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 -57.324 sec. to 400.776 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.64619 ( -0.0764155 0.0760207 )
Norm@50keV : 1.38642E-03 ( -5.70808e-05 5.68578e-05 )
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#Fit statistic : Chi-Squared = 70.85 using 59 PHA bins.
# Reduced chi-squared = 1.243 for 57 degrees of freedom
# Null hypothesis probability = 1.026738e-01
Photon flux (15-150 keV) in 458.1 sec: 0.180812 ( -0.007699 0.007728 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.9099e-06 ( -2.56885e-07 2.5804e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -57.324 sec. to 400.776 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.57136 ( -0.111465 0.295374 )
Epeak [keV] : 264.288 ( -421.204 -526.358 )
Norm@50keV : 1.50895E-03 ( -0.000112974 0.000535557 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.01 using 59 PHA bins.
# Reduced chi-squared = 1.268 for 56 degrees of freedom
# Null hypothesis probability = 8.533757e-02
Photon flux (15-150 keV) in 458.1 sec: 0.180369 ( -0.008321 0.008026 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.89185e-06 ( -2.88729e-07 2.71546e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -53.100 sec. to -52.100 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.868598 ( -0.115733 0.118438 )
Norm@50keV : 1.74229E-02 ( -0.00120151 0.00119565 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.10 using 59 PHA bins.
# Reduced chi-squared = 1.177 for 57 degrees of freedom
# Null hypothesis probability = 1.692336e-01
Photon flux (15-150 keV) in 1 sec: 1.99964 ( -0.1371 0.13729 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.97984e-07 ( -1.42075e-08 1.42574e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -53.100 sec. to -52.100 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.474669 ( -0.435403 0.539604 )
Epeak [keV] : 229.443 ( -99.2942 -229.46 )
Norm@50keV : 2.58043E-02 ( -0.00896663 0.0174982 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.17 using 59 PHA bins.
# Reduced chi-squared = 1.164 for 56 degrees of freedom
# Null hypothesis probability = 1.880417e-01
Photon flux (15-150 keV) in 1 sec: 1.97299 ( -0.14108 0.14107 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.95016e-07 ( -1.50087e-08 1.48828e-08 ) ergs/cm2
Time-resolved spectra
