GCN Circular 34297
Subject
GRB 230723B: Swift-BAT refined analysis
Date
2023-07-30T13:50:12Z (9 months ago)
From
Tyler Parsotan at NASA GSFC <tyler.parsotan@nasa.gov>
Via
Web form
T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+60 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230723B (trigger #1180410)
(Page, et al., GCN Circ. 34234). The BAT ground-calculated position is
RA, Dec = 250.391, -5.319 deg which is
RA(J2000) = 16h 41m 33.8s
Dec(J2000) = -05d 19' 08.1"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.
The light curve shows a fast rise exponential decay type profile.
T90 (15-350 keV) is 6.64 +- 0.81 sec (estimated error including systematics).
The time-averaged spectrum from T-0.22 to T+7.94 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 1.09 +- 0.38,
and Epeak of 65.9 +- 15.8 keV (chi squared 41.57 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 1.7 +- 0.1 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+1.64 sec in the 15-150 keV band is
5.1 +- 0.5 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.77 +- 0.08 (chi squared 52.21 for 57 d.o.f.). 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/1180410/BA/