GCN Circular 3399
Subject
GRB 050509b: Physical Properties of the Candidate Host galaxy
Date
2005-05-10T00:53:14Z (19 years ago)
From
Hsiao-Wen Chen at MIT/CSR <hchen@space.mit.edu>
Jason X. Prochaska (UCO/Lick Obs.), J. S. Bloom (UCB), H.-W. Chen (MIT), &
K. Hurley (UCB) report on behalf of the GRAASP collaboration:
"We have further analyzed the longslit spectrum obtained for the candidate host
galaxy of GRB 050509b Bloom et al. GCN 3386) by Prochaska et al. (GCN 3390),
using Keck/DEIMOS. We estimate a more precise redshift of the galaxy at z =
0.2249 +/- 0.0008 by cross-correlating the spectrum with galaxy templates from
SDSS. At this redshift, the host has an intrinsic K-band luminosity of
~ 1.6 x 10^11 L_sun as derived based on its 2MASS photometry of K = 14.1 mag.
We attempt to constrain the underlying dark matter halo mass of the galaxy
based on the observed absorption line profiles. Using the Ca H&K doublet, we
estimate a velocity dispersion of ~ 340 km/sec. This corresponds to an
enclosed dynamical mass of 7.2 x 10^11 h^{-1} M_sun at the radius of the
OT r = 26.6 h^-1 kpc. The spectrum of the galaxy is presented at
http://www.graasp.org/Data/050509b.
This message can be cited."