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 -4.460 sec. to 2.480 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.89172 ( -0.129911 0.125964 )
Norm@50keV : 5.84995E-03 ( -0.000496972 0.000491087 )
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#Fit statistic : Chi-Squared = 60.81 using 59 PHA bins.
# Reduced chi-squared = 1.067 for 57 degrees of freedom
# Null hypothesis probability = 3.405497e-01
Photon flux (15-150 keV) in 6.94 sec: 0.836646 ( -0.05995 0.059973 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.73293e-07 ( -3.11485e-08 3.15714e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.460 sec. to 2.480 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.542608 ( -0.675866 0.805904 )
Epeak [keV] : 45.2509 ( -5.44932 8.40346 )
Norm@50keV : 3.44534E-02 ( -0.0201635 0.0659944 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.28 using 59 PHA bins.
# Reduced chi-squared = 0.8443 for 56 degrees of freedom
# Null hypothesis probability = 7.902438e-01
Photon flux (15-150 keV) in 6.94 sec: 0.793547 ( -0.062854 0.06314 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.2898e-07 ( -3.37714e-08 3.60085e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.280 sec. to 0.720 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.69573 ( -0.16787 0.162968 )
Norm@50keV : 1.22793E-02 ( -0.00134963 0.00133194 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.93 using 59 PHA bins.
# Reduced chi-squared = 1.069 for 57 degrees of freedom
# Null hypothesis probability = 3.364546e-01
Photon flux (15-150 keV) in 1 sec: 1.62846 ( -0.15964 0.15969 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.13747e-07 ( -1.30538e-08 1.32373e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.280 sec. to 0.720 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.653292 ( -0.784852 0.963291 )
Epeak [keV] : 56.0613 ( -10.8402 41.9071 )
Norm@50keV : 4.75750E-02 ( -0.0301275 0.120453 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.54 using 59 PHA bins.
# Reduced chi-squared = 0.9919 for 56 degrees of freedom
# Null hypothesis probability = 4.920764e-01
Photon flux (15-150 keV) in 1 sec: 1.57677 ( -0.16396 0.16431 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.03024e-07 ( -1.44472e-08 1.52475e-08 ) ergs/cm2
Time-resolved spectra
