GRB 220730A: Swift-BAT refined analysis

Using the data set from T-240 to T+700 sec from the recent telemetry downlink, we report further analysis of BAT GRB 220730A (trigger #1118357) (Dichiara, et al., GCN Circ. 32431). The BAT ground-calculated position is RA, Dec = 224.988, -69.496 deg which is RA(J2000) = 14h 59m 57.1s Dec(J2000) = -69d 29' 44.5" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 60%. The mask-weighted light curve shows a single FRED-shaped pulse from approximately T-0.05 to T+0.25 seconds. T90 (15-350 keV) is 0.19 +- 0.20 sec (estimated error including systematics). The time-averaged spectrum from T-0.04 to T+0.28 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.61 +- 0.25. The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.35 sec in the 15-150 keV band is 1.6 +- 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/1118357/BA/