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 3.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.87978 ( -0.359018 0.325184 )
Norm@50keV : 1.40086E-02 ( -0.00321762 0.0030897 )
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#Fit statistic : Chi-Squared = 50.90 using 59 PHA bins.
# Reduced chi-squared = 0.8929 for 57 degrees of freedom
# Null hypothesis probability = 7.020647e-01
Photon flux (15-150 keV) in 3 sec: 1.99347 ( -0.36893 0.36902 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.86403e-07 ( -8.52264e-08 8.78076e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 3.000 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.21334 ( -1.11983 1.90157 )
Epeak [keV] : 51.6830 ( )
Norm@50keV : 3.31498E-02 ( )
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#Fit statistic : Chi-Squared = 50.23 using 59 PHA bins.
# Reduced chi-squared = 0.8969 for 56 degrees of freedom
# Null hypothesis probability = 6.920420e-01
Photon flux (15-150 keV) in 3 sec: 1.94970 ( -0.38067 0.37954 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) 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: -1.85713 ( -0.440105 0.393422 )
Norm@50keV : 1.74642E-02 ( -0.00531059 0.0051275 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.05 using 59 PHA bins.
# Reduced chi-squared = 0.8956 for 57 degrees of freedom
# Null hypothesis probability = 6.966788e-01
Photon flux (15-150 keV) in 1 sec: 2.46204 ( -0.62822 0.62836 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.60613e-07 ( -4.72399e-08 4.88175e-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: -0.115069 ( -1.83054 3.07704 )
Epeak [keV] : 46.2603 ( -12.7758 -46.2596 )
Norm@50keV : 0.173521 ( -0.173571 11.4927 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.48 using 59 PHA bins.
# Reduced chi-squared = 0.8657 for 56 degrees of freedom
# Null hypothesis probability = 7.521948e-01
Photon flux (15-150 keV) in 1 sec: 2.41205 ( -0.62632 0.62871 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.45724e-07 ( -4.58529e-08 4.99576e-08 ) ergs/cm2
Time-resolved spectra
