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GCN Circular 22348

Subject

GRB 180115A: Swift-BAT refined analysis

Date

2018-01-16T02:02:07Z (6 years ago)

From

Amy Lien at GSFC <amy.y.lien@nasa.gov>

S. D. Barthelmy (GSFC), J. K. Cannizzo (NASA/UMBC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+446 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180115A (trigger #805318)
(Cannizzo et al., GCN Circ. 22335Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 12.040, -15.632 deg which is
  RA(J2000)  =  00h 48m 09.6s
  Dec(J2000) = -15d 37' 55.0"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 57%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~ T+25 s and ends at ~T+70 s. The main peak occurs at ~T+66 s.
T90 (15-350 keV) is 40.9 +- 3.0 sec (estimated error including systematics).

The time-averaged spectrum from T+26.49 to T+70.28 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.66 +- 0.22.  The fluence in the 15-150 keV band is 7.6 +- 1.1 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+65.96 sec in the 15-150 keV band
is 0.6 +- 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/805318/BA/