GCN Circular 33933
Subject
GRB 230606A: Swift-BAT refined analysis
Date
2023-06-07T17:04:23Z (a year ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
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 230606A (trigger #1173731)
(Lien et al., GCN Circ. 33921). The BAT ground-calculated position is
RA, Dec = 166.777, 36.504 deg which is
RA(J2000) = 11h 07m 06.4s
Dec(J2000) = +36d 30' 15.6"
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 15%.
The mask-weighted light curve shows two distinct pulses. The first pulse starts
at ~T0 and ends at ~T+4 s. The second pulse starts at ~T+14 s and ends at ~T+16 s.
T90 (15-350 keV) is 16.26 +- 1.29 sec (estimated error including systematics).
The time-averaged spectrum from T-0.26 to T+16.97 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.15 +- 0.30. The fluence in the 15-150 keV band is 1.2 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.92 sec in the 15-150 keV band
is 2.6 +- 0.6 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/1173731/BA/