[vsnet-grb-info 1975] GRB050815: Refined analysis of the Swift-BAT burst

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3814
SUBJECT: GRB050815:  Refined analysis of the Swift-BAT burst
DATE:    05/08/15 22:13:37 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <Scott at lheamail.gsfc.nasa.gov>

D. Hullinger (GSFC/UMD), M. Ajello (MPE), L. Barbier (GSFC),
S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL),
R. Fink (GSFC), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC)
on behalf of the Swift-BAT team:

Using the full data set from the recent telemetry downlink, we report
further analysis of Swift-BAT GRB 050815 (trigger #150532)
(Fox, et al., GCN 3811).  The ground-analysis position is
RA,Dec 293.579,+9.145 (J2000) with an uncertainty of 2 arcmin
(radius, 90%, stat+sys).  This is 59 arcsec from the XRT
refined position (Morris et al., GCN 3812).  The light curve
shows an increase in emission starting at T-2 sec with a peak
at ~T+1 sec and the burst is over by T+4 sec.  T90 is 2.8 +/-1 sec.
Fitting a simple power law over the interval from T-0.7 to T+2.4 sec,
the photon index is 1.8 +/- 0.2 with a fluence of
1.5 +/- 0.4 x 10^-7 erg/cm^2 in the 15-350 keV band (90% c.l.).
The peak flux in a 1-sec wide window starting at T-0.1 seconds
is 0.66 +/- 0.14 ph/cm^2/sec (15-350 keV).  Based on the duration
of >2 sec and the soft spectrum, it does not appear that this burst
is in the short-hard category.