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 12.008 sec. to 61.160 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.76692 ( -0.261683 0.24674 )
Norm@50keV : 5.70431E-03 ( -0.000959538 0.000935433 )
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#Fit statistic : Chi-Squared = 52.33 using 59 PHA bins.
# Reduced chi-squared = 0.9180 for 57 degrees of freedom
# Null hypothesis probability = 6.508069e-01
Photon flux (15-150 keV) in 49.15 sec: 0.776226 ( -0.109259 0.109273 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.58514e-06 ( -4.3986e-07 4.52273e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 12.008 sec. to 61.160 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.877763 ( -0.991502 1.35218 )
Epeak [keV] : 54.7667 ( -15.5493 -54.7667 )
Norm@50keV : 1.80173E-02 ( -0.0180173 0.0861454 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.27 using 59 PHA bins.
# Reduced chi-squared = 0.8978 for 56 degrees of freedom
# Null hypothesis probability = 6.904241e-01
Photon flux (15-150 keV) in 49.15 sec: 0.750342 ( -0.112937 0.113297 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.3667e-06 ( -4.70066e-07 5.13971e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 26.836 sec. to 27.836 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.7165 ( -0.394995 0.411717 )
Norm@50keV : 1.24509E-02 ( -0.00468114 0.00467152 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.90 using 59 PHA bins.
# Reduced chi-squared = 0.8229 for 57 degrees of freedom
# Null hypothesis probability = 8.275773e-01
Photon flux (15-150 keV) in 1 sec: 1.66775 ( -0.680424 0.69702 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.15178e-07 ( -4.2941e-08 4.29687e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 26.836 sec. to 27.836 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.69724 ( -2.30785 -2.6992 )
Epeak [keV] : 65.2885 ( -17.5683 13.5185 )
Norm@50keV : 1.09483 ( -1.09597 5608.44 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 33.47 using 59 PHA bins.
# Reduced chi-squared = 0.5978 for 56 degrees of freedom
# Null hypothesis probability = 9.927075e-01
Photon flux (15-150 keV) in 1 sec: 1.91913 ( -0.68663 0.64312 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.61395e-07 ( -6.94051e-08 5.13503e-08 ) ergs/cm2
Time-resolved spectra
