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 -2.672 sec. to 52.056 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.35608 ( -0.0831225 0.0833385 )
Norm@50keV : 3.57321E-03 ( -0.000168773 0.000168739 )
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#Fit statistic : Chi-Squared = 58.02 using 59 PHA bins.
# Reduced chi-squared = 1.018 for 57 degrees of freedom
# Null hypothesis probability = 4.373934e-01
Photon flux (15-150 keV) in 54.73 sec: 0.431016 ( -0.021182 0.021218 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.90764e-06 ( -9.86492e-08 9.91242e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.672 sec. to 52.056 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.846591 ( -0.346317 0.377306 )
Epeak [keV] : 118.287 ( -29.8643 131.462 )
Norm@50keV : 6.30305E-03 ( -0.00197686 0.00319991 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.49 using 59 PHA bins.
# Reduced chi-squared = 0.9195 for 56 degrees of freedom
# Null hypothesis probability = 6.459442e-01
Photon flux (15-150 keV) in 54.73 sec: 0.419891 ( -0.022439 0.022445 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.83775e-06 ( -1.10773e-07 1.10328e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.492 sec. to 5.492 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2781 ( -0.188847 0.190844 )
Norm@50keV : 1.28997E-02 ( -0.00149229 0.00148949 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.38 using 59 PHA bins.
# Reduced chi-squared = 1.077 for 57 degrees of freedom
# Null hypothesis probability = 3.219324e-01
Photon flux (15-150 keV) in 1 sec: 1.53295 ( -0.17945 0.17965 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28183e-07 ( -1.64478e-08 1.65941e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.492 sec. to 5.492 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.676509 ( -0.684619 0.962922 )
Epeak [keV] : 110.133 ( -41.3185 -110.135 )
Norm@50keV : 2.61457E-02 ( -0.0141265 0.0527071 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.71 using 59 PHA bins.
# Reduced chi-squared = 1.066 for 56 degrees of freedom
# Null hypothesis probability = 3.422949e-01
Photon flux (15-150 keV) in 1 sec: 1.50443 ( -0.18477 0.1841 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.22476e-07 ( -1.86252e-08 1.83848e-08 ) ergs/cm2
Time-resolved spectra
