GCN Circular 34449
Subject
GRB 230815A: Swift-BAT refined analysis
Date
2023-08-16T16:03:55Z (9 months ago)
From
Tyler Parsotan at NASA GSFC <tyler.parsotan@nasa.gov>
Via
email
S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230815A (trigger #1185505)
(Klingler, et al., GCN Circ. 34434). The BAT ground-calculated position is
RA, Dec = 184.760, -58.067 deg which is
RA(J2000) = 12h 19m 02.4s
Dec(J2000) = -58d 03' 59.5"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 11%.
The mask-weighted light curve shows a strong peak at trigger time with precursor emission
At T-14 sec from trigger. T90 (15-350 keV) is 17.00 +- 7.62 sec (estimated error including systematics).
The time-averaged spectrum from T-14.78 to T+9.22 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.19 +- 0.10. The fluence in the 15-150 keV band is 5.2 +- 0.3 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+0.22 sec in the 15-150 keV band
is 13.7 +- 1.1 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/1185505/BA/