[vsnet-grb-info 5044] GRB 070810B, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6753
SUBJECT: GRB 070810B, Swift-BAT refined analysis
DATE:    07/08/11 00:19:40 GMT
FROM:    Craig Markwardt at NASA/GSFC/UMD  <craigm at milkyway.gsfc.nasa.gov>

T. Sakamoto (GSFC/ORAU), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), F. E. Marshall (GSFC),
D. Palmer (LANL), A. Parsons (GSFC), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+303 sec from recent telemetry
downlinks, we report further analysis of BAT GRB 070810B (trigger
#287409) (Marshall, et al., GCN Circ. 6743).  The BAT ground-calculated
position is RA, Dec = 8.952, 8.822 deg which is
    RA(J2000) = 0h 35m 48.4s
    Dec(J2000) = 8d 49' 18"
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The light curve is a single FRED-like peak starting at T+0, and ending
at T+0.12 sec.  T90 (15-350 keV) is 80 +- 10 msec (estimated error 
including systematics).

The time-averaged spectrum from T+0.008 to T+0.092 sec is best fit by a
simple power-law model.  The power law index of the time-averaged
spectrum is 1.44 +- 0.37.  The fluence in the 15-150 keV band is
1.2 +- 0.3 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from 
T-0.45 sec in the 15-150 keV band is 1.8 +- 0.4 ph/cm2/sec.  All the 
quoted errors are at the 90% confidence level.