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 -0.016 sec. to 0.100 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.13516 ( -0.219633 0.220442 )
Norm@50keV : 3.53978E-02 ( -0.00459462 0.00458888 )
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#Fit statistic : Chi-Squared = 60.26 using 59 PHA bins.
# Reduced chi-squared = 1.057 for 57 degrees of freedom
# Null hypothesis probability = 3.588421e-01
Photon flux (15-150 keV) in 0.116 sec: 4.12103 ( -0.53778 0.53805 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.24656e-08 ( -6.31316e-09 6.36451e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.016 sec. to 0.100 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.937747 ( -0.553148 0.922177 )
Epeak [keV] : 297.134 ( -297.119 -297.119 )
Norm@50keV : 4.38772E-02 ( -0.0192453 0.0699647 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.08 using 59 PHA bins.
# Reduced chi-squared = 1.073 for 56 degrees of freedom
# Null hypothesis probability = 3.302399e-01
Photon flux (15-150 keV) in 0.116 sec: 1.63711 ( -0.5448 0.3203 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.21248e-08 ( -6.55039e-09 6.49776e-09 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.456 sec. to 0.544 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29364 ( -0.392605 0.395609 )
Norm@50keV : 4.92009E-03 ( -0.00109806 0.00109045 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.90 using 59 PHA bins.
# Reduced chi-squared = 1.016 for 57 degrees of freedom
# Null hypothesis probability = 4.418647e-01
Photon flux (15-150 keV) in 1 sec: 0.586304 ( -0.129934 0.130106 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.87012e-08 ( -1.22728e-08 1.25169e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.456 sec. to 0.544 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29004 ( -2.59393 1.54684 )
Epeak [keV] : 9998.02 ( -9998.29 -9998.29 )
Norm@50keV : 4.94105E-03 ( -0.0010957 0.0258074 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.90 using 59 PHA bins.
# Reduced chi-squared = 1.034 for 56 degrees of freedom
# Null hypothesis probability = 4.049926e-01
Photon flux (15-150 keV) in 1 sec: 0.587162 ( -0.133835 0.130161 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.8745e-08 ( -1.32906e-08 1.07157e-08 ) ergs/cm2
Time-resolved spectra
