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 -0.240 sec. to 26.576 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.7812 ( -0.295251 0.278611 )
Norm@50keV : 1.34819E-03 ( -0.000266005 0.000259217 )
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#Fit statistic : Chi-Squared = 65.74 using 59 PHA bins.
# Reduced chi-squared = 1.153 for 57 degrees of freedom
# Null hypothesis probability = 1.998164e-01
Photon flux (15-150 keV) in 26.82 sec: 0.184450 ( -0.030088 0.030087 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.33179e-07 ( -6.58611e-08 6.81477e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.240 sec. to 26.576 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.767125 ( -1.25601 1.67488 )
Epeak [keV] : 49.6334 ( -14.8131 -49.6336 )
Norm@50keV : 5.32061E-03 ( -0.00532052 0.0471835 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.74 using 59 PHA bins.
# Reduced chi-squared = 1.138 for 56 degrees of freedom
# Null hypothesis probability = 2.228788e-01
Photon flux (15-150 keV) in 26.82 sec: 0.178535 ( -0.030635 0.030853 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.97131e-07 ( -6.86611e-08 7.92772e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.876 sec. to 3.876 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.49676 ( -0.464579 0.456278 )
Norm@50keV : 4.64930E-03 ( -0.00134404 0.001316 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.46 using 59 PHA bins.
# Reduced chi-squared = 1.026 for 57 degrees of freedom
# Null hypothesis probability = 4.214304e-01
Photon flux (15-150 keV) in 1 sec: 0.579926 ( -0.157594 0.157739 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.41347e-08 ( -1.36424e-08 1.41601e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.876 sec. to 3.876 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.0433537 ( -1.98086 5.73376 )
Epeak [keV] : 55.6053 ( -28.3185 -54.4878 )
Norm@50keV : 3.54719E-02 ( -0.0427686 71.069 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.65 using 59 PHA bins.
# Reduced chi-squared = 1.029 for 56 degrees of freedom
# Null hypothesis probability = 4.141636e-01
Photon flux (15-150 keV) in 1 sec: 0.543888 ( -0.170057 0.173148 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.58311e-08 ( -1.34563e-08 1.99594e-08 ) ergs/cm2
Time-resolved spectra
