GCN Circular 20061
Subject
GRB 161014A: VLT/X-shooter redshift confirmation
Date
2016-10-17T12:23:39Z (8 years ago)
From
Jonatan Selsing at DARK/NBI <jselsing@dark-cosmology.dk>
J. Selsing (DARK/NBI), K. E. Heintz (Univ. of Iceland and DARK/NBI), D. Malesani
(DARK/NBI and DTU Space), D. Xu (NAOC), A. de Ugarte Postigo (IAA-CSIC and
DARK/NBI), N. R. Tanvir (Univ. Leicester), K. Wiersema (Univ. Leicester) and
J. P. U. Fynbo (DARK/NBI) report on behalf of a larger collaboration:
We have observed the optical afterglow of GRB 161014A (Racusin et al., GCN
20035; Morita et al. GCN 20036; Guidorzi et al., GCN 20037; D'Avanzo et al., GCN
20040), with the cross-dispersed echelle spectrograph, X-shooter, mounted at
VLT/UT2. Observations started 11.6 hours after the BAT trigger and consist of 4
x 1200 s integration time in the three spectral arms of X-shooter, covering 3000
- 21000 AA.
The afterglow continuum is detected in all arms at high significance. A broad
absorption trough from Lyman alpha is visible at 4650 AA, along with a number of
absorption lines spread across the rest of the afterglow continuum, among which
we identity absorption features due to Mg II, Si II, C II, C IV, Al II, Al III,
Fe II, all at a consistent redshift of z = 2.823, confirming the redshift
reported by de Ugarte Postigo et al. (GCN 20043).
We acknowledge excellent support from the ESO observing staff in Paranal, in
particular Jonathan Smoker, Thomas Rivinius, Marcela Espinoza and Dimitri Gadotti