TITLE: GCN CIRCULAR NUMBER: 35385 SUBJECT: GRB 231214A: Swift-BAT refined analysis DATE: 23/12/17 04:55:15 GMT FROM: Takanori Sakamoto at AGU M. Stamatikos (OSU), S. D. Barthelmy (GSFC), R. Brivio (INAF-OAB), H. A. Krimm (NSF), 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) (i.e. the Swift-BAT team): Using the data set from T-35 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 231214A (trigger #1202386) (Brivio, et al., GCN Circ. 35335). The BAT ground-calculated position is RA, Dec = 305.666, -72.432 deg which is RA(J2000) = 20h 22m 39.7s Dec(J2000) = -72d 25' 54.3" with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 39%. The mask-weighted light curve shows two bright overlapping peaks. The first peak starts from T-5 s, peaks at T+1 s and ends at T+10 s. The second peak starts from T+10 s, peaks at T+12 s and ends at T+25 s. T90 (15-350 keV) is 27.8 +- 7.3 sec (estimated error including systematics). The time-averaged spectrum from T-5.37 to T+49.42 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.87 +- 0.23, and Epeak of 167 +- 94 keV (chi squared 60.53 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 9.6 +- 0.3 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+12.57 sec in the 15-150 keV band is 11.3 +- 0.6 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.25 +- 0.05 (chi squared 69.34 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/1202386/BA/