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 -49.688 sec. to 114.392 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.47035 ( -0.0961198 0.0959201 )
Norm@50keV : 7.25621E-03 ( -0.000390158 0.000389598 )
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#Fit statistic : Chi-Squared = 69.05 using 59 PHA bins.
# Reduced chi-squared = 1.211 for 57 degrees of freedom
# Null hypothesis probability = 1.316289e-01
Photon flux (15-150 keV) in 164.1 sec: 0.898851 ( -0.050508 0.05062 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.13543e-05 ( -6.59561e-07 6.62534e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -49.688 sec. to 114.392 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2612 ( -0.257336 0.394138 )
Epeak [keV] : 186.047 ( -89.221 -186.047 )
Norm@50keV : 9.15712E-03 ( -0.00218546 0.00488484 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.10 using 59 PHA bins.
# Reduced chi-squared = 1.216 for 56 degrees of freedom
# Null hypothesis probability = 1.288011e-01
Photon flux (15-150 keV) in 164.1 sec: 0.888952 ( -0.053299 0.053343 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.12003e-05 ( -7.18886e-07 7.14308e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 77.948 sec. to 78.948 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.7262 ( -0.376896 0.329787 )
Norm@50keV : 2.14661E-02 ( -0.00526091 0.0050797 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.35 using 59 PHA bins.
# Reduced chi-squared = 0.9360 for 57 degrees of freedom
# Null hypothesis probability = 6.127287e-01
Photon flux (15-150 keV) in 1 sec: 2.87766 ( -0.63058 0.63089 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.98399e-07 ( -4.92913e-08 4.97486e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 77.948 sec. to 78.948 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.703521 ( -1.53319 1.87798 )
Epeak [keV] : 67.6162 ( -38.5649 -67.6153 )
Norm@50keV : 6.87718E-02 ( -0.0687857 0.485301 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.80 using 59 PHA bins.
# Reduced chi-squared = 0.9250 for 56 degrees of freedom
# Null hypothesis probability = 6.344558e-01
Photon flux (15-150 keV) in 1 sec: 2.84492 ( -0.63652 0.63431 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.98861e-07 ( -5.02469e-08 5.07823e-08 ) ergs/cm2
Time-resolved spectra
