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GCN Circular 18634

Subject

Swift-BAT refined analysis of trigger 664624 from SGR J1819-1600

Date

2015-11-22T21:22:32Z (8 years ago)

From

Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), K. L. Page (U Leicester), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-120 to T+242 sec from the recent telemetry downlinks,
we report further analysis of an outburst from SGR J1819-1600  (trigger #664624)
(Page, et al., GCN Circ. 18632Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 274.714, -15.981 deg, which is 
   RA(J2000)  =  18h 18m 51.4s 
   Dec(J2000) = -15d 58' 52.6" 
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 86%.
 
The mask-weighted light curve shows a single spike starting at T_zero.
T90 (15-350 keV) is 0.032 +- 0.14 sec (estimated error including systematics).
 
The time-averaged spectrum from T+0.000 to T+0.032 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.93 +- 0.38.  The fluence in the 15-150 keV band is 1.5 +- 0.4 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.00 sec in the 15-150 keV band
is 4.8 +- 1.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/664624/BA/