{
  "bibcode": "2012GCN.13640....1T",
  "body": "E. Troja (NASA/GSFC/UMCP), T. Sakamoto (NASA/GSFC/UMCB),\nN. Gehrels (NASA/GSFC), D. Donato (NASA/GSFC/UMCP),\nand J. L. Racusin (NASA/GSFC) report:\n\nWe observed the field of GRB 120804A (Lien et al., GCN Circ. 13573) with\nthe Chandra ACIS-S starting on August 13, 2012 10:52:08 UT (~9.4 d after\nthe GRB trigger) for a total exposure of 19.8 ks. Within the Swift/XRT\nenhanced position (Osborne et al., GCN Circ. 13577) we clearly detect a\nsource at Ra, Dec = 233.94786, -28.7823 which is equivalent to:\n\nRA (J2000) = 15h 35m 47.49s\nDec (J2000) = -28d 46' 56.3\"\n\nwith an uncertainty of 0.6 arcsec (radius, sys+stat, 90% containment).\nThis position is consistent with the putative host galaxy S1\n(Chornock et al., GCN Circ. 13586).\n\nThe X-ray afterglow is detected at a count rate of (1.6 +/- 0.3)E-03 cts/s\n(0.5-8.0 keV). By using the spectral parameters derived from the Swift/XRT\nobservations (Stroh et al., GCN Circ. 13580) we estimate an observed X-ray\nflux of (1.5 +/-0.3)E-14 erg/cm2/s in the 0.3-10 keV energy band.\nOur measurement is consistent with the power-law decay of ~1.1 reported\nby Stroh et al. (GCN Circ. 13580), and sets a lower limit to the jet-break\ntime of t_j>9 d.\n\n\nWe thank Harvey Tananbaum and the entire Chandra staff for approving and\nrapidly executing this observation.",
  "circularId": 13640,
  "createdOn": 1344947414000,
  "email": "eleonora.troja@nasa.gov",
  "subject": "GRB120804A: Chandra observations and afterglow detection",
  "submitter": "Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>",
  "eventId": "GRB 120804A"
}