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 -0.096 sec. to 37.456 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.48341 ( -0.144997 0.144281 )
Norm@50keV : 2.55402E-03 ( -0.000199761 0.000198868 )
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#Fit statistic : Chi-Squared = 60.32 using 59 PHA bins.
# Reduced chi-squared = 1.058 for 57 degrees of freedom
# Null hypothesis probability = 3.566235e-01
Photon flux (15-150 keV) in 37.55 sec: 0.317449 ( -0.024929 0.025018 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.12431e-07 ( -7.88268e-08 7.95876e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.096 sec. to 37.456 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.30536 ( -0.146767 0.33296 )
Epeak [keV] : 108.424 ( -9999.36 -9999.36 )
Norm@50keV : 9.70436E-04 ( -0.000413545 0.000456037 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.55 using 59 PHA bins.
# Reduced chi-squared = 1.046 for 56 degrees of freedom
# Null hypothesis probability = 3.820580e-01
Photon flux (15-150 keV) in 37.55 sec: 0.319304 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 9.17594e-07 ( -1.05194e-07 9.54303e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.132 sec. to 3.132 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.10355 ( -0.233593 0.239105 )
Norm@50keV : 1.06788E-02 ( -0.00138525 0.00138337 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.89 using 59 PHA bins.
# Reduced chi-squared = 0.9455 for 57 degrees of freedom
# Null hypothesis probability = 5.923465e-01
Photon flux (15-150 keV) in 1 sec: 1.23909 ( -0.16543 0.16603 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.11535e-07 ( -1.59301e-08 1.6056e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.132 sec. to 3.132 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.39412 ( -0.332973 0.843874 )
Epeak [keV] : 128.609 ( -9996.4 -9996.4 )
Norm@50keV : 1.71947E-03 ( -0.00171891 0.00192211 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.77 using 59 PHA bins.
# Reduced chi-squared = 0.9602 for 56 degrees of freedom
# Null hypothesis probability = 5.597694e-01
Photon flux (15-150 keV) in 1 sec: 1.23917 ( -0.17383 0.16506 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.11383e-07 ( -1.66176e-08 1.52742e-08 ) ergs/cm2
Time-resolved spectra
