[vsnet-grb-info 10262] GRB 110213A: Bok Telescope Redshift

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11708
SUBJECT: GRB 110213A: Bok Telescope Redshift
DATE:    11/02/13 07:23:19 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko at srl.caltech.edu>

P. A. Milne (U. Arizona) and S. B. Cenko (UC Berkeley) report on behalf of
a larger collaboration:

We have obtained a series of optical spectra of the afterglow of GRB
110213A (D'Elia et al, GCN 11705) with the Boller and Chivens Spectrograph
mounted on the 2.3-m Bok telescope.  Observations began at 05:53 UT (~ 36
minutes after the Swift trigger time) and cover the wavelength range from
~ 4000-8300 A.

We detect a series of strong, narrow absorption features corresponding to
Mg II and Fe II at a common redshift of z = 1.46.  Without the detection
of fine structure lines or a DLA system, we cannot definitively identify
this as the redshift of the GRB host galaxy.  However, the lack of
detection of Lyman alpha absorption down to ~ 4000 A limits the redshift
of the host galaxy to z <~ 2.3.