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 -0.196 sec. to 120.176 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.55681 ( -0.164956 0.164168 )
Norm@50keV : 2.35195E-03 ( -0.000216091 0.000215592 )
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#Fit statistic : Chi-Squared = 46.55 using 59 PHA bins.
# Reduced chi-squared = 0.8167 for 57 degrees of freedom
# Null hypothesis probability = 8.370117e-01
Photon flux (15-150 keV) in 120.4 sec: 0.298341 ( -0.028845 0.029007 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.66365e-06 ( -2.59579e-07 2.61157e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.196 sec. to 120.176 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.55443 ( -1.05694 0.581167 )
Epeak [keV] : 9981.81 ( -9978.78 -9978.78 )
Norm@50keV : 2.35830E-03 ( -0.00147435 0.00251309 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.55 using 59 PHA bins.
# Reduced chi-squared = 0.8312 for 56 degrees of freedom
# Null hypothesis probability = 8.118712e-01
Photon flux (15-150 keV) in 120.4 sec: 0.297755 ( -0.030136 0.029443 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.65795e-06 ( -2.76199e-07 2.64764e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.004 sec. to 1.004 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.35842 ( -0.124748 0.124817 )
Norm@50keV : 9.04534E-02 ( -0.00710032 0.00710019 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.81 using 59 PHA bins.
# Reduced chi-squared = 1.084 for 57 degrees of freedom
# Null hypothesis probability = 3.083586e-01
Photon flux (15-150 keV) in 1 sec: 10.9163 ( -0.9055 0.9075 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.81881e-07 ( -7.2841e-08 7.30676e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.004 sec. to 1.004 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.529779 ( -0.560671 0.645502 )
Epeak [keV] : 100.377 ( -21.8836 88.1868 )
Norm@50keV : 0.216936 ( -0.09521 0.200754 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.12 using 59 PHA bins.
# Reduced chi-squared = 0.9843 for 56 degrees of freedom
# Null hypothesis probability = 5.080341e-01
Photon flux (15-150 keV) in 1 sec: 10.6416 ( -0.9238 0.9271 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.67022e-07 ( -7.53596e-08 7.51713e-08 ) ergs/cm2
Time-resolved spectra
