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 -72.268 sec. to 158.800 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.70796 ( -0.0368769 0.0368563 )
Norm@50keV : 5.93524E-03 ( -0.00010611 0.00010611 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.65 using 59 PHA bins.
# Reduced chi-squared = 0.6255 for 57 degrees of freedom
# Null hypothesis probability = 9.880496e-01
Photon flux (15-150 keV) in 231.1 sec: 0.790505 ( -0.017501 0.017599 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26937e-05 ( -2.29386e-07 2.29451e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -72.268 sec. to 158.800 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.67289 ( -0.0360784 0.146082 )
Epeak [keV] : 481.655 ( -826.844 -984.811 )
Norm@50keV : 6.15299E-03 ( -0.000193786 0.000934854 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.76 using 59 PHA bins.
# Reduced chi-squared = 0.6385 for 56 degrees of freedom
# Null hypothesis probability = 9.839685e-01
Photon flux (15-150 keV) in 231.1 sec: 0.789257 ( -0.020674 0.01861 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26765e-05 ( -2.67438e-07 2.4161e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 36.128 sec. to 37.128 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23136 ( -0.0768848 0.0770091 )
Norm@50keV : 3.33099E-02 ( -0.00146311 0.00146292 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.31 using 59 PHA bins.
# Reduced chi-squared = 0.9352 for 57 degrees of freedom
# Null hypothesis probability = 6.143438e-01
Photon flux (15-150 keV) in 1 sec: 3.92806 ( -0.17636 0.1765 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.35066e-07 ( -1.65583e-08 1.6624e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 36.128 sec. to 37.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.920093 ( -0.291372 0.313275 )
Epeak [keV] : 186.053 ( -67.577 1277.98 )
Norm@50keV : 4.68849E-02 ( -0.012407 0.0186132 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.97 using 59 PHA bins.
# Reduced chi-squared = 0.8923 for 56 degrees of freedom
# Null hypothesis probability = 7.012455e-01
Photon flux (15-150 keV) in 1 sec: 3.87515 ( -0.18307 0.18303 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.28405e-07 ( -1.79562e-08 1.78611e-08 ) ergs/cm2
Time-resolved spectra
