GCN Circular 10390
Subject
GRB 100206A: PAIRITEL Photometry of Host Candidate
Event
Date
2010-02-07T11:00:55Z (17 years ago)
From
Adam Morgan at U.C. Berkeley <qmorgan@gmail.com>
A. N. Morgan, B. E. Cobb, J. S. Bloom, S. B. Cenko, D. A. Perley, A.
A. Miller, M. Modjaz, C. R. Klein (UC Berkeley), report:
We have imaged the field of the short-hard GRB 100206A (Krimm et al.,
GCN 10376) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona.
Observations began at 2010-02-07 02:37:50 UT (~13.1 hours after the
burst). The potential host galaxy (Miller et al., GCN 10377) is
clearly detected in mosaics taken simultaneously in the J, H, and Ks
filters (effective exposure time of 2293 seconds). The preliminary
photometry yields:
exp(s) filt mag
==============================
2293 J 18.35 +/- 0.07
2293 H 17.55 +/- 0.08
2293 Ks 16.56 +/- 0.08
==============================
A preliminary estimate of the metallicity from the Halpha and [N II]
line ratios suggest a super-solar metallicity (~1.5 solar metallicity,
using Asplund 2009 for Solar oxygen abundance). At a redshift of z =
0.41 (Cenko et al., GCN 10389), and assuming a Lambda-CDM cosmology
with H_0=74 km/s/Mpc, Omega_M=0.27 and Omega_Lambda=0.73, we calculate
the distance modulus to be 41.65 mag, which implies a rest-frame
H-band magnitude of about -25 mag. This extreme luminosity, coupled
with what appears to be strong optical reddening (Cenko et al., GCN
10389) suggests that this galaxy is a luminous infrared galaxy
(LIRG/ULIRG). While the physical connection to GRB 100206A has not
been definitively established, the probability of a chance coincidence
of such a galaxy with a SHB is low, providing an a posterori argument
for a physical connection.
All magnitudes given in the Vega system, calibrated to 2MASS. No
correction for Galactic extinction has been made to the above reported
values.