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 0.000 sec. to 6.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.84986 ( -0.123439 0.120215 )
Norm@50keV : 1.00890E-02 ( -0.000785817 0.000777339 )
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#Fit statistic : Chi-Squared = 70.22 using 59 PHA bins.
# Reduced chi-squared = 1.232 for 57 degrees of freedom
# Null hypothesis probability = 1.121428e-01
Photon flux (15-150 keV) in 6 sec: 1.41811 ( -0.09845 0.09854 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.56687e-07 ( -4.32926e-08 4.37274e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 6.000 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.906274 ( -0.558105 0.637727 )
Epeak [keV] : 52.4560 ( -7.59228 15.2635 )
Norm@50keV : 3.28081E-02 ( -0.0162399 0.0393633 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.22 using 59 PHA bins.
# Reduced chi-squared = 1.093 for 56 degrees of freedom
# Null hypothesis probability = 2.940555e-01
Photon flux (15-150 keV) in 6 sec: 1.36237 ( -0.10351 0.10354 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.16263e-07 ( -4.72327e-08 4.86492e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.000 sec. to 2.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.5455 ( -0.160389 0.156945 )
Norm@50keV : 2.06085E-02 ( -0.00215557 0.00214293 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 78.38 using 59 PHA bins.
# Reduced chi-squared = 1.375 for 57 degrees of freedom
# Null hypothesis probability = 3.170541e-02
Photon flux (15-150 keV) in 1 sec: 2.60562 ( -0.26338 0.26358 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.94156e-07 ( -2.18144e-08 2.20013e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.000 sec. to 2.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.147475 ( -0.857899 1.05794 )
Epeak [keV] : 61.9806 ( -8.49951 16.915 )
Norm@50keV : 0.152028 ( -0.0955367 0.357968 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.02 using 59 PHA bins.
# Reduced chi-squared = 1.161 for 56 degrees of freedom
# Null hypothesis probability = 1.915238e-01
Photon flux (15-150 keV) in 1 sec: 2.47524 ( -0.273 0.27252 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.76986e-07 ( -2.2311e-08 2.32167e-08 ) ergs/cm2
Time-resolved spectra
