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 -111.856 sec. to 12.176 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.70732 ( -0.0970521 0.09593 )
Norm@50keV : 2.80113E-03 ( -0.000153958 0.000152876 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.42 using 59 PHA bins.
# Reduced chi-squared = 0.9547 for 57 degrees of freedom
# Null hypothesis probability = 5.726275e-01
Photon flux (15-150 keV) in 124 sec: 0.372992 ( -0.019054 0.019079 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.21464e-06 ( -1.8597e-07 1.87734e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -111.856 sec. to 12.176 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.40772 ( -0.339918 0.410011 )
Epeak [keV] : 91.2376 ( -29.3724 -91.2384 )
Norm@50keV : 4.04219E-03 ( -0.00132305 0.00258169 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.55 using 59 PHA bins.
# Reduced chi-squared = 0.9384 for 56 degrees of freedom
# Null hypothesis probability = 6.062838e-01
Photon flux (15-150 keV) in 124 sec: 0.366080 ( -0.020851 0.020837 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.10693e-06 ( -2.27534e-07 2.28497e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -13.868 sec. to -12.868 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.48132 ( -0.120625 0.119248 )
Norm@50keV : 2.22709E-02 ( -0.00168059 0.00167315 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 72.26 using 59 PHA bins.
# Reduced chi-squared = 1.268 for 57 degrees of freedom
# Null hypothesis probability = 8.385973e-02
Photon flux (15-150 keV) in 1 sec: 2.76662 ( -0.20161 0.20171 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.11963e-07 ( -1.75748e-08 1.77523e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -13.868 sec. to -12.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.388871 ( -0.55083 0.642573 )
Epeak [keV] : 70.4717 ( -11.5908 25.8139 )
Norm@50keV : 8.28883E-02 ( -0.0396163 0.0960287 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.22 using 59 PHA bins.
# Reduced chi-squared = 1.058 for 56 degrees of freedom
# Null hypothesis probability = 3.588502e-01
Photon flux (15-150 keV) in 1 sec: 2.65385 ( -0.20905 0.20903 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.9399e-07 ( -1.95002e-08 1.98161e-08 ) ergs/cm2
Time-resolved spectra
