TITLE: GCN CIRCULAR NUMBER: 11811 SUBJECT: GRB 110319A: Swift-BAT refined analysis DATE: 11/03/19 14:28:25 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), A. Melandri (INAF-OAB), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 110319A (trigger #449578) (Melandri, et al., GCN Circ. 11807). The BAT ground-calculated position is RA, Dec = 356.510, -66.008 deg, which is RA(J2000) = 23h 46m 02.4s Dec(J2000) = -66d 00' 28.7" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows two overlapping peaks starting at ~T_zero, peaking at ~T+5 and ~T+13 sec, and ending at ~T+30 sec. T90 (15-350 keV) is 19.3 +- 1.6 sec (estimated error including systematics). The time-averaged spectrum from T-0.3 to T+31.3 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.31 +- 0.43, and Epeak of 21.9 +- 7.0 keV (chi squared 54.2 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+13.10 sec in the 15-150 keV band is 2.2 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 2.55 +- 0.08 (chi squared 86.5 for 57 d.o.f.). 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/449578/BA/