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 -0.608 sec. to 22.932 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.57293 ( -0.124996 0.123133 )
Norm@50keV : 3.24103E-03 ( -0.000240956 0.000239348 )
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#Fit statistic : Chi-Squared = 75.75 using 59 PHA bins.
# Reduced chi-squared = 1.329 for 57 degrees of freedom
# Null hypothesis probability = 4.898541e-02
Photon flux (15-150 keV) in 23.54 sec: 0.413084 ( -0.029125 0.029148 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.16073e-07 ( -5.77688e-08 5.84364e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.608 sec. to 22.932 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.740936 ( -0.549575 0.632466 )
Epeak [keV] : 71.8058 ( -13.8714 48.3201 )
Norm@50keV : 8.81318E-03 ( -0.00419825 0.00985906 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.66 using 59 PHA bins.
# Reduced chi-squared = 1.226 for 56 degrees of freedom
# Null hypothesis probability = 1.193269e-01
Photon flux (15-150 keV) in 23.54 sec: 0.396412 ( -0.031022 0.031012 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.63463e-07 ( -6.57588e-08 6.71483e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.632 sec. to 2.632 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.27602 ( -0.223172 0.224978 )
Norm@50keV : 9.03707E-03 ( -0.00119414 0.0011913 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.96 using 59 PHA bins.
# Reduced chi-squared = 0.9467 for 57 degrees of freedom
# Null hypothesis probability = 5.897724e-01
Photon flux (15-150 keV) in 1 sec: 1.07354 ( -0.142008 0.14214 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.98463e-08 ( -1.33994e-08 1.35869e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.632 sec. to 2.632 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.877058 ( -0.516212 0.944472 )
Epeak [keV] : 141.697 ( -141.696 -141.696 )
Norm@50keV : 1.43887E-02 ( -0.00634139 0.0277014 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.23 using 59 PHA bins.
# Reduced chi-squared = 0.9506 for 56 degrees of freedom
# Null hypothesis probability = 5.803140e-01
Photon flux (15-150 keV) in 1 sec: 1.05740 ( -0.145906 0.1457 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.69441e-08 ( -1.48749e-08 1.47533e-08 ) ergs/cm2
Time-resolved spectra
