GCN Circular 36657
Subject
EXO 0748-676: Swift-BAT refined analysis
Date
2024-06-10T22:17:46Z (16 days ago)
From
Tyler Parsotan at NASA GSFC <tyler.parsotan@nasa.gov>
Via
email
M. J. Moss (GSFC), S. D. Barthelmy (GSFC),
R. Gupta (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), D. Sadaula (GSFC/UMBC),
T. Sakamoto (AGU)(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of EXO 0748-676 (trigger #1236151)
(D’Elia, et al., GCN Circ. 36653). The BAT ground-calculated position is
RA, Dec = 117.083, -67.777 deg which is
RA(J2000) = 07h 48m 20.0s
Dec(J2000) = -67d 46' 35.5"
with an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 92%.
The mask-weighted lightcurve shows a fast rise exponential decay profile in the
15-25 keV energy range.
T90 (15-350 keV) is 8.06 +- 2.52 sec (estimated error including systematics).
The time-averaged spectrum from T-1.45 to T+7.90 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
5.07 +- 0.86. The fluence in the 15-150 keV band is 7.4 +- 1.7 x 10^-08 erg/cm2.
The 1-sec peak photon flux measured from T+0.90 sec in the 15-150 keV band
is 0.3 +- 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/1236151