TITLE: GCN CIRCULAR NUMBER: 35781 SUBJECT: GRB 240222A: Swift-BAT refined analysis DATE: 24/02/23 03:51:30 GMT FROM: Amy <yarleen@gmail.com> H. A. Krimm (NSF), S. D. Barthelmy (GSFC), P. D'Avanzo (INAF-OAB), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), T. Sakamoto (AGU) (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 240222A (trigger #1216804) (D'Avanzo et al., GCN Circ. 35770). The BAT ground-calculated position is RA, Dec = 143.209, -68.034 deg which is RA(J2000) = 09h 32m 50.2s Dec(J2000) = -68d 02' 03.7" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 94%. The mask-weighted light curve shows a main pulse that starts at ~T-0.4 s, peaks at ~T0, and ends at ~T+1.4 s. In addition, there is a small precursor pulse at ~T-2.7 s. T90 (15-350 keV) is 3.94 +- 2.35 sec (estimated error including systematics). The time-averaged spectrum from T-2.70 to T+1.37 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.75 +- 0.23. The fluence in the 15-150 keV band is 2.5 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.20 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1216804/ View this GCN Circular online at https://gcn.nasa.gov/circulars/35781. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...