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 0.000 sec. to 9.471 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.25357 ( -0.0970393 0.0976234 )
Norm@50keV : 1.42985E-02 ( -0.000748022 0.000747993 )
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#Fit statistic : Chi-Squared = 56.05 using 59 PHA bins.
# Reduced chi-squared = 0.9833 for 57 degrees of freedom
# Null hypothesis probability = 5.107855e-01
Photon flux (15-150 keV) in 9.471 sec: 1.69212 ( -0.09297 0.09324 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.35418e-06 ( -7.79617e-08 7.82885e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 9.471 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.25062 ( -0.0966737 0.298088 )
Epeak [keV] : 9999.15 ( -9999.28 -9999.28 )
Norm@50keV : 1.43622E-02 ( -0.000751167 0.000751223 )
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#Fit statistic : Chi-Squared = 56.06 using 59 PHA bins.
# Reduced chi-squared = 1.001 for 56 degrees of freedom
# Null hypothesis probability = 4.724837e-01
Photon flux (15-150 keV) in 9.471 sec: 1.69885 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.35924e-06 ( -1.07235e-07 7.39238e-08 ) ergs/cm2
1-s peak spectrum fit
1-s peak spectrum unavailable, likely because there are no event data in the 1-s peak range.
Time-resolved spectra