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 -3.100 sec. to 141.792 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.61265 ( -0.0847006 0.0842248 )
Norm@50keV : 1.85319E-03 ( -8.56258e-05 8.53154e-05 )
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#Fit statistic : Chi-Squared = 65.34 using 59 PHA bins.
# Reduced chi-squared = 1.146 for 57 degrees of freedom
# Null hypothesis probability = 2.095182e-01
Photon flux (15-150 keV) in 144.9 sec: 0.239094 ( -0.011046 0.011075 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.50789e-06 ( -1.24478e-07 1.2516e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.100 sec. to 141.792 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.61165 ( -0.0845674 0.28127 )
Epeak [keV] : 9999.07 ( -9999.32 -9999.32 )
Norm@50keV : 1.85548E-03 ( -8.4885e-05 0.000700449 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.35 using 59 PHA bins.
# Reduced chi-squared = 1.167 for 56 degrees of freedom
# Null hypothesis probability = 1.838163e-01
Photon flux (15-150 keV) in 144.9 sec: 0.239312 ( -0.011828 0.011029 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.51055e-06 ( -1.36565e-07 1.22736e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.044 sec. to 1.044 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.66311 ( -0.110134 0.108068 )
Norm@50keV : 2.22214E-02 ( -0.00152265 0.00151174 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.17 using 59 PHA bins.
# Reduced chi-squared = 1.021 for 57 degrees of freedom
# Null hypothesis probability = 4.319495e-01
Photon flux (15-150 keV) in 1 sec: 2.91434 ( -0.18626 0.18637 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.06433e-07 ( -1.49589e-08 1.50855e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.044 sec. to 1.044 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.777151 ( -0.489117 0.551621 )
Epeak [keV] : 64.9848 ( -10.1407 24.7061 )
Norm@50keV : 6.53423E-02 ( -0.028882 0.0615652 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.78 using 59 PHA bins.
# Reduced chi-squared = 0.8533 for 56 degrees of freedom
# Null hypothesis probability = 7.745905e-01
Photon flux (15-150 keV) in 1 sec: 2.81154 ( -0.19404 0.19416 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.92615e-07 ( -1.64539e-08 1.67239e-08 ) ergs/cm2
Time-resolved spectra
