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GCN Circular 36143

Subject

GRB 240415A: Swift-BAT refined analysis

Date

2024-04-17T02:09:31Z (14 days ago)

From

Mike Moss at NASA GSFC <mikejmoss3@gmail.com>

Via

Web form

M. J. Moss (GSFC), 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),
T. Sakamoto (AGU) (i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240415A (trigger #1221874)
(Moss, et al., GCN Circ. 36108Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 129.197, 73.150 deg which is 
   RA(J2000)  =  08h 36m 47.2s 
   Dec(J2000) = +73d 09' 01.7" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.
 
The mask-weighted light curve displays a bright pulse lasting for ~15 s and 
peaking at ~T0+5 s and another dim pulse of emission at ~T0+30 s. 
The T90 (15-350 keV) is 30.96 +- 3.59 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.70 to T+37.50 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.28 +- 0.13.  The fluence in the 15-150 keV band is 1.6 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+5.09 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
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1221874