[vsnet-grb-info 20796] GRB 180704A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22894
SUBJECT: GRB 180704A: Swift-BAT refined analysis
DATE:    18/07/04 13:36:38 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at milkyway.gsfc.nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), E. Sonbas (Adiyaman Univ.), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+760 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 180704A (trigger #846088)
Sonbas, et al., GCN Circ. 22885).  The BAT ground-calculated position is
RA, Dec = 32.605, 69.965 deg, which is 
   RA(J2000)  =  02h 10m 25.1s 
   Dec(J2000) = +69d 57' 54.9" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 7%.
 
The mask-weighted light curve shows several peaks, the first starting at ~T-21 sec,
and the lagest peak at ~T+1 sec, with a long tail out to ~T+40 sec.
T90 (15-350 keV) is 19.7 +- 1.4 sec (estimated error including systematics).
 
The time-averaged spectrum from T-17.90 to T+4.24 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.22 +- 0.10.  The fluence in the 15-150 keV band is 6.2 +- 0.4 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.04 sec in the 15-150 keV band
is 9.6 +- 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/846088/BA/