GCN Circular 18527
Subject
GRB 151029A: Swift-BAT refined analysis
Date
2015-10-29T12:22:22Z (9 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL)
(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 151029A (trigger #662086)
(Ukwatta, et al., GCN Circ. 18522). The BAT ground-calculated position is
RA, Dec = 38.537, -35.356 deg, which is
RA(J2000) = 02h 34m 09.0s
Dec(J2000) = -35d 21' 21.7"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 41%.
The mask-weighted light curve shows two overlapping peaks starting
at ~T-2 sec, peaking at ~T+1 se, and ending at ~T+10 sec.
T90 (15-350 keV) is 8.95 +- 2.32 sec (estimated error including systematics).
The time-averaged spectrum from T-1.10 to T+10.47 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 0.49 +- 1.08,
and Epeak of 33.9 +- 6.9 keV (chi squared 53.8 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 3.9 +- 0.6 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T-0.15 sec in the 15-150 keV band is
1.8 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index
of 2.16 +- 0.19 (chi squared 64.3 for 57 d.o.f.). 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/662086/BA/