GRB 220412A: Swift-BAT refined analysis

Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 220412A (trigger #1102281) (Klingler et al. GCN Circ. 31881). The BAT ground-calculated position is RA, Dec = 123.975, 30.336 deg which is RA(J2000) = 08h 15m 54.0s Dec(J2000) = +30d 20' 08.5" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 92%. The BAT light curve showed a complex structure with a duration of about 20 sec. The peak count rate was ~900 counts/sec (15-350 keV), at ~1 sec after the trigger. T90 (15-350 keV) is 41.66 +- 7.00 sec (estimated error including systematics). The time-averaged spectrum from T-11.07 to T+38.00 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.53 +- 0.21. The fluence in the 15-150 keV band is 5.9 +- 0.9 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+6.88 sec in the 15-150 keV band is 0.5 +- 0.1 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/1102281/BA/