[vsnet-grb-info 14759] GRB 140402A BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16073
SUBJECT: GRB 140402A BAT refined analysis
DATE:    14/04/03 01:53:53 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings at nasa.gov>

J. R. Cummings on behalf of the BAT team

Based on 10 seconds of photon event data, we present refined analysis of
the BAT data on GRB 140402A (Bissaldi et al. GCN Circ #16069, Cummings
et al. GCN Circ #16071).

The best BAT location is RA, Dec 207.592, +5.971, which is:

RA(J2000) 13h 50m 22.2s
Dec(J2000) 05d 58' 16"

with an estimated 90% confidence radius of 2.8 arcmin.  This is 4 arcmin
from the previously reported BAT position based on the immediately
transmitted data (4 arcmin estimated 90% error), and 9.5 arcmin from the
Fermi-LAT position (12 arcmin estimated statistical 90% error).

The mask-weighted lightcurve shows a single nearly square pulse. T90
was about 0.031 +/- 0.003 seconds (estimated 90% confidence).

A powerlaw fit to the spectrum from 15 to 150 keV has a photon index of
0.89 +/- 0.44 (90% confidence). In 0.034 seconds the fluence was
(3.8 +/- 1.2) x 10^-8 ergs/cm^2 (62% confidence).