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 -4.824 sec. to 23.400 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31763 ( -0.127183 0.127937 )
Norm@50keV : 2.33302E-02 ( -0.0018084 0.00180763 )
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#Fit statistic : Chi-Squared = 48.41 using 59 PHA bins.
# Reduced chi-squared = 0.8492 for 57 degrees of freedom
# Null hypothesis probability = 7.840672e-01
Photon flux (15-150 keV) in 28.22 sec: 2.79262 ( -0.22997 0.23064 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.47928e-06 ( -5.27638e-07 5.29246e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.824 sec. to 23.400 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.772011 ( -0.491766 0.553302 )
Epeak [keV] : 128.938 ( -38.6826 484.452 )
Norm@50keV : 4.11529E-02 ( -0.0161518 0.0302104 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.77 using 59 PHA bins.
# Reduced chi-squared = 0.7994 for 56 degrees of freedom
# Null hypothesis probability = 8.594822e-01
Photon flux (15-150 keV) in 28.22 sec: 2.73545 ( -0.23542 0.23606 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.38847e-06 ( -5.42228e-07 5.4159e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.692 sec. to 5.692 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.24425 ( -0.281102 0.285079 )
Norm@50keV : 6.92935E-02 ( -0.0125287 0.0125061 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.92 using 59 PHA bins.
# Reduced chi-squared = 0.8934 for 57 degrees of freedom
# Null hypothesis probability = 7.011137e-01
Photon flux (15-150 keV) in 1 sec: 0.261640 ( -0.047906 0.263884 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.94624e-07 ( -1.37528e-07 1.38577e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.692 sec. to 5.692 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.110338 ( -1.24795 2.01023 )
Epeak [keV] : 84.8590 ( -26.87 -84.8435 )
Norm@50keV : 0.258821 ( -0.25897 2.17955 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.10 using 59 PHA bins.
# Reduced chi-squared = 0.8767 for 56 degrees of freedom
# Null hypothesis probability = 7.315538e-01
Photon flux (15-150 keV) in 1 sec: 8.03356 ( -1.53841 1.52778 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.54953e-07 ( -1.48441e-07 1.50221e-07 ) ergs/cm2
Time-resolved spectra
