Skip to main content
New Swift-BAT/GUANO and IceCube Notice Types Available! See news and announcements

GCN Circular 8713

GRB 081222: Gemini-South absorption redshift
2008-12-23T14:58:35Z (15 years ago)
Antonino Cucchiara at PSU <>
A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko  (Berkeley) and E. Berger
(Harvard) report on behalf of a larger collaboration:

Starting at 01:02 UT on 2008 December 23  we observed the optical
counterpart of GRB 081222 (Grupe et al., GCN 8691, Covino  et al.,
GCN 8692 and Updike et al. 8693) using Gemini-South with the GMOS-South
spectrograph (R~1600).
We acquired 2x900s spectra covering the wavelength range 4000A-8000A.

We detect a damped Lyman-alpha system (DLA) at redshift z=2.77.

We also detect several metal absorption features which we interpret as
SiIV(1393,1402), SiII1526 and 1260, SiII*1264, CII1334, CII*1335,
CIV(1548,1550), FeII1608 and NiII(1454) at the same redshift.

In combination with the strong metal absorption features, the detection of
a DLA at z = 2.77 confirms that this is the redshift of GRB 081222 and its
host galaxy.

We thank the Gemini staff, in particular Henry Lee, for conducting
these observations.
Looking for U.S. government information and services? Visit