[vsnet-grb-info 1989] GRB 050819 Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3828
SUBJECT: GRB 050819 Swift-BAT refined analysis
DATE:    05/08/19 20:09:55 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc at milkyway.gsfc.nasa.gov>

S. Barthelmy (GSFC), L. Barbier (GSFC), J. Cummings (GSFC/NRC),
D. Hullinger (GSFC/UMD), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), F. Marshall (GSFC),
A. Smale (NASA HQ), 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 050819 (trigger #151131)
(De Pasquale, et al., GCN 3826).  The ground-analysis position is
RA,Dec 358.757, +24.874 (J2000) with an uncertainty of 2 arcmin
(radius, 90%, stat+sys).  This is 50 arcseconds from the XRT ground-
calculated position reported by Kennea et al. in GCN Circ. 3827.

The light curve shows a long weak peak with indistinct structure from
T-12 to T+37 seconds.  T90 is 36 +/- 4 sec.  Fitting a simple power
law over the interval from T-2 to T+34 sec, the photon index is
2.6 +/- 0.3 with a fluence of 4.2 +/- 0.8 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+9.5 seconds is 0.46 +/- 0.14 ph/cm^2/sec (15-350 keV).