TITLE: GCN CIRCULAR NUMBER: 32612 SUBJECT: GRB 220930A: Swift-BAT refined analysis DATE: 22/10/02 03:35:10 GMT FROM: Sibasish Laha at GSFC sibasish.laha@nasa.gov
S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (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 220930A (trigger #1125809) (Cenko et al., GCN Circ. 32603). The BAT ground-calculated position is RA, Dec = 64.725, 13.353 deg which is RA(J2000) = 04h 18m 54.0s Dec(J2000) = +13d 21' 12.0" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 11%.
The BAT light curve showed a complex structure with a duration of about 200 sec. T90 (15-350 keV) is 180.47 +- 104.20 sec (estimated error including systematics).
The time-averaged spectrum from T-0.42 to T+235.67 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.59 +- 0.13. The fluence in the 15-150 keV band is 5.5 +- 0.4 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-0.31 sec in the 15-150 keV band is 6.2 +- 1.0 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/1125809/BA/