TITLE: GCN CIRCULAR NUMBER: 15234 SUBJECT: GRB 130919A, Swift-BAT refined analysis DATE: 13/09/20 02:27:56 GMT FROM: Hans Krimm at NASA-GSFC A. Y. Lien (NASA/GSFC/ORAU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 130919A (trigger #571271) (Krimm, et al., GCN Circ. 15232). The BAT ground-calculated position is RA, Dec = 207.281, -10.353 deg which is RA(J2000) = 13h 49m 07.5s Dec(J2000) = -10d 21' 11.0" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 77%. The burst came into the BAT field of view at ~T-60 seconds, following a pre-planned slew and another slew took it out of the field at around T+215 seconds. mask-weighted light curve shows a broad peak from T-30 s to T+70 s, with at least six subpeaks superimposed. T90 (15-350 keV) is 97.3 +- 25.1 sec (estimated error including systematics). The time-averaged spectrum from T-20.15 to T+108.07 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.54 +- 0.73, and Epeak of 71.7 +- 31.8 keV (chi squared 58.75 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T-6.49 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.52 +- 0.14 (chi squared 65.60 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/571271/BA/