TITLE: GCN CIRCULAR NUMBER: 12539 SUBJECT: GRB 111107A: Swift-BAT refined analysis DATE: 11/11/07 13:02:54 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. H. Siegel (PSU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 111107A (trigger #507185) (Siegel, et al., GCN Circ. 12534). The BAT ground-calculated position is RA, Dec = 129.487, -66.520 deg, which is RA(J2000) = 08h 37m 56.8s Dec(J2000) = -66d 31' 12.0" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 71%. The mask-weighted light curve shows a FRED peak starting at ~T-1 sec, peaking at ~T+2 sec, and returning to baseline at ~T+55 sec. At the 2-sigma level, there is a possible peak from T+130 to T+180 sec. There is no hint of a peak in the T+250 to T+400 sec range corresponding to the flare seen in the XRT afterglow lightcurve. T90 (15-350 keV) is 26.6 +- 6.6 sec (estimated error including systematics). The time-averaged spectrum from T-0.06 to T+32.83 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.49 +- 0.14. The fluence in the 15-150 keV band is 8.8 +- 0.8 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+2.16 sec in the 15-150 keV band is 1.2 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/507185/BA/