[vsnet-grb-info 13213] GRB 130502A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14550
SUBJECT: GRB 130502A: Swift-BAT refined analysis
DATE:    13/05/04 01:58:01 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), A. Y. Lien (NASA/GSFC/ORAU),
T. Sakamoto (AGU), C. B. Markwardt (GSFC), W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
D. M. Palmer (LANL), G. Sato (ISAS), M. Stamatikos (OSU),
E. Troja (NASA/GSFC/UMCP), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 130502A (trigger #554996)
(Troja, et al., GCN Circ. 14527).  The BAT ground-calculated position is
RA, Dec = 138.579, -0.134 deg, which is
   RA(J2000)  =  09h 14m 19.1s
   Dec(J2000) = -00d 08' 04.2"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 47%.

The mask-weighted light curve consists a single FRED pulse starting at
~T-0.3 sec, peaking at ~T+0.1 sec, and returning to baseline at ~T+4 sec.
T90 (15-350 keV) is 3.0 +- 0.3 sec (estimated error including systematics).

The time-averaged spectrum from T-0.19 to T+3.20 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.78 +- 0.16.  The fluence in the 15-150 keV band is 3.8 +- 0.4 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T-0.21 sec in the 15-150 keV band
is 2.9 +- 0.3 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/554996/BA/