GRB 240730A: Swift-BAT refined analysis
Abstract
Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240730A (trigger #1245636) (Cenko, et al., GCN Circ. 36976). The BAT ground-calculated position is RA, Dec = 37.841, 59.045 deg which is RA(J2000) = 02h 31m 21.9s Dec(J2000) = +59d 02' 43.5" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 98%. The BAT mask-weighted light curve displays two spectrally soft peaks. The T90 (15-350 keV) is 50.13 +- 7.60 sec (estimated error including systematics). The time-averaged spectrum from T-6.06 to T+53.43 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.50 +- 0.19. The fluence in the 15-150 keV band is 6.8 +- 0.9 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+5.80 sec in the 15-150 keV band is 0.4 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1245636 The long duration and proximity to the Galactic plane raised the initial possibility that this was a Galactic transient. However, its subsequent behavior, including a lack of later BAT detections, is consistent with a GRB, making the Galactic transient interpretation less likely.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- August 2024
- Bibcode:
- 2024GCN.37005....1S