GRB 200228B: Swift-BAT refined analysis
Abstract
Using the data set from T-240 to T+297 sec from the recent telemetry downlink, we report further analysis of BAT GRB 200228B (trigger #958733) (Laha et al., GCN Circ. 27254). The BAT ground-calculated position is RA, Dec = 252.007, 16.964 deg which is RA(J2000) = 16h 48m 01.8s Dec(J2000) = +16d 57' 50.3" with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 31%. The mask-weighted light curve shows a weak pulse that starts at ~T-1 s, peaks at ~T+2 s, and ends at ~T+7 s. T90 (15-350 keV) is 7.37 +- 1.58 sec (estimated error including systematics). The time-averaged spectrum from T-0.84 to T+6.97 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.27 +- 0.36. The fluence in the 15-150 keV band is 3.0 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+1.32 sec in the 15-150 keV band is 1.0 +- 0.4 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/958733/BA/
- Publication:
-
GRB Coordinates Network
- Pub Date:
- February 2020
- Bibcode:
- 2020GCN.27273....1M