TITLE: GCN CIRCULAR NUMBER: 36543 SUBJECT: GRB 240523A: Swift-BAT refined analysis DATE: 24/05/26 19:14:44 GMT FROM: Amy <yarleen@gmail.com> A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU), M. H. Siegel (PSU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240523A (trigger #1230423) (Siegel et al., GCN Circ. 36536). The BAT ground-calculated position is RA, Dec = 33.537, -22.053 deg which is RA(J2000) = 02h 14m 08.9s Dec(J2000) = -22d 03' 10.6" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 47%. The mask-weighted light curve shows a multi-peaked structure that starts at ~T-6 s and ends at ~T+46 s. The main peak occurs at ~T+1 s. T90 (15-350 keV) is 41.93 +- 8.66 sec (estimated error including systematics). The time-averaged spectrum from T-6.37 to T+46.30 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.07 +- 0.20. The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.18 sec in the 15-150 keV band is 1.0 +- 0.3 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/1230423 View this GCN Circular online at https://gcn.nasa.gov/circulars/36543. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...