[vsnet-grb-info 22507] GRB 190519A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24606
SUBJECT: GRB 190519A: Swift-BAT refined analysis
DATE:    19/05/19 22:10:22 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien at nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
C. B. Markwardt (GSFC), 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 190519A (trigger #904394)
(Ukwatta et al., GCN Circ. 24595).  The BAT ground-calculated position is
RA, Dec = 114.758, -38.813 deg which is
   RA(J2000)  =  07h 39m 01.9s
   Dec(J2000) = -38d 48' 46.6"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 8%.

The mask-weighted light curve shows a multi-peaked structure that starts at
~T-60 s and ends at ~T+15 s. The main peak occurs at ~T0. T90 (15-350 keV)
is 45.58 +- 2.86 sec (estimated error including systematics).

The time-averaged spectrum from T-56.97 to T+14.79 sec is best fit by a
power law
with an exponential cutoff.  This fit gives a photon index 1.32 +- 0.24,
and Epeak of 90.0 +- 35.0 keV (chi squared 76.36 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.8 +- 0.1 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T-0.21 sec in the 15-150 keV band is
20.6 +- 1.7 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.72 +- 0.06 (chi squared 85.04 for 57 d.o.f.).  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/904394/BA/