TITLE:   GCN CIRCULAR
NUMBER:  24564
SUBJECT: GRB 190515B: Swift-BAT refined analysis
DATE:    19/05/16 13:28:03 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

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

Using the data set from T-239 to T+963 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 190515B (trigger #903845)
(Moss et al., GCN Circ. 24553).  The BAT ground-calculated position is
RA, Dec = 98.826, 52.322 deg which is
   RA(J2000)  =  06h 35m 18.3s
   Dec(J2000) = +52d 19' 17.6"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 67%.

The mask-weighted light curve shows a single-pulse structure that starts at
~T-30 s, peaks at ~T0, and ends at ~T+30 s. T90 (15-350 keV) is 46.4 +-
12.3 sec
(estimated error including systematics).

The time-averaged spectrum from T-30.84 to T+31.02 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.74 +- 0.15.  The fluence in the 15-150 keV band is 1.6 +- 0.1 x 10^-6
erg/cm2.
The 1-sec peak photon flux measured from T-0.39 sec in the 15-150 keV band
is 1.1 +- 0.2 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/903845/BA/