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 -0.832 sec. to 147.444 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.54818 ( -0.0685422 0.0683094 )
Norm@50keV : 2.47113E-03 ( -8.82115e-05 8.80533e-05 )
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#Fit statistic : Chi-Squared = 71.20 using 59 PHA bins.
# Reduced chi-squared = 1.249 for 57 degrees of freedom
# Null hypothesis probability = 9.769402e-02
Photon flux (15-150 keV) in 148.3 sec: 0.312675 ( -0.011775 0.011824 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.45137e-06 ( -1.328e-07 1.33233e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.832 sec. to 147.444 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.44299 ( -0.144825 0.265303 )
Epeak [keV] : 276.708 ( -276.703 -276.703 )
Norm@50keV : 2.77529E-03 ( -0.000377183 0.00091383 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.70 using 59 PHA bins.
# Reduced chi-squared = 1.263 for 56 degrees of freedom
# Null hypothesis probability = 8.926002e-02
Photon flux (15-150 keV) in 148.3 sec: 0.310284 ( -0.013022 0.013047 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.42106e-06 ( -1.51334e-07 1.50363e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 75.040 sec. to 76.040 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.32887 ( -0.112059 0.11204 )
Norm@50keV : 2.06147E-02 ( -0.00129127 0.00128987 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.90 using 59 PHA bins.
# Reduced chi-squared = 0.8403 for 57 degrees of freedom
# Null hypothesis probability = 7.993613e-01
Photon flux (15-150 keV) in 1 sec: 2.47297 ( -0.15898 0.1593 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.02339e-07 ( -1.41215e-08 1.42019e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 75.040 sec. to 76.040 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.22503 ( -0.160489 0.443054 )
Epeak [keV] : 397.643 ( -397.875 -397.875 )
Norm@50keV : 2.31243E-02 ( -0.003662 0.0141079 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.71 using 59 PHA bins.
# Reduced chi-squared = 0.8520 for 56 degrees of freedom
# Null hypothesis probability = 7.768184e-01
Photon flux (15-150 keV) in 1 sec: 2.46086 ( -0.16597 0.16511 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.00969e-07 ( -1.5257e-08 1.45423e-08 ) ergs/cm2
Time-resolved spectra
