GCN Circular 9406
Subject
GRB 090519, Swift-BAT refined analysis
Date
2009-05-20T02:30:23Z (15 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), C. B. Markwardt (GSFC/UMD),
D. M. Palmer (LANL), A. M. Parsons (GSFC), M. Perri (ASDC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-119 to T+276 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 090519 (trigger #352648)
(Perri, et al., GCN Circ. 9400). The BAT ground-calculated position is
RA, Dec = 142.317, 0.190 deg which is
RA(J2000) = 09h 29m 16.2s
Dec(J2000) = +00d 11' 23.9"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
This is 0.8 arcmin from the enhanced XRT afterglow position (Goad et al.
GCN Circ #9405). The partial coding was 57%.
The mask-weighted lightcurve shows multiple overlapping peaks starting
at about T-17 sec and ending about T+95 sec. T90 (15-350 keV) is
64 +- 10 sec (estimated error including systematics).
The time-averaged spectrum from T-12.4 to T+60.4 sec is best fit by a
simple power-law model. The power law index of the time-averaged
spectrum is 1.02 +- 0.20. The fluence in the 15-150 keV band is
1.2 +- 0.1 x 10-06 erg/cm2. The 1-sec peak photon flux measured from
T-10 sec in the 15-150 keV band is 0.6 +- 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/352648/BA/