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 -0.548 sec. to 18.256 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.13695 ( -0.130455 0.12535 )
Norm@50keV : 7.12773E-03 ( -0.000625011 0.000616886 )
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#Fit statistic : Chi-Squared 68.28 using 59 bins.
Reduced chi-squared = 1.19789
# Null hypothesis probability of 1.46e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 18.8 sec: 1.14237 ( -0.07859 0.07865 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25008e-06 ( -9.79328e-08 9.91561e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.548 sec. to 18.256 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.15898 ( -0.533713 0.613502 )
Epeak [keV] : 35.6756 ( -10.0503 6.8226 )
Norm@50keV : 2.61070E-02 ( -0.0130798 0.0330975 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.37 using 59 bins.
Reduced chi-squared = 1.02446
# Null hypothesis probability of 4.24e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 18.8 sec: 1.10117 ( -0.08097 0.08115 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.15361e-06 ( -1.04239e-07 1.07952e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.476 sec. to 3.476 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.09386 ( -0.142883 0.136789 )
Norm@50keV : 3.08836E-02 ( -0.00323091 0.00319175 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 78.40 using 59 bins.
Reduced chi-squared = 1.37544
# Null hypothesis probability of 3.16e-02 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 4.84461 ( -0.41566 0.4158 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.86807e-07 ( -2.76458e-08 2.79533e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.476 sec. to 3.476 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.0412222 ( -0.785074 0.942641 )
Epeak [keV] : 39.4036 ( -4.13515 4.4791 )
Norm@50keV : 0.538059 ( -0.539948 1.40583 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 50.45 using 59 bins.
Reduced chi-squared = 0.900893
# Null hypothesis probability of 6.84e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 4.67404 ( -0.41718 0.41801 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.58607e-07 ( -2.63601e-08 2.75537e-08 ) ergs/cm2
Time-resolved spectra
