{
  "bibcode": "2003GCN..2328....1B",
  "body": "XRF030723(=H2777): Observations with the Chandra X-ray Observatory\n\nN. Butler, P. Ford, G. Ricker, R. Vanderspek, J. Villasenor (MIT); D.\nLamb (U. Chicago); G. Garmire (PSU); L. Piro (CNR); and J.G. Jernigan\n(UCB), on behalf of a Chandra GRB ToO Team,\n\nwrite:\n\nOn 25 July 2003, the Chandra Observatory targeted the field of \nXRF030723, an X-ray flash localized by the HETE satellite (=H2777; \nPrigozhin et al, GCN 2313). The 25 ksec observation spanned the \ninterval 09:52-17:05 UT on 25 July, 51.4 - 59.0 hours after the \nburst. The SXC error circle from Prigozhin et al. was completely \ncontained within the field-of-view of the Chandra ACIS-I array.\n\nWithin the SXC error circle, we detect 3 sources in the 0.5-8 keV band:\n\n#      Chandra Name           RA           DEC         Cts\n1 CXOU J214924.4-274248   21 49 24.421  -27 42 48.00   78\n3 CXOU J214926.9-274146   21 49 26.891  -27 41 45.92   19\n4 CXOU J214928.7-274211   21 49 28.724  -27 42 11.47   16\n\nThe brightest object within the SXC error circle, Chandra Source #1, \nlies 62\" from the center of the SXC error circle, and is within 0.7\" \nof the optical transient reported by Fox et al. (GCN 2323). We \nestimate a position uncertainty of 1.4\" for the Chandra sources. \nAstrometry was performed using six stars from the USNO-A2 catalog.\n\nThe Chandra results provide further evidence that the optical \ntransient reported by Fox et al. (GCN 2323; see also Wood-Vasey et \nal., GCN 2325) and confirmed by Dullighan et al. (GCN 2326) is indeed \nthe counterpart and afterglow of XRF030723.\n\nWe gratefully acknowledge the timely assistance of Roger Brissenden \nand the observatory staff at the Chandra Science Center in arranging \nfor the acquisition and preliminary processing of these data.\n\nThis message may be cited.",
  "circularId": 2328,
  "createdOn": 1059241138000,
  "email": "grr@space.mit.edu",
  "subject": "XRF030723(=H2777): Chandra Observations",
  "submitter": "George Ricker at MIT  <grr@space.mit.edu>"
}