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 -68.980 sec. to 62.660 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.87892 ( -0.0871586 0.0858404 )
Norm@50keV : 2.10925E-03 ( -0.000113307 0.000112545 )
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#Fit statistic : Chi-Squared = 69.73 using 59 PHA bins.
# Reduced chi-squared = 1.223 for 57 degrees of freedom
# Null hypothesis probability = 1.200132e-01
Photon flux (15-150 keV) in 131.6 sec: 0.300046 ( -0.014657 0.014674 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.55215e-06 ( -1.36151e-07 1.37134e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -68.980 sec. to 62.660 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.939724 ( -0.401042 0.443978 )
Epeak [keV] : 49.8555 ( -5.35507 8.06494 )
Norm@50keV : 6.91117E-03 ( -0.00271487 0.00516203 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.62 using 59 PHA bins.
# Reduced chi-squared = 0.9218 for 56 degrees of freedom
# Null hypothesis probability = 6.411172e-01
Photon flux (15-150 keV) in 131.6 sec: 0.286294 ( -0.015625 0.015647 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.33623e-06 ( -1.55479e-07 1.58744e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 17.596 sec. to 18.596 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.52253 ( -0.230223 0.22706 )
Norm@50keV : 1.01785E-02 ( -0.00137304 0.00135987 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.20 using 59 PHA bins.
# Reduced chi-squared = 1.021 for 57 degrees of freedom
# Null hypothesis probability = 4.308826e-01
Photon flux (15-150 keV) in 1 sec: 1.27856 ( -0.16875 0.16906 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.62255e-08 ( -1.40902e-08 1.42459e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 17.596 sec. to 18.596 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.46115 ( -1.25295 0.961605 )
Epeak [keV] : 398.739 ( -470.555 -470.555 )
Norm@50keV : 1.09435E-02 ( -0.00891693 0.0222807 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.20 using 59 PHA bins.
# Reduced chi-squared = 1.039 for 56 degrees of freedom
# Null hypothesis probability = 3.944201e-01
Photon flux (15-150 keV) in 1 sec: 1.27589 ( -0.1738 0.17078 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.58363e-08 ( -1.54559e-08 1.45106e-08 ) ergs/cm2
Time-resolved spectra
