[vsnet-grb-info 3307] GRB 060505 BAT refined analysis

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5142
SUBJECT: GRB 060505 BAT refined analysis
DATE:    06/05/15 19:54:31 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc at milkyway.gsfc.nasa.gov>

D. Hullinger (BYU-Idaho), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
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-2 to T+8 sec, we report further analysis 
of GRB 060505 (Palmer et al. GCN 5076).  The refined ground-analysis
position is RA, Dec 331.776d, -27.825d (22h 07m 06.3s, -27d 49' 31")
+- 2.1 arcmin (J2000, estimated uncertainty, 90% containment).  This 
position is 0.6 arcmin from the XRT refined position reported by 
Conciatore et al. in GCN 5081. The partial coding was 11%.  As noted 
earlier, this was a ground-discovered burst that did not trigger the 
BAT instrument.  Thus we have only a limited set of full-resolution 
data.

The mask-weighted light curve shows a single rounded peak. T90 is
4 +- 1 sec (15-350 keV, estimated error including systematics).
The BAT counting rates give no indication of extended emission.
However, Swift was approaching the SAA and BAT entered SAA mode 
with even more limited data collection at T+60, so constraints on 
emission are poor.

The time-averaged spectrum is well fit by a simple powerlaw with
index 1.3 +- 0.3.  The energy fluence in the 15-150 keV band is
6.2 +- 1.1 x 10^-7 ergs/cm2.  The 1-second peak flux, also in the
15-150 keV band, from T+2 sec is 1.9 +- 0.3 ph/cm2/s.  All the 
quoted errors are at the 90% confidence level.