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GCN Circular 33742

Subject

GRB 230506B: Swift-BAT refined analysis

Date

2023-05-07T18:41:10Z (2 years ago)

From

Amy Lien at GSFC <amy.y.lien@nasa.gov>

S. D. Barthelmy (GSFC), S. Dichiara (PSU),
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),
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 230506B (trigger #1167266)
(Dichiara et al., GCN Circ. 33727Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 326.986, 44.514 deg which is
   RA(J2000)  =  21h 47m 56.6s
   Dec(J2000) = +44d 30' 50.9"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 73%.

The mask-weighted light curve shows a multi-peaked structure that
starts at ~T0 and ends at ~T+80 s. The main peak occurs at ~T+11 s.
T90 (15-350 keV) is 61.54 +- 10.89 sec (estimated error
including systematics).

The time-averaged spectrum from T+0.02 to T+76.30 sec is best fit
by a simple power-law model.  The power law index of the time-averaged
spectrum is 1.41 +- 0.11.  The fluence in the 15-150 keV band
is 2.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured
from T+10.60 sec in the 15-150 keV band is 4.6 +- 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/1167266/BA/