TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4891
SUBJECT: GRB 060319: Swift-BAT refined analysis
DATE:    06/03/19 05:26:40 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori@milkyway.gsfc.nasa.gov>

T. Sakamoto (GSFC/ORAU), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger ((BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), G. Sato (ISAS), J. Tueller (GSFC)

Using the data set from T-299 to T+303 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 060319 (trigger #202035)
(Ziaeepour, et al., GCN 4885).  The BAT ground-calculated is RA,Dec =
176.366, 60.041 deg {11h 45m 27.7s, 60d 2' 29.3"} (J2000) +- 2.3 arcmin,
(radius, sys+stat, 90% containment).  The partial coding was 100%.

The mask-weighted light curve shows two peaks.  The first and second
spikes peak around T+4 sec and T+12 sec respectively.  Due to the pre-plan
target observation, GRB 060319 was outside of the BAT FOV before T-60 sec.
Thus, we do not know any activity about GRB 060319 before T-60 sec.  
T90 (15-350 keV) is 12.0 +- 1 sec (estimated error including systematics).

The time-averaged spectrum from T+1.0 to T+18.0 is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.35 +- 0.27.  The fluence in the 15-150 keV band is
2.7 +- 0.4 x 10^-07 erg/cm2.  The 1-sec peak photon flux measured
from T+4.00 sec in the 15-150 keV band is 1.1 +- 0.1 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.