GCN Circular 5944
Subject
GRB 061201: Magellan Redshift of nearby Abell cluster
Date
2006-12-20T07:42:22Z (18 years ago)
From
Josh Bloom at UC Berkeley <jbloom@astron.berkeley.edu>
S. Blondin, G. Narayan (Harvard/CfA), J. S. Bloom (UC Berkeley), H-
W. Chen (U Chicago), R. P. Kirshner, P. Challis, M. Hicken, M.
Modjaz, A. Friedman, M. Wood-Vasey (Harvard/CfA), and J. X. Prochaska
(UC Santa Cruz) report on behalf of a larger collaboration:
"The final X-ray afterglow position (Perri et al. 2006; GCN 5885) of
the short-hard GRB 061201 (Marshall et al. 2006; GCN 5881) lies 8.5
arcmin from the center of the rich Abell cluster 995 (Bloom 2006; GCN
5880). On 13 December 2006 UT, we obtained several spectra of bright
apparent cluster members with the LDSS-3 instrument mounted on the
Magellan Clay 6.5m Telescope in Chile. We find the following
redshifts based upon a preliminary inspection of the spectra:
RA (J2000) DEC(J2000)
===========================
object A: z=0.239 22:08:32.1 -74:34:47
object B: z=0.235 22:09:37.1 -74:26:39
object D: z=0.238 22:09:05.3 -74:29:29
Based on this, we claim a redshift of z=~0.237 for Abell 995 and note
that while the GRB is not yet definitively associated with a cluster
member galaxy, this redshift (and hence the implied energetics of the
event) are very similar to the putative redshifts of short-hard GRBs
050509b (z=0.225), 050724 (z=0.258), and 060502b (z=0.287)."
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