TITLE: GCN CIRCULAR NUMBER: 19328 SUBJECT: GRB 160419A, Swift-BAT refined analysis DATE: 16/04/21 12:58:28 GMT FROM: Amy Lien at GSFC J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160419A (trigger #683383) (Markwardt et al., GCN Circ. 19326). The BAT ground-calculated position is RA, Dec = 16.418, -27.341 deg which is RA(J2000) = 01h 05m 40.3s Dec(J2000) = -27d 20' 28.7" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 16%. The mask-weighted light curve shows a triangle-shaped, single-peaked structure that starts at ~ T-4 s, peaks at ~T0, and ends at ~T0+8 s. T90 (15-350 keV) is 8.8 +- 1.1 sec (estimated error including systematics). The time-averaged spectrum from T-4.5 to T+8.5 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.76 +- 0.33, and Epeak of 107.1 +- 35.2 keV (chi squared 40.46 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.5 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+0.00 sec in the 15-150 keV band is 8.9 +- 0.7 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.40 +- 0.07 (chi squared 53.01 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/683383/BA/