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 -3.204 sec. to 244.552 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.45168 ( -0.0418236 0.0418457 )
Norm@50keV : 3.73282E-03 ( -7.90179e-05 7.90097e-05 )
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#Fit statistic : Chi-Squared = 32.63 using 59 PHA bins.
# Reduced chi-squared = 0.5724 for 57 degrees of freedom
# Null hypothesis probability = 9.960942e-01
Photon flux (15-150 keV) in 247.8 sec: 0.460221 ( -0.01106 0.011099 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.84995e-06 ( -1.95866e-07 1.95936e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.204 sec. to 244.552 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.33082 ( -0.139869 0.170383 )
Epeak [keV] : 312.961 ( -188.906 -312.963 )
Norm@50keV : 4.22174E-03 ( -0.000529202 0.000776823 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 31.07 using 59 PHA bins.
# Reduced chi-squared = 0.5549 for 56 degrees of freedom
# Null hypothesis probability = 9.972212e-01
Photon flux (15-150 keV) in 247.8 sec: 0.455483 ( -0.012661 0.012726 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.77529e-06 ( -2.20463e-07 2.19711e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.208 sec. to 5.208 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.604906 ( -0.103324 0.10652 )
Norm@50keV : 2.17867E-02 ( -0.001473 0.001458 )
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#Fit statistic : Chi-Squared = 59.71 using 59 PHA bins.
# Reduced chi-squared = 1.048 for 57 degrees of freedom
# Null hypothesis probability = 3.773050e-01
Photon flux (15-150 keV) in 1 sec: 2.54218 ( -0.15843 0.15874 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.77978e-07 ( -1.72966e-08 1.73401e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.208 sec. to 5.208 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.407887 ( -0.502456 0.57565 )
Epeak [keV] : 155.903 ( -32.9671 84.9223 )
Norm@50keV : 5.30566E-02 ( -0.0184319 0.0318866 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.37 using 59 PHA bins.
# Reduced chi-squared = 0.8280 for 56 degrees of freedom
# Null hypothesis probability = 8.170399e-01
Photon flux (15-150 keV) in 1 sec: 2.47432 ( -0.16112 0.16171 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.74025e-07 ( -1.81075e-08 1.80202e-08 ) ergs/cm2
Time-resolved spectra
