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 -22.168 sec. to 55.736 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.60138 ( -0.231438 0.227555 )
Norm@50keV : 1.25153E-03 ( -0.00016753 0.000166127 )
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#Fit statistic : Chi-Squared = 58.03 using 59 PHA bins.
# Reduced chi-squared = 1.018 for 57 degrees of freedom
# Null hypothesis probability = 4.370189e-01
Photon flux (15-150 keV) in 77.9 sec: 0.160901 ( -0.021601 0.021687 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.11757e-07 ( -1.29342e-07 1.30338e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -22.168 sec. to 55.736 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.46799 ( -0.35668 1.10762 )
Epeak [keV] : 198.845 ( -211.005 -211.005 )
Norm@50keV : 1.46101E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.98 using 59 PHA bins.
# Reduced chi-squared = 1.035 for 56 degrees of freedom
# Null hypothesis probability = 4.020508e-01
Photon flux (15-150 keV) in 77.9 sec: 0.160056 ( -0.022643 0.021888 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.04684e-07 ( -1.41889e-07 1.35637e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 25.920 sec. to 26.920 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.39822 ( -0.467908 0.500285 )
Norm@50keV : 4.68575E-03 ( -0.00142214 0.00142178 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.57 using 59 PHA bins.
# Reduced chi-squared = 1.045 for 57 degrees of freedom
# Null hypothesis probability = 3.821454e-01
Photon flux (15-150 keV) in 1 sec: 0.570452 ( -0.183055 0.185963 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.52971e-08 ( -1.419e-08 1.4335e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 25.920 sec. to 26.920 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.473787 ( -2.08562 4.44713 )
Epeak [keV] : 62.3472 ( -20.8534 -61.9194 )
Norm@50keV : 4.57408E-02 ( -0.0481469 16.3326 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.73 using 59 PHA bins.
# Reduced chi-squared = 1.031 for 56 degrees of freedom
# Null hypothesis probability = 4.112807e-01
Photon flux (15-150 keV) in 1 sec: 0.545938 ( -0.180798 0.187202 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.97887e-08 ( -1.48433e-08 1.61845e-08 ) ergs/cm2
Time-resolved spectra
