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 -3.820 sec. to 13.492 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29945 ( -0.0806595 0.0811009 )
Norm@50keV : 6.59113E-03 ( -0.000304275 0.000304275 )
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#Fit statistic : Chi-Squared = 60.75 using 59 PHA bins.
# Reduced chi-squared = 1.066 for 57 degrees of freedom
# Null hypothesis probability = 3.422755e-01
Photon flux (15-150 keV) in 17.31 sec: 0.786268 ( -0.038042 0.038105 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.12773e-06 ( -5.6617e-08 5.67984e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.820 sec. to 13.492 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.846809 ( -0.319228 0.344956 )
Epeak [keV] : 136.898 ( -37.3648 180.946 )
Norm@50keV : 1.07937E-02 ( -0.00309845 0.00474308 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.70 using 59 PHA bins.
# Reduced chi-squared = 0.9767 for 56 degrees of freedom
# Null hypothesis probability = 5.243072e-01
Photon flux (15-150 keV) in 17.31 sec: 0.769056 ( -0.039865 0.039887 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.09574e-06 ( -6.15802e-08 6.13778e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 10.224 sec. to 11.224 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.24562 ( -0.158425 0.159683 )
Norm@50keV : 1.40582E-02 ( -0.00135001 0.00134911 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.05 using 59 PHA bins.
# Reduced chi-squared = 0.8605 for 57 degrees of freedom
# Null hypothesis probability = 7.640455e-01
Photon flux (15-150 keV) in 1 sec: 1.66154 ( -0.16247 0.16265 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.40874e-07 ( -1.50191e-08 1.51136e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 10.224 sec. to 11.224 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.791392 ( -0.523307 0.668279 )
Epeak [keV] : 139.663 ( -55.5806 -139.662 )
Norm@50keV : 2.34852E-02 ( -0.0101381 0.0252811 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.27 using 59 PHA bins.
# Reduced chi-squared = 0.8442 for 56 degrees of freedom
# Null hypothesis probability = 7.903997e-01
Photon flux (15-150 keV) in 1 sec: 1.63839 ( -0.16544 0.16542 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.37151e-07 ( -1.61218e-08 1.5993e-08 ) ergs/cm2
Time-resolved spectra
