{
  "bibcode": "2006GCN..5882....1M",
  "body": "C. Markwardt (GSFC/UMD), L. Barbier (GSFC), S.D. Barthelmy (GSFC),\nJ. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),\nH. Krimm (GSFC/USRA), F.E. Marshall (NASA/GSFC), D. Palmer (LANL),\nA. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS),\nM. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)\non behalf of the Swift-BAT team:\n \nUsing the data set from T-239 to T+366 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 061201 (trigger #241840)\n(Marshall, et al., GCN Circ. 5881).  The BAT ground-calculated position\nis RA, Dec = 332.079, -74.569 deg which is \n   RA(J2000)  =  22h 08m 19.0s \n   Dec(J2000) = -74d 34'  6.6\" \nwith an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 48%.\n \nThe mask-weighted lightcurve shows two main peaks separated by ~0.7 sec,\nthe first starting at T+0 sec, and the second ending at T+1.1 sec.\nA visual scan of the lightcurve (from T+2 to T+300 sec) places an\nupper limit of 0.01 ph/cm2/sec for any extended emission.\nT90 (15-350 keV) is 0.8 +- 0.1 sec (estimated error including systematics).\n \nThe time-averaged spectrum from T+0.0 to T+0.9 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum\nis 0.81 +- 0.15.  The fluence in the 15-150 keV band is 3.3 +- 0.3 x 10^-7 erg/cm2.\nThe 1-sec peak photon flux measured from T-0.05 sec in the 15-150 keV\nband is 3.9 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90%\nconfidence level. \n\nThe burst shows significant hard to soft spectral evolution.  A fit to the\nfirst peak (T+0.0 to T+0.7) gives a simple power law index of 0.57 +/- 0.15,\nwhile a fit to the second peak (T+0.7 to T+0.9) has a power law index of\n2.10 +/- 0.35.  Similarly, the light curve shows that the emission in the\n15-25 keV channel extends to T+1.5 sec, while emission in the\n100-350 keV channel lasts only until ~T+0.6 sec.",
  "circularId": 5882,
  "createdOn": 1165008620000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 061201, Swift-BAT refined analysis of the SHB",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 061201"
}