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 0.060 sec. to 0.452 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.40944 ( -0.303467 0.299254 )
Norm@50keV : 2.06955E-02 ( -0.00456469 0.00456188 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.94 using 59 PHA bins.
# Reduced chi-squared = 1.157 for 57 degrees of freedom
# Null hypothesis probability = 1.952526e-01
Photon flux (15-150 keV) in 0.392 sec: 2.52626 ( -0.57323 0.5762 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.82322e-08 ( -1.80115e-08 1.80943e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.060 sec. to 0.452 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.40225 ( -1.77778 3.30513 )
Epeak [keV] : 66.5851 ( -13.1238 25.7583 )
Norm@50keV : 0.412443 ( -0.412444 10.6718 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.77 using 59 PHA bins.
# Reduced chi-squared = 1.014 for 56 degrees of freedom
# Null hypothesis probability = 4.461073e-01
Photon flux (15-150 keV) in 0.392 sec: 2.39281 ( -0.58849 0.59049 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.55188e-08 ( -1.93395e-08 1.95386e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.242 sec. to 0.758 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.63178 ( -0.353393 0.333691 )
Norm@50keV : 1.14598E-02 ( -0.00272308 0.00268404 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.99 using 59 PHA bins.
# Reduced chi-squared = 1.140 for 57 degrees of freedom
# Null hypothesis probability = 2.183141e-01
Photon flux (15-150 keV) in 1 sec: 1.48751 ( -0.33405 0.33466 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.0681e-07 ( -2.63556e-08 2.68896e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.242 sec. to 0.758 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.24041 ( -2.1879 3.99891 )
Epeak [keV] : 51.9308 ( -10.1401 26.3567 )
Norm@50keV : 0.381442 ( -0.405766 45.3047 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.07 using 59 PHA bins.
# Reduced chi-squared = 1.055 for 56 degrees of freedom
# Null hypothesis probability = 3.639494e-01
Photon flux (15-150 keV) in 1 sec: 1.37142 ( -0.35057 0.35144 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.12914e-08 ( -2.48146e-08 2.88133e-08 ) ergs/cm2
Time-resolved spectra
