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 -12.308 sec. to 137.268 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.53739 ( -0.0339927 0.0340034 )
Norm@50keV : 1.87345E-02 ( -0.000315896 0.000315879 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.29 using 59 PHA bins.
# Reduced chi-squared = 0.8297 for 57 degrees of freedom
# Null hypothesis probability = 8.168520e-01
Photon flux (15-150 keV) in 149.6 sec: 2.36317 ( -0.04685 0.04703 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.64364e-05 ( -4.58063e-07 4.58588e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -12.308 sec. to 137.268 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2953 ( -0.142079 0.146605 )
Epeak [keV] : 163.069 ( -40.657 143.061 )
Norm@50keV : 2.39739E-02 ( -0.00315892 0.00376402 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.73 using 59 PHA bins.
# Reduced chi-squared = 0.6916 for 56 degrees of freedom
# Null hypothesis probability = 9.619380e-01
Photon flux (15-150 keV) in 149.6 sec: 2.30953 ( -0.05523 0.0556 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.59484e-05 ( -5.38599e-07 5.3729e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 57.344 sec. to 58.344 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.13044 ( -0.0376752 0.037753 )
Norm@50keV : 0.181506 ( -0.00373229 0.00373014 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.31 using 59 PHA bins.
# Reduced chi-squared = 1.093 for 57 degrees of freedom
# Null hypothesis probability = 2.931317e-01
Photon flux (15-150 keV) in 1 sec: 21.1200 ( -0.4566 0.4573 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.87988e-06 ( -4.1099e-08 4.11317e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 57.344 sec. to 58.344 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.879393 ( -0.153318 0.158695 )
Epeak [keV] : 264.006 ( -78.7534 298.354 )
Norm@50keV : 0.232504 ( -0.0319048 0.0382511 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.37 using 59 PHA bins.
# Reduced chi-squared = 0.9709 for 56 degrees of freedom
# Null hypothesis probability = 5.367888e-01
Photon flux (15-150 keV) in 1 sec: 20.8096 ( -0.4898 0.4909 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.8578e-06 ( -4.36216e-08 4.35409e-08 ) ergs/cm2
Time-resolved spectra
