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 -6.160 sec. to 4.308 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.35226 ( -0.0444226 0.0445016 )
Norm@50keV : 2.98586E-02 ( -0.000748457 0.000748359 )
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#Fit statistic : Chi-Squared = 90.26 using 59 PHA bins.
# Reduced chi-squared = 1.584 for 57 degrees of freedom
# Null hypothesis probability = 3.293068e-03
Photon flux (15-150 keV) in 10.47 sec: 3.59882 ( -0.09822 0.09844 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.05209e-06 ( -8.01032e-08 8.02353e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.160 sec. to 4.308 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.812013 ( -0.191067 0.199335 )
Epeak [keV] : 124.449 ( -19.0295 36.7099 )
Norm@50keV : 5.21105E-02 ( -0.00909516 0.0115217 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.28 using 59 PHA bins.
# Reduced chi-squared = 1.166 for 56 degrees of freedom
# Null hypothesis probability = 1.854768e-01
Photon flux (15-150 keV) in 10.47 sec: 3.48422 ( -0.10464 0.10498 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.97048e-06 ( -8.61335e-08 8.59002e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.108 sec. to 2.108 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.950934 ( -0.0783464 0.0792066 )
Norm@50keV : 5.64013E-02 ( -0.00262931 0.00262416 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.76 using 59 PHA bins.
# Reduced chi-squared = 1.083 for 57 degrees of freedom
# Null hypothesis probability = 3.100333e-01
Photon flux (15-150 keV) in 1 sec: 6.48008 ( -0.30527 0.30553 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.20912e-07 ( -3.07653e-08 3.08514e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.108 sec. to 2.108 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.587068 ( -0.318577 0.343211 )
Epeak [keV] : 229.803 ( -83.0571 770.109 )
Norm@50keV : 8.12535E-02 ( -0.0216616 0.0320138 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.94 using 59 PHA bins.
# Reduced chi-squared = 1.035 for 56 degrees of freedom
# Null hypothesis probability = 4.037020e-01
Photon flux (15-150 keV) in 1 sec: 6.40471 ( -0.3121 0.31232 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.1379e-07 ( -3.19682e-08 3.18345e-08 ) ergs/cm2
Time-resolved spectra
