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GCN Circular 16799

Subject

GRB 140907A: Swift-BAT refined analysis

Date

2014-09-08T16:12:53Z (10 years ago)

From

Hans Krimm at NASA-GSFC <hans.a.krimm@nasa.gov>

T. Sakamoto (AGU), 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 (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL)
(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 140907A (trigger #611933)
(Krimm, et al., GCN Circ. 16788Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 48.133, 46.596 deg which is
    RA(J2000)  =  03h 12m 31.9s
    Dec(J2000) = +46d 35' 43.8"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 65%.

The mask-weighted light curve shows a single peak with superimposed spikes,
running from approximately T-10 to T+40 sec.  T90 (15-350 keV) is 79.2 +- 31.4 sec
(estimated error including systematics).

The time-averaged spectrum from T-91.2 to T+39.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.72 +- 0.07.  The fluence in the 15-150 keV band is 4.3 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+17.47 sec in the 15-150 keV band
is 2.5 +- 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/611933/BA/