GCN Circular 13880
Subject
GRB 121017A: Swift-BAT refined analysis
Date
2012-10-18T02:26:15Z (12 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
D. Grupe (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 121017A (trigger #536172)
(Grupe, et al., GCN Circ. 13875). The BAT ground-calculated position is
RA, Dec = 288.820, -1.602 deg, which is
RA(J2000) = 19h 15m 16.8s
Dec(J2000) = -01d 36' 07.3"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.
The mask-weighted light curve a single peak starting at ~T-3 sec, peaking
at ~T+1 sec, and ending at ~T+5 sec. T90 (15-350 keV) is 4.2 +- 0.5 sec
(estimated error including systematics).
The time-averaged spectrum from T-2.72 to T+2.53 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.74 +- 0.17. The fluence in the 15-150 keV band is 6.6 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.31 sec in the 15-150 keV band
is 3.3 +- 0.4 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/536172/BA/