[vsnet-grb-info 4290] GRB070208: Absorption and emission redshift from Gemini

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6083
SUBJECT: GRB070208: Absorption and emission redshift from Gemini
DATE:    07/02/08 20:55:39 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara at astro.psu.edu>

A. Cucchiara (PSU), D. B. Fox (PSU), S. B. Cenko (Caltech) and
P. A. Price (Hawaii) report on behalf of a larger collaboration:

"We observed the optical afterglow (Guidorzi et al., GCN 6077, Fox et
al., GCN 6078) of GRB 070208 (Sato et al., GCN 6074) with the
Gemini-North telescope + Gemini Multi-Object Spectrograph in four
1800-s integrations with mean epoch 11:37 UT on 8 Feb 2007
(approximately 2.5 hours after the burst).  Our spectral coverage is
4000-8300 A.  The bright nearby galaxy seen in archival images (e.g.,
Mirabal & Halpern, GCN 6075) does not fall within our slit.

At the afterglow position we observe a strong [OII] (3727 A) emission
line at redshift z=1.165 superposed on the afterglow continuum, along
with multiple metal absorption features consistent with this redshift,
including: the MgII (2796.4 A, 2803.5 A) doublet, FeII (2600.5 A), and
MnII (2576.9 A).

We conclude that the redshift of GRB 070208 and its underlying host
galaxy is z=1.165."