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 -0.856 sec. to 246.496 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.53997 ( -0.325087 0.313478 )
Norm@50keV : 4.55305E-04 ( -9.62384e-05 9.46037e-05 )
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#Fit statistic : Chi-Squared 62.90 using 59 bins.
Reduced chi-squared = 1.10351
# Null hypothesis probability of 2.75e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 247.4 sec: 5.74748E-02 ( -0.011154 0.0111579 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06206e-06 ( -2.40462e-07 2.47964e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.856 sec. to 246.496 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: 0.773828 ( -1.98154 3.47286 )
Epeak [keV] : 51.5307 ( -10.2131 46.0256 )
Norm@50keV : 8.77865E-03 ( -0.0102916 0.72675 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 58.46 using 59 bins.
Reduced chi-squared = 1.04393
# Null hypothesis probability of 3.85e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 247.4 sec: 5.27578E-02 ( -0.0116738 0.0117977 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.50999e-07 ( -2.17903e-07 2.83097e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.884 sec. to 3.884 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.55158 ( -0.40871 0.394207 )
Norm@50keV : 8.14394E-03 ( -0.0020472 0.00199691 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 71.98 using 59 bins.
Reduced chi-squared = 1.26281
# Null hypothesis probability of 8.73e-02 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.03148 ( -0.238292 0.23844 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.66602e-08 ( -2.05011e-08 2.12144e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.884 sec. to 3.884 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.971568 ( -0.955975 2.23416 )
Epeak [keV] : 79.4422 ( -38.4625 -79.4337 )
Norm@50keV : 1.70776E-02 ( -0.0108295 0.273603 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 71.62 using 59 bins.
Reduced chi-squared = 1.27893
# Null hypothesis probability of 7.79e-02 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.01037 ( -0.246564 0.24564 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.20095e-08 ( -2.3017e-08 2.41296e-08 ) ergs/cm2
Time-resolved spectra
