[vsnet-grb-info 15984] GRB 150101A Swift-BAT refined analysis of the short hard burst

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17266
SUBJECT: GRB 150101A Swift-BAT refined analysis of the short hard burst
DATE:    15/01/02 21:19:17 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings at nasa.gov>

W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC),  J. R. Cummings,
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
  
Using the data set from T-240 to T+962 sec, we report further analysis
of BAT GRB 150101A (trigger #623158) (Vargas, et al., GCN Circ. 17261).
The BAT ground-calculated position is RA, Dec = 312.599, 36.669 deg which is
    RA(J2000)  =  20h 50m 23.6s
    Dec(J2000) = +36d 40' 07.8"
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 91%.
  
The mask-weighted light curve shows a single peak.  T90 (15-350 keV) is
0.060 +- 0.005 sec (estimated error including systematics).
  
The time-averaged spectrum from T+0.0 to T+0.68 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.26 +- 0.31.  The fluence in the 15-150 keV band is
(2.3 +- 0.5) x 10^-08 erg/cm2.  The 1-sec peak photon flux measured from
T-0.46 sec in the 15-150 keV band is 0.3 +- 0.1 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/623158/BA/