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GCN Circular 2628

XRF040701: VLA Observations
2004-07-13T22:07:14Z (20 years ago)
Derek Fox at CIT <>
P.B. Cameron and D.B. Fox (Caltech) with D.A. Frail (NRAO) report on
behalf of a larger collaboration:

"We have made several targeted observations within and near the
localization region for XRF040701 (Barraud et al., GCN 2620) with the
VLA in D-configuration, on July 12, 2004, from 08:19 to 09:48:49 UT.
The chief aim was to provide full coverage of the brighter part of the
Chandra source catalog (Fox, GCN 2626); however, the resulting
pointings provide coverage of approximately 75% of the region at
X-band (8.4 GHz) and approximately 10% of the region in C-band (4.9

We detect five sources within our coverage area, one of which is an
NRAO VLA Sky Survey (NVSS) 1.4-GHz source, and none of which are
coincident with Chandra sources. In addition, we have marginal (~2
sigma) detections at the positions of three Chandra sources.  The
following table reports the VLA source positions, frequency of
detection, and flux in mJy, with uncertainties in the final digits
given in parentheses.  In addition, we note whether the particular
source was detected in the NVSS (Y/N), which has an average RMS noise
level of 0.45 mJy/beam at 1.4 GHz but technically is only complete to
a declination of -40 degrees.

 VLA#  RA            Dec           Freq    Flux     NVSS?
   1   20 47 37.968  -40 15 44.65  8.35   1.01(10)   N
   2   20 47 07.707  -40 15 48.02  8.35   0.76(09)   Y
   3   20 47 35.965  -40 13 34.72  8.35   0.48(10)   N
   4   20 47 52.542  -40 12 36.45  8.35   0.47(10)   N
   5   20 47 29.041  -40 11 28.94  8.35   0.32(09)   N

We note that VLA source #1 is coincident with a bright star-like
source and USNO B-1.0 object from the DSS.

The following table reports our marginal ~2-sigma detections at the
positions of sources from the Chandra catalog.  We give the Chandra ID
number and name from Fox (GCN 2626), the frequency of observation, and
the estimated flux in mJy with uncertainties in the final digits given
in parentheses.  In addition, we indicate whether the source has a
counterpart in the DSS (Y/N).

 Chandra#  Name                    Freq    Flux      DSS?
    2      CXOU J204816.1-401108   8.35   0.22(10)    Y
   16      CXOU J204712.3-401112   8.35   0.19(09)    N
   25      CXOU J204749.9-400627   8.35   0.23(10)    Y 

Chandra source #2, which is associated with a z=0.2146 emission-line
galaxy (Kelson et al., GCN 2627) has a marginal detection in X-band
but not C-band."
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