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GCN Circular 15750

Subject

GRB 140118A, Swift-BAT refined analysis

Date

2014-01-18T15:15:04Z (10 years ago)

From

Hans Krimm at NASA-GSFC <hans.a.krimm@nasa.gov>

A. Y. Lien (NASA/UMBC), S. D. Barthelmy (GSFC),  W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(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 BAT GRB 140118A (trigger #584136)
(Krimm, et al., GCN Circ. 15748Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 330.999, -17.937 deg which is
    RA(J2000)  =  22h 03m 59.8s
    Dec(J2000) = -17d 56' 14.1"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 41%. The mask-weighted light curve shows a
double-peaked structure of two triangular shaped peaks.  The first
runs from T-70 to T-20 and the second, stronger peak from T-20 to T+30.
T90 (15-350 keV) is 84.15 +- 10.79 sec (estimated error including systematics).

The time-averaged spectrum from T-73.61 to T+30.87 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.87 +- 0.13.  The fluence in the 15-150 keV band is 2.6 +- 0.2 x 10^-6 erg/cm2. 
The 1-sec peak photon flux measured from T+2.98 sec in the 15-150 keV band
is 1.9 +- 0.3 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/584136/BA/