[vsnet-grb-info 17460] GRB 160117B: VLT/X-shooter spectroscopy

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18886
SUBJECT: GRB 160117B: VLT/X-shooter spectroscopy 
DATE:    16/01/18 05:35:54 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte at iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), G. Pugliese (API/UvA), 
D. Xu (NAOC/CAS), D. Malesani (DARK/NBI) report on behalf of a 
larger collaboration:

We observed the afterglow of GRB 160117B (Sonbas et al., GCN 18875; 
Yurkov et al., GCN 18877; Kruehler et al., GCN 18878, Malesani et al. 
GCN 18884, Hentunen et al. GCN 18885) with ESO's Very Large 
Telescope UT2 equipped with X-shooter. The spectra cover the range 
between 3000 and 18000 AA. Observations consisted of 4x1200s 
exposures, starting at 03:26 UT (13.45 hr after the GRB onset).

The optical counterpart is clearly detected in our grz acquisition images.

A preliminary analysis of the spectrum shows a clear continuum with 
absorption features due to FeII, MgII, as well as emission features of [OII], 
[OIII] and H-beta at a common redshift of 0.870, which we propose as 
redshift of the GRB.

We acknowledge the excellent support provided by the Paranal staff.