[vsnet-grb-info 17834] GRB16 0410A: Keck-I/LRIS redshift

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19278
SUBJECT: GRB16 0410A: Keck-I/LRIS redshift
DATE:    16/04/10 20:53:26 GMT
FROM:    Yi Cao at Caltech  <ycao at astro.caltech.edu>

Yi Cao, S. R. Kulkarni, Lin Yan, Vikram Ravi, H. K. Vedantham, Mansi M.
Kasliwal (Caltech)

We obtained a spectrum of the optical afterglow of GRB 160410A with the Low
Resolution Imaging Spectrometer (LRIS) on the Keck-I telescope at Mauna
Kea, following the Swift UVOT localization (GCN 19271). Our spectroscopic
integration started 84.25 minutes after the Swift trigger at airmass 1.05
and one 600s spectrum was obtained covering 3100-10200 Angstrom.

Our spectrum reveals a blue continuum superposed by a strong and broad
absorption around centered around 3300 Angstrom as well as a number of weak
and narrow absorption features. Upon obtaining the data we  determined a
redshift of 1.72  based primarily on the broad damped Lyman alpha and
threshold detection of narrow Si II, O I, C IV and Mg II absorption lines.
Our redshift is consistent to that derived from the VLT/X-shooter spectra
(GCN 19274).