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    1.600 sec. to    6.400 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.18563     ( -0.275136   0.278789 )
Norm@50keV  : 1.08655E-02    ( -0.00173135   0.00173131 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.91 using 59 PHA bins.
# Reduced chi-squared =         0.8231 for     57 degrees of freedom 
# Null hypothesis probability =   8.272782e-01
 
Photon flux (15-150 keV)    in 4.8 sec: 1.27287 ( -0.20749  0.20798 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.31365e-07 ( -9.41333e-08  9.51067e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    1.600 sec. to    6.400 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.685525     ( -0.644489   1.51216 )
Epeak [keV] : 142.328      ( -142.323 -142.323 )
Norm@50keV  : 1.87304E-02    ( -0.00935111   0.0745978 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.39 using 59 PHA bins.
# Reduced chi-squared =         0.8285 for     56 degrees of freedom 
# Null hypothesis probability =   8.163176e-01
 
Photon flux (15-150 keV)    in 4.8 sec: 1.24814 ( -0.21765  0.21595 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.16096e-07 ( -1.04396e-07  1.01851e-07 ) 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