[vsnet-grb-info 15447] GRB 140824A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16736
SUBJECT: GRB 140824A: Swift-BAT refined analysis
DATE:    14/08/24 17:21:26 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm at nasa.gov>

A. Y. Lien (NASA/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), 
A. P. Beardmore (U Leicester), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+714 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 140824A (trigger #610501)
(Beardmore, et al., GCN Circ. 16732).  The BAT ground-calculated position is
RA, Dec = 206.627, 33.285 deg which is
    RA(J2000)  =  13h 46m 30.4s
    Dec(J2000) = +33d 17' 05.1"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 73%.

The mask-weighted light curve shows a single peak with a FRED-like profile, 
starting at T+0 and lasting approximately five seconds. T90 (15-350 keV) is 3.09 
+- 0.50 sec (estimated error including systematics).

The time-averaged spectrum from T+0.26 to T+3.64 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.98 +- 0.21.  The fluence in the 15-150 keV band is 1.9 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.34 sec in the 15-150 keV band
is 1.2 +- 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/610501/BA/