GCN Circular 16217
Subject
GRB 140506A: VLT/X-shooter spectroscopy
Date
2014-05-07T10:06:33Z (11 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
J. P. U. Fynbo (DARK/NBI), N. R. Tanvir (U. Leicester), P. Jakobsson
(U. Iceland), D. Xu, D. Malesani, B. Milvang-Jensen (DARK/NBI) report
on behalf of the X-shooter GRB collaboration:
We observed the optical afterglow of GRB 140506A (Gompertz et al., GCN
16214) with the VLT/X-shooter spectrograph, equipped with the
UVB/VIS/NIR arms and covering the wavelength range 3000-25000 AA.
From the first acquisition image at May 7.21 UT, the afterglow has
m(R)=20.9 +/- 0.2 mag against the USNO-B1 (R2) catalog.
The spectra (8 x 600 s) started at May 7.21 UT and ended May 7.28 UT,
and the mean time is May 7.24 UT (8.77 hr after the GRB). We detect
absorption features in the UVB/VIS arms, interpreted as due to Mg II
2796, 2803, He I 3889, and Ca II H+K, at a common redshift of z =
0.889, which is treated as the tentative redshift of the GRB's host
galaxy. The combined spectrum is very red with very weak signal in the
UVB arm, possibly due to the large host extinction.
We acknowledge excellent support from the observing staff at Paranal,
in particular Valentin D. Ivanov and Yazan Momany.