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 -209.004 sec. to 98.308 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.51396 ( -0.054271 0.05421 )
Norm@50keV : 2.73177E-03 ( -7.55408e-05 7.55037e-05 )
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#Fit statistic : Chi-Squared = 40.99 using 59 PHA bins.
# Reduced chi-squared = 0.7192 for 57 degrees of freedom
# Null hypothesis probability = 9.456494e-01
Photon flux (15-150 keV) in 307.3 sec: 0.342336 ( -0.010269 0.0103 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.94681e-06 ( -2.36131e-07 2.36757e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -209.004 sec. to 98.308 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.42644 ( -0.119048 0.217727 )
Epeak [keV] : 347.027 ( -347.965 -347.965 )
Norm@50keV : 3.00412E-03 ( -0.000331884 0.000777682 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.49 using 59 PHA bins.
# Reduced chi-squared = 0.7231 for 56 degrees of freedom
# Null hypothesis probability = 9.409896e-01
Photon flux (15-150 keV) in 307.3 sec: 0.340021 ( -0.011587 0.011566 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.88811e-06 ( -2.74646e-07 2.71555e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -190.720 sec. to -189.720 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.05748 ( -0.150812 0.152917 )
Norm@50keV : 2.18813E-02 ( -0.00181142 0.00181036 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.54 using 59 PHA bins.
# Reduced chi-squared = 0.7463 for 57 degrees of freedom
# Null hypothesis probability = 9.230118e-01
Photon flux (15-150 keV) in 1 sec: 2.52866 ( -0.21275 0.2131 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.32001e-07 ( -2.18459e-08 2.20144e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -190.720 sec. to -189.720 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.05224 ( -0.207665 0.361341 )
Epeak [keV] : 9999.33 ( -9999.34 -9999.34 )
Norm@50keV : 2.20044E-02 ( -0.00181827 0.0103387 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.56 using 59 PHA bins.
# Reduced chi-squared = 0.7600 for 56 degrees of freedom
# Null hypothesis probability = 9.072788e-01
Photon flux (15-150 keV) in 1 sec: 2.53747 ( -0.22221 0.20362 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.32697e-07 ( -2.63776e-08 1.47203e-08 ) ergs/cm2
Time-resolved spectra
