GCN Circular 5141
Subject
GRB 060515 BAT refined analysis
Event
Date
2006-05-15T17:24:44Z (20 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
E. Fenimore (LANL), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/JSPS/USRA),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
Using the data set from T-239 to T+360 sec from recent telemetry
downlinks, we report further analysis of BAT GRB 060515
(trigger #210084) (Cummings, et al., GCN 5132). The BAT ground-
calculated position is
(RA,Dec) = 127.295, 73.562 deg {8h 29m 10.7s, 73d 33' 43.2"} (J2000)
+- 1.5 arcmin, (radius, sys+stat, 90% containment). This position
is 0.7 arcmin from the onboard-calculated position and 0.3 arcmin
from the XRT refined position (Page et al. GCN 5139). The partial
coding was 38%.
The light curve shows a single weak, long FRED peak. T90 (15-350 keV)
is 52 +- 8 sec (estimated error including systematics). There is no
indication of emission in the BAT energy band after T+70. As noted
earlier, Swift did not slew to the burst because of an Earth limb
constraint. At T+140 sec, Swift executed a preplanned slew away from
the burst, which was then in the extreme partially coded field of view,
so constraints on emission are poor. After T+360, Swift entered the
SAA and we have no further information on any possible extended
emission.
The time-averaged spectrum from T+0.2 to T+57.5 is best fit by
a simple power-law model. The power-law index of the time-averaged
spectrum is 1.15 +- 0.15. The fluence in the 15-150 keV band is
1.4 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured
from T+5.58 sec in the 15-150 keV band is 0.8 +- 0.2 ph/cm2/sec. All
the quoted errors are at the 90% confidence level.