Notes:

• 1) The fitting includes the systematic errors.
• 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
• 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.

Time averaged spectrum fit using the average DRM

Power-law model

Time interval is from   11.200 sec. to   27.200 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.2629     ( -0.323365   0.290953 )
Norm@50keV  : 1.26576E-03    ( -0.000291943   0.000286924 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.69 using 59 PHA bins.
# Reduced chi-squared =         0.7665 for     57 degrees of freedom 
# Null hypothesis probability =   9.024593e-01
 
Photon flux (15-150 keV)    in 16 sec: 0.216752 ( -0.030316  0.030339 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.92314e-07 ( -3.56962e-08  3.77299e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   11.200 sec. to   27.200 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.35236     ( -0.294517   1.8697 )
Epeak [keV] : 159.682      (   )
Norm@50keV  : 1.11275E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.69 using 59 PHA bins.
# Reduced chi-squared =         0.7802 for     56 degrees of freedom 
# Null hypothesis probability =   8.843664e-01
 
Photon flux (15-150 keV)    in 16 sec: 0.214598 ( -0.0302  0.030024 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.93344e-07 ( -3.62933e-08  3.89618e-08 ) ergs/cm2
 

1-s peak spectrum fit

1-s peak spectrum unavailable, likely because there are no event data in the 1-s peak range.

Time-resolved spectra