GRB 200529A: Swift-BAT refined analysis

Using the data set from T-61 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 200529A (trigger #974942) (V. D'Elia, et al., GCN Circ. 27845). The BAT ground-calculated position is RA, Dec = 238.756, -11.076 deg which is RA(J2000) = 15h 55m 01.3s Dec(J2000) = -11d 04' 34.5" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 50%. The mask weighted light curve shows a complex structure. The overall structure starts at ~T-5 s and lasts till ~T+100 s. T90 (15-350 keV) is 79.57 +- 7.26 sec (estimated error including systematics). The time-averaged spectrum from T-1.24 to T+92.92 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.89 +- 0.10. The fluence in the 15-150 keV band is 3.2 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+1.58 sec in the 15-150 keV band is 1.8 +- 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/974942/BA/