TITLE: GCN CIRCULAR NUMBER: 35387 SUBJECT: GRB 231216A: Swift-BAT refined analysis DATE: 23/12/17 05:01:41 GMT FROM: Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp> H. A. Krimm (NSF), S. D. Barthelmy (GSFC), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), T. Sbarrato (INAF-OAB), M. Stamatikos (OSU) (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 231216A (trigger #1202749) (Sbarrato, et al., GCN Circ. 35378). The BAT ground-calculated position is RA, Dec = 39.778, 33.614 deg which is RA(J2000) = 02h 39m 06.6s Dec(J2000) = +33d 36' 48.9" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 59%. The mask-weighted light curve shows a structure of multiple pulses. The emission starts from T-5 s, peaks at T0 and ends at T+60 s. T90 (15-350 keV) is 51.2 +- 3.1 sec (estimated error including systematics). The time-averaged spectrum from T-1.12 to T+51.39 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.63 +- 0.20. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.51 sec in the 15-150 keV band is 1.8 +- 0.3 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/1202749/BA/ View this GCN Circular online at https://gcn.nasa.gov/circulars/35387. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...