TITLE:   GCN CIRCULAR
NUMBER:  8415
SUBJECT: GRB 081025 BAT refined analysis
DATE:    08/10/26 19:12:08 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc@milkyway.gsfc.nasa.gov>

J. R. Cummings (GSFC/UMBC), A. Copete (Harvard), J. Grindlay (Harvard),
S. D. Barthelmy (GSFC), N. Gehrels (GSFC), C. Guidorzi (INAF-OAB) 

Using the data set from T+9 to T+129 sec (T0 is here defined as the
beginning of the Swift slew manuever), we report further analysis of
BATSS GRB 081025 (Copete, et al., GCN Circ. 8409). 

Using the the previously reported position, the partial coding averaged 
over the event was 70%.  This is 2.1 arcmin from the XRT afterglow 
candidate (Mao et al. GCN Circ. 8411).

The mask-weighted lightcurve features a main peak starting at T+63 sec
lasting 12 sec, followed in succession by 3 peaks, a 1.4 sec long peak
at T+77 sec, a 4.2 sec long peak at T+83sec, and a 2.2 sec long peak at
T+88sec.  T90 (15-350 keV) is 23 +- 2 sec (estimated error including
systematics).

The time-averaged spectrum from T+63 to T+89 sec is best fit by a
simple power-law model.  The power law index of the time-averaged
spectrum is 1.12 +- 0.05.  The fluence in the 15-150 keV band is
(1.9 +- 0.2) x 10-06 erg/cm2.  The 1-sec peak photon flux measured from
T+68 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec.  All the
quoted errors are at the 90% confidence level.

The results of the analysis will be available (in a few days) at
http://gcn.gsfc.nasa.gov/notices_s/BATS0021/BA/