[vsnet-grb-info 14648] GRB 140311A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15962
SUBJECT: GRB 140311A: Swift-BAT refined analysis
DATE:    14/03/12 12:37:56 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.krimm at nasa.gov>

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

Using the data set from T-239 to T+423 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 140311A (trigger #591390)
(Racusin, et al., GCN Circ. 15944).  The BAT ground-calculated position is
RA, Dec = 209.293, 0.607 deg which is
    RA(J2000)  =  13h 57m 10.4s
    Dec(J2000) = +00d 36' 23.9"
with an uncertainty of 3.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 10%.

The mask-weighted light curve shows two weak peaks, the first from roughly T-5 
sec to T+5 sec and the second from approximately T+40 to T+60 sec. T90 (15-350 
keV) is 71.4 +- 9.5 sec (estimated error including systematics).

The time-averaged spectrum from -4.456 to 83.736 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.67 +- 0.23.  The fluence in the 15-150 keV band is 2.3 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-2.40 sec in the 15-150 keV band
is 1.3 +- 0.5 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/591390/BA/