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GCN Circular 41083

Subject

GRB 250706A: Swift-BAT refined analysis

Event

GRB 250706A

Date

2025-07-13T21:01:31Z (a day ago)

From

Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>

Via

Web form

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), R. Gupta (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), M. J. Moss (GSFC), T. Parsotan (GSFC),
D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU)
(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 250706A (trigger #1330958)
(Moss, et al., GCN Circ. 40988Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 284.011, 32.327 deg which is
   RA(J2000)  =  18h 56m 02.7s
   Dec(J2000) = +32d 19' 36.8"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.

The mask-weighted light curve shows a single-peak structure that starts at
~T-1 s, peaks at ~T+2 s, and ends at ~T+40 s.
T90 (15-350 keV) is 31.9 +- 7.2 sec (estimated error including systematics).

The time-averaged spectrum from T0 to T+40 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.34 +- 0.17.  The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.93 sec in the 15-150 keV band
is 1.3 +- 0.3 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/1330958