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 -35.592 sec. to 38.568 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.50801 ( -0.0502839 0.0503775 )
Norm@50keV : 2.29779E-02 ( -0.000676177 0.000675882 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 79.41 using 59 PHA bins.
# Reduced chi-squared = 1.393 for 57 degrees of freedom
# Null hypothesis probability = 2.656274e-02
Photon flux (15-150 keV) in 74.16 sec: 2.87483 ( -0.09747 0.09786 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.61466e-05 ( -4.76534e-07 4.76452e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -35.592 sec. to 38.568 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.918029 ( -0.224444 0.235741 )
Epeak [keV] : 107.860 ( -15.0945 30.2332 )
Norm@50keV : 4.14123E-02 ( -0.00812376 0.0106249 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.87 using 59 PHA bins.
# Reduced chi-squared = 1.033 for 56 degrees of freedom
# Null hypothesis probability = 4.059729e-01
Photon flux (15-150 keV) in 74.16 sec: 2.76374 ( -0.10397 0.10464 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.58395e-05 ( -4.95777e-07 4.9443e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.844 sec. to 3.844 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.57056 ( -0.0833532 0.0826836 )
Norm@50keV : 0.197801 ( -0.0103594 0.0103554 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.14 using 59 PHA bins.
# Reduced chi-squared = 1.318 for 57 degrees of freedom
# Null hypothesis probability = 5.401131e-02
Photon flux (15-150 keV) in 1 sec: 25.1928 ( -1.4062 1.4091 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.85708e-06 ( -1.01058e-07 1.01223e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.844 sec. to 3.844 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.86645 ( -0.359258 0.387248 )
Epeak [keV] : 89.7569 ( -14.502 36.2626 )
Norm@50keV : 0.421750 ( -0.132345 0.209822 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.26 using 59 PHA bins.
# Reduced chi-squared = 1.130 for 56 degrees of freedom
# Null hypothesis probability = 2.354337e-01
Photon flux (15-150 keV) in 1 sec: 24.5671 ( -1.4321 1.4401 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.83493e-06 ( -1.03599e-07 1.03455e-07 ) ergs/cm2
Time-resolved spectra
