GCN Circular 2934
Subject
Second Epoch VLA observations of SGR 1806-20
Date
2005-01-04T17:32:20Z (22 years ago)
From
Patrick B. Cameron at Caltech <pbc@astro.caltech.edu>
P. B. Cameron (Caltech) and S. R. Kulkarni (Caltech) report:
"We observed a second epoch of the position of SGR 1806-20 with the Very
Large Array (VLA) in A-configuration on 2005 Jan 4.59 UT (t ~ 7.7 days
after the giant flare, GCN #2920). We again detect a radio source
coincident with the X-ray position reported by Kaplan et al. (2002, ApJ,
564, 935) at the approximate freqeuncies and flux densities listed below.
Freq (GHz) Flux density (mJy)
--------------------------------
1.43 128 +/- 5
4.86 62 +/- 2
8.46 37 +/- 5
Error Bars are 1 sigma. The combination of these measurements with those
reported 2005 Jan 03 (GCN #2928, #2929, 2930, ATEL 373) suggest a decay
exponent (F ~ t^beta) of beta = -2.2 at 1.4 GHz. The spectral index
(F ~ nu^alpha) has remained constant over the two epochs with alpha =
-0.74 and -0.68.
The National Radio Astronomy Observatory is operated by Associated
Universities, Inc., under cooperative agreement with the National Science
Foundation."