GCN Circular 14693
Subject
GRB 130521A, Swift-BAT refined analysis
Date
2013-05-22T14:15:36Z (12 years ago)
From
Hans Krimm at NASA-GSFC <hans.krimm@nasa.gov>
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), C. Pagani (U Leicester),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
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 130521A (trigger #556344)
(Pagani, et al., GCN Circ. 14691). The BAT ground-calculated position is
RA, Dec = 87.568, 14.470 deg which is
RA(J2000) = 05h 50m 16.3s
Dec(J2000) = +14d 28' 10.8"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 67%.
The mask-weighted light curve shows a single peak starting at T-2 sec, peaking
at T+0 sec and falling to near background by T+4 sec, followed by a weak tail
out to approximately T+12 sec. At around T+120 sec, the source moved out of the
field of view due to a pre-planned slew to another target. T90 (15-350 keV) is
11.0 +- 2.4 sec (estimated error including systematics).
The time-averaged spectrum from T-0.64 to T+12.64 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.11 +- 0.20. The fluence in the 15-150 keV band is 4.2 +- 0.5 x 10^-07
erg/cm2. The 1-sec peak photon flux measured from T-0.14 sec in the 15-150 keV
band is 1.9 +- 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/556344/BA/