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 -74.608 sec. to 29.840 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.80865 ( -0.128332 0.125385 )
Norm@50keV : 1.25243E-03 ( -9.66337e-05 9.53768e-05 )
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#Fit statistic : Chi-Squared = 82.01 using 59 PHA bins.
# Reduced chi-squared = 1.439 for 57 degrees of freedom
# Null hypothesis probability = 1.667272e-02
Photon flux (15-150 keV) in 104.4 sec: 0.173174 ( -0.011528 0.011537 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.20356e-06 ( -9.40313e-08 9.53792e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -74.608 sec. to 29.840 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.47153 ( -0.423192 0.547273 )
Epeak [keV] : 69.5255 ( -21.0795 -69.5256 )
Norm@50keV : 1.92046E-03 ( -0.000734201 0.00188436 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 80.63 using 59 PHA bins.
# Reduced chi-squared = 1.440 for 56 degrees of freedom
# Null hypothesis probability = 1.725037e-02
Photon flux (15-150 keV) in 104.4 sec: 0.170093 ( -0.012355 0.012318 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.15862e-06 ( -1.1243e-07 1.14209e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.332 sec. to 2.332 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.71558 ( -0.192624 0.185776 )
Norm@50keV : 8.89560E-03 ( -0.00109248 0.00107293 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.17 using 59 PHA bins.
# Reduced chi-squared = 1.143 for 57 degrees of freedom
# Null hypothesis probability = 2.138199e-01
Photon flux (15-150 keV) in 1 sec: 1.18799 ( -0.12514 0.12515 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.22773e-08 ( -1.04896e-08 1.07114e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.332 sec. to 2.332 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.08032 ( -0.705121 0.871225 )
Epeak [keV] : 63.0442 ( -17.8587 -63.0442 )
Norm@50keV : 2.02451E-02 ( -0.0117881 0.0426242 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.92 using 59 PHA bins.
# Reduced chi-squared = 1.124 for 56 degrees of freedom
# Null hypothesis probability = 2.446049e-01
Photon flux (15-150 keV) in 1 sec: 1.15832 ( -0.12926 0.1294 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.67609e-08 ( -1.18347e-08 1.23088e-08 ) ergs/cm2
Time-resolved spectra
