TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3101
SUBJECT: GRB 050315: Absorption redshift 
DATE:    05/03/16 09:57:54 GMT
FROM:    Edo Berger at Carnegie Obs  <eberger@ociw.edu>

Dan Kelson and Edo Berger (Carnegie Observatories) report:

"Using LDSS3 on Magellan we also obtained a 20-minute spectrum of the
afterglow candidate (GCN 3100).  We find several absorption features which
we identify as AlIII (1854.7 and 1862.8) and SiII (1808.0) at a redshift
of z=1.949.  We conclude that this is the redshift of GRB 050315.

Given a fluence of >2.8e-6 erg/cm^2 (GCN 3099), the isotropic-equivalent
gamma-ray energy is > 2.6e52 erg."