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 -1.084 sec. to 75.128 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.65473 ( -0.0430464 0.0429695 )
Norm@50keV : 1.04085E-02 ( -0.000225937 0.0002259 )
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#Fit statistic : Chi-Squared 39.96 using 59 bins.
Reduced chi-squared = 0.701053
# Null hypothesis probability of 9.58e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 76.21 sec: 1.36127 ( -0.03391 0.03405 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.375e-06 ( -1.65555e-07 1.6553e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.084 sec. to 75.128 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.45056 ( -0.171268 0.178123 )
Epeak [keV] : 145.039 ( -43.3096 393.341 )
Norm@50keV : 1.29301E-02 ( -0.00209988 0.00262286 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 35.80 using 59 bins.
Reduced chi-squared = 0.639286
# Null hypothesis probability of 9.84e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 76.21 sec: 1.33671 ( -0.03907 0.03931 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.25691e-06 ( -1.92406e-07 1.91811e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.520 sec. to 0.480 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.17758 ( -0.0697294 0.0697086 )
Norm@50keV : 7.48113E-02 ( -0.0029893 0.0029892 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 58.40 using 59 bins.
Reduced chi-squared = 1.02456
# Null hypothesis probability of 4.24e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.321756 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.63959e-07 ( -3.45183e-08 3.46607e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.520 sec. to 0.480 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.593977 ( -0.297214 0.318422 )
Epeak [keV] : 132.808 ( -28.5789 78.0508 )
Norm@50keV : 0.139210 ( -0.0369165 0.0542434 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 46.48 using 59 bins.
Reduced chi-squared = 0.83
# Null hypothesis probability of 8.14e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 8.52865 ( -0.37357 0.37344 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.39009e-07 ( -3.74729e-08 3.73632e-08 ) ergs/cm2
Time-resolved spectra
