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 -8.360 sec. to 28.600 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.74574 ( -0.131162 0.128477 )
Norm@50keV : 2.64188E-03 ( -0.000213084 0.000210625 )
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#Fit statistic : Chi-Squared = 57.47 using 59 PHA bins.
# Reduced chi-squared = 1.008 for 57 degrees of freedom
# Null hypothesis probability = 4.574790e-01
Photon flux (15-150 keV) in 36.96 sec: 0.356684 ( -0.025593 0.025606 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.01347e-07 ( -7.51153e-08 7.61195e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -8.360 sec. to 28.600 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.26751 ( -0.516255 0.596717 )
Epeak [keV] : 68.3793 ( -17.8582 -68.3793 )
Norm@50keV : 4.84475E-03 ( -0.00226496 0.00538008 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.02 using 59 PHA bins.
# Reduced chi-squared = 0.9825 for 56 degrees of freedom
# Null hypothesis probability = 5.120749e-01
Photon flux (15-150 keV) in 36.96 sec: 0.349020 ( -0.02698 0.026884 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.57298e-07 ( -8.76684e-08 8.92048e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.292 sec. to 1.292 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.75359 ( -0.392687 0.362931 )
Norm@50keV : 5.42522E-03 ( -0.00135494 0.00129461 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.44 using 59 PHA bins.
# Reduced chi-squared = 0.8673 for 57 degrees of freedom
# Null hypothesis probability = 7.514427e-01
Photon flux (15-150 keV) in 1 sec: 0.734589 ( -0.148766 0.148768 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.00587e-08 ( -1.24845e-08 1.29746e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.292 sec. to 1.292 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.7409 ( -1.05029 1.428 )
Epeak [keV] : 801.898 ( -894.124 -894.134 )
Norm@50keV : 5.51814E-03 ( -0.00144527 0.0320243 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.44 using 59 PHA bins.
# Reduced chi-squared = 0.8828 for 56 degrees of freedom
# Null hypothesis probability = 7.198564e-01
Photon flux (15-150 keV) in 1 sec: 0.734298 ( -0.150589 0.149018 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.99839e-08 ( -1.42903e-08 1.08576e-08 ) ergs/cm2
Time-resolved spectra
