TITLE:   GCN CIRCULAR
NUMBER:  23632
SUBJECT: GRB 190106A: VLT/X-shooter redshift confirmation
DATE:    19/01/07 13:01:48 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

P. Schady (Univ. of Bath), D. Xu (NAOC), K. E. Heintz (Univ. of Iceland), N. R. Tanvir (Univ. Leicester), D. B. Malesani (DAWN/NBI and DARK/NBI), D. A. Kann (HETH/IAA-CSIC), R. Sanchez-Ramirez (INAF/IAPS) and K. Wiersema (Univ. of Warwick) report:

We observed the optical counterpart of GRB 190106A (Sonbas et al., GCN #23615; Yurkov et al., GCN #23614) with the ESO-VLT UT2 (Kueyen) equipped with the X-shooter spectrograph, covering the wavelength range 3000-21000 AA. We acquired four 600 second spectra on 2019-01-07 between 00:53UT and 01:47UT, approximately 11 hours after the GRB. In the acquisition image we measure r = 19.47 +/- 0.02 (AB), calibrated against a nearby Pan-STARRS object.

We detect several absorption features at a common redshift z = 1.859, consistent with the value reported by Xu et al. (GCN #23629) and Mao et al. (GCN #23630). In addition to the absorption lines reported by Xu et al. and Mao et al., we also detect O I, C II, Mg I, and C IV, all at the same redshift, as well a broad feature due to H I Lyalpha absorption.

We acknowledge Steffen Mieske and Joe Anderson at Paranal for their excellent help in obtaining these observations.