[vsnet-grb-info 3318] GRB 060522: Swift-BAT Refined Analysis

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5153
SUBJECT: GRB 060522: Swift-BAT Refined Analysis
DATE:    06/05/22 13:25:26 GMT
FROM:    Hans Krimm at NASA-GSFC  <krimm at milkyway.gsfc.nasa.gov>

H. Krimm (GSFC/USRA), L. Barbier (GSFC),  S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), 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-239.0 to T+730.1 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060522 (trigger #211117)
(Fox, et al., GCN 5150).  The BAT ground-calculated position
is (RA,Dec) = 322.953, 2.889 deg {21h 31m 48.8s, 2d 53' 18.9"} (J2000)
+- 1.5 arcmin, (radius, sys+stat, 90% containment).  The partial 
coding was 75%.

The mask-weighted light curve shows two broad peaks, the first with a FRED-like
profile from T+0 to T+20 sec and the second with a square profile from T+25 to
T+80 sec. Nearly all emission is below 100 keV.  T90 (15-350 keV) is
69 +- 5 sec (estimated error including systematics).

The time-averaged spectrum from T+0.2 to T+76.9 is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 1.59 +- 0.15.  The fluence in the 15-150 keV band is
1.1 +- 0.1 x 10^-06 erg/cm2.  The 1-sec peak photon flux measured from
T+4.41 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.