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GCN Circular 35473

Subject

GRB 240101A: Swift-BAT refined analysis

Date

2024-01-03T14:06:48Z (4 months ago)

From

Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>

Via

A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC),  S. B. Cenko (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC),
M. J. Moss (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-10 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240101A (trigger #1205708)
(Cenko, et al., GCN Circ. 35448Not found
 
 
).  The trigger time, which was unavailable in the
first circular was 2024-01-01 at 14:20:17.331 UTC.  The BAT ground-calculated position is
RA, Dec = 10.289, 8.540 deg which is
   RA(J2000)  =  00h 41m 09.5s
   Dec(J2000) = +08d 32' 25.3"
with an uncertainty of 3.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 66%.

The mask-weighted light curve shows a weak, complex structure lasting from
About T-5 to T+10 seconds.  T90 (15-350 keV) is 15.8 +- 6.1 sec (estimated error
including systematics).

The time-averaged spectrum from T-1.94 to T+20.28 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.03 +- 0.34.  The fluence in the 15-150 keV band is 3.3 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+2.11 sec in the 15-150 keV band
is 0.9 +- 0.2 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/1205708/BA/