{
  "bibcode": "2005GCN..3585....1F",
  "body": "D.B. Fox (Caltech), D.A. Frail (NRAO), P.B. Cameron (Caltech), and\nS.B. Cenko (Caltech) report on behalf of the Caltech-NRAO-Carnegie GRB\nCollaboration:\n\n\"We have observed the HETE localization region for GRB050709, a likely\nshort-hard gamma-ray burst (Butler et al., GCN 3570) with the Chandra\nX-ray Observatory + ACIS, in a single 44 ksec observation beginning at\n2005 July 12.2 UT (mean epoch 2.52 days after the burst).  Excluding\nintervals of significant background flares, we retain 38.4 ksec good\ntime.  Performing a standard \"wavdetect\" analysis, we identify three\nsources within the SXC error circle.  The fainter two of these sources\nare very close to each other and are coincident with the bright radio\n(NVSS/20-cm and 8.5 GHz) source identified by Cameron & Frail (GCN\n3578).  The brightest source within the error circle has a total of\n49.5 +/- 8.8 counts (0.3-8.0 keV) and is located at:\n\n    RA 23:01:26.96, Dec -38:58:39.5 (J2000),\n\nwhere we have made a slight (0.4\") adjustment to the native astrometry\nbased on the optical/X-ray coincidence of three other sources in the\nfield, and estimate our positional uncertainty as less than 0.5\".  \n\nThis position is ~1\" distant from an R~20.5 mag point-like object\nvisible in images from the Digitized Sky Survey.  Given that our\nposition is marginally consistent with this object, and that we cannot\nat this time demonstrate significant fading behavior, we caution\nobservers that the source could be revealed to be a coronally-active\nstar or AGN.  Nonetheless, we consider it a reasonable afterglow\ncandidate; in particular, the X-ray flux (~8.4E-15 erg/cm2/s, 2-10\nkeV) is consistent with a ~t**(-1.4) power-law decay from the\nafterglow peak observed by the SXC (assuming this peak reached ~3E-10\nerg/cm2/s, 2-10 keV, at 100 sec after the burst); this flux and decay\nrate would also be consistent with the Swift XRT non-detection (Morgan\net al., GCN 3577).\n\nA particularly intriguing prospect given observations of the\nshort-hard burst GRB050509B (Barthelmy et al., GCN 3385; Prochaska et\nal., GCN 3390) is that the DSS object 1\" distant from this candidate\nafterglow may be the burst host galaxy.\"",
  "circularId": 3585,
  "createdOn": 1121243801000,
  "email": "derekfox@astro.caltech.edu",
  "subject": "GRB050709: Candidate X-ray Afterglow from Chandra",
  "submitter": "Derek Fox at CIT  <derekfox@astro.caltech.edu>",
  "eventId": "GRB 050709"
}