TITLE: GCN CIRCULAR NUMBER: 35622 SUBJECT: GRB 240123A: Swift-BAT refined analysis DATE: 24/01/24 18:12:15 GMT FROM: Amy <yarleen@gmail.com> T. Parsotan (GSFC), S. D. Barthelmy (GSFC), A. D'Ai (INAF-IASFPA), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+820 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240123A (trigger #1210276) (D'Ai, et al., GCN Circ. 35602). The BAT ground-calculated position is RA, Dec = 199.287, 60.607 deg which is RA(J2000) = 13h 17m 08.9s Dec(J2000) = +60d 36' 25.6" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 31%. The mask-weighted light curve shows some weak emission with complex structures that starts at ~T0 and ends at ~T+140 s. The main peak occurs at ~T+5 s. T90 (15-350 keV) is 115.30 +- 54.93 sec (estimated error including systematics). The time-averaged spectrum from T-0.69 to T+140.46 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.69 +- 0.23. The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+5.49 sec in the 15-150 keV band is 1.1 +- 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/1210276/BA/ View this GCN Circular online at https://gcn.nasa.gov/circulars/35622. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...