T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), M. De Pasquale (UCL-MSSL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110520A (trigger #453747)
(De Pasquale, et al., GCN Circ. 12020). The BAT ground-calculated position is
RA, Dec = 134.363, 56.418 deg which is
RA(J2000) = 08h 57m 27.1s
Dec(J2000) = +56d 25' 04.9"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 69%.
The mask-weighted light curve shows a single FRED peak starting at ~T-2 sec,
peaking at ~T+4 sec, and ending at ~T+40 sec. T90 (15-350 keV)
is 15.7 +- 1.8 sec (estimated error including systematics).
The time-averaged spectrum from T-1.2 to T+16.6 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.13 +- 0.10. The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+4.15 sec in the 15-150 keV band
is 1.1 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
The results of the batgrbproduct analysis are available at