[vsnet-grb-info 19139] GRB 170214A: VLT/X-shooter spectroscopy and tentative redshift

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20686
SUBJECT: GRB 170214A: VLT/X-shooter spectroscopy and tentative redshift
DATE:    17/02/16 16:41:59 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler at mpe.mpg.de>

T. Kruehler, P. Schady, J. Greiner (all MPE Garching) and
N. R. Tanvir (U. Leicester) report:

We observed the optical counterpart (Troja et al. GCN 20681,
Malesani et al. GCN 20683, Schady et al. GCN 20684) of GRB 170214A
(Mailyan and Meegan, GCN 20675, Racusin et al. GCN 20676)
with the ESO Very Large Telescope UT 2 (Kueyen) equipped
with the X-shooter spectrograph, covering the wavelength range
3200-20000 AA. Observations started at 08:18 UT on 2017-02-16,
roughly 40.7 hours after the burst and consisted of 6 exposures
of 600 s each.

Our spectrum has a low signal-to-noise ratio with no signal being
detected bluewards of around 5800 AA due to a combination of
high background from the bright moon and faint afterglow.
In the red part, the spectrum exhibits four marginal absorption
features, which are consistent with coming from various FeII
transitions at a common redshift of z=2.53.

We acknowledge excellent support from the ESO observing staff
in Paranal, in particular Marcela Espinoza, Cedric Ledoux,
and Stephane Brillant.