GCN Circular 11164
Subject
GRB 100901A: Gemini-N Redshift
Event
Date
2010-09-01T17:02:09Z (15 years ago)
From
Ryan Chornock at Harvard <rchornock@cfa.harvard.edu>
R. Chornock, E. Berger (Harvard), D. Fox (Penn State), A. J. Levan (U. Warwick),
N. R. Tanvir, and K. Wiersema (U. Leicester) report on behalf of a larger
collaboration:
We obtained spectroscopy of the optical afterglow (Immler et al., GCN 11159;
Guidorzi et al., GCN 11160; Ivanov et al., GCN 11161; Klunko et al., GCN 11162)
of GRB 100901A (Immler et al., GCN 11159) using GMOS on the Gemini-North 8-m
telescope starting on 2010 September 1.61 UT. A set of four 400s observations
were obtained covering the wavelength range 3825-6675 Angstroms. Numerous
absorption lines are present. The highest redshift system is at z=1.408, with
many absorptions from Fe II, Al II, and Si II. The presence of several Fe II*
absorptions establishes this as the redshift of the host galaxy of GRB 100901A.
Two intervening systems at z=1.315 and 1.318 also have absorptions from Mg II
and Fe II.
We thank A. Stephens and the Gemini staff for their help in obtaining these
observations.