[vsnet-grb-info 23931] GRB 191017B: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26030
SUBJECT: GRB 191017B: Swift-BAT refined analysis
DATE:    19/10/18 23:37:15 GMT
FROM:    Sibasish Laha at GSFC  <sibasish.laha at nasa.gov>

J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), B. Sbarufatti (PSU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL),
S. D. Barthelmy (GSFC), (i.e. the Swift-BAT team):

Using the data set from T-82 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 191017B (trigger #929981)
(Sbarufatti et al., GCN Circ. 26021).  The BAT ground-calculated position is
RA, Dec = 245.131, -73.583 deg which is
   RA(J2000)  =  16h 20m 31.3s
   Dec(J2000) = -73d 34' 57.7"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 44%.

The mask weighted light curve shows a single peak structure with a duration of ~8 sec.
The overall structure starts at ~ T-2 sec and lasts till ~ T+6 sec.
T90 (15-350 keV) is 5.95 +- 1.28 sec (estimated error including systematics).

The time-averaged spectrum from T-1.34 to T+5.59 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.82 +- 0.20.  The fluence in the 15-150 keV band is 5.6 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.36 sec in the 15-150 keV band
is 1.9 +- 0.3 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/929981/BA/