TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2628 SUBJECT: XRF040701: VLA Observations DATE: 04/07/13 22:07:14 GMT FROM: 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 GHz). 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."