{
  "subject": "GRB 111209A, Swift-BAT refined analysis",
  "eventId": "GRB 111209A",
  "bibcode": "2011GCN.12640....1P",
  "createdOn": 1323457092000,
  "circularId": 12640,
  "submitter": "Takanori Sakamoto at NASA/GSFC  <takanori@milkyway.gsfc.nasa.gov>",
  "email": "takanori@milkyway.gsfc.nasa.gov",
  "body": "D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),\nJ. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),\nH. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), T. Sakamoto (GSFC/UMBC),\nG. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)\n(i.e. the Swift-BAT team):\n\nUsing the data set from the recent telemetry downlink, we report further \nanalysis of BAT GRB 111209A (trigger #509336 and #509337) \n(Hoversten, et al., GCN Circ. 12632).  The BAT ground-calculated position \nusing the event data of trigger #509337 (on-axis observation) \nis RA, Dec = 14.350, -46.799 deg which is \n\n RA(J2000)  =  00h 57m 24.1s \n Dec(J2000) = -46d 47' 57.1\" \n\nwith an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 100%.\n\nThe mask-weighted light curve shows an excess rate already around T-150 s \nwhen the spacecraft settled to the pre-planned target (T is the BAT trigger \ntime of #509336, which is 07:12:08.3 UT).  A gradual increase in the rate \ncontinues up to T+850s.  And then, the rate started to decay.  The positive \nrate is still seen at T+1400 s where the end of the event data.  Further \nanalysis using the BAT survey data is on-going to address the duration of \nthis event detected by BAT.   \n\nThe time-averaged spectrum from 358 to 1337 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.48 +- 0.03.  The fluence in the 15-150 keV band measured during this \ntime interval is 3.6 +- 0.1 x 10^-05 erg/cm2.  The 1-sec peak photon flux \nmeasured from T+824 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec.  \nAll the quoted errors are at the 90% confidence level. \n\nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/509336/BA/\nhttp://gcn.gsfc.nasa.gov/notices_s/509337/BA/"
}