB 161108A (Beardmore et al.,
GCN 20145) reported by Malesani et al. (GCN 20146) we performed
spectroscopy of the afterglow (see also Butler et al. GCN 20149) and host
galaxy using the Nordic Optical Telescope (NOT) equipped with AlFOSC.
The observation consisted of 2x1200s+1x600s exposures using grism 4,
starting at 5:47 UT (2.25 hr after the burst).
The spectrum shows continuum from 3900 to 9300 AA, with a single
emission line at 8048 AA, consistent with being due to the [O II] doublet
at z=1.159. Additionally we detect low SNR absorption features consistent
with Mg II, Mg I, and Fe II at the same redshift, which we identify as the
redshift of the GRB.