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GCN Circular 14028

Subject

GRB 121201A: Swift-BAT refined analysis

Date

2012-12-01T18:45:12Z (12 years ago)

From

Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC),
T. N. Ukwatta (MSU), V. N. Yershov (UCL-MSSL)
(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 121201A (trigger #540178)
(Yershov, et al., GCN Circ. 14025Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 13.473, -42.929 deg, which is 
   RA(J2000)  =  00h 53m 53.6s 
   Dec(J2000) = -42d 55' 45.9" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows 3 main peaks starting at ~T-23,
peaking at ~T-18, -8, & +4 sec, and ending at ~T+55 sec.  T90 (15-350 keV) is
85 +- 21 sec (estimated error including systematics).
 
The time-averaged spectrum from T-24.00 to T+71.00 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.90 +- 0.21.  The fluence in the 15-150 keV band is 7.8 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-9.00 sec in the 15-150 keV band
is 0.8 +- 0.1 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/540178/BA/