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 -3.896 sec. to 9.544 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.66734 ( -0.122046 0.120095 )
Norm@50keV : 1.43326E-02 ( -0.00106796 0.00106136 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.98 using 59 bins.
Reduced chi-squared = 0.771579
# Null hypothesis probability of 8.97e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 13.44 sec: 1.88240 ( -0.13619 0.13636 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.78878e-06 ( -1.39902e-07 1.4087e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.896 sec. to 9.544 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.1071 ( -0.484191 0.543304 )
Epeak [keV] : 77.6276 ( -18.2321 152.887 )
Norm@50keV : 2.79617E-02 ( -0.012035 0.0247284 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 40.01 using 59 bins.
Reduced chi-squared = 0.714464
# Null hypothesis probability of 9.47e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 13.44 sec: 1.84061 ( -0.14103 0.14102 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.72211e-06 ( -1.52145e-07 1.52625e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.684 sec. to 1.684 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.54691 ( -0.254002 0.24328 )
Norm@50keV : 2.59553E-02 ( -0.0040113 0.00397818 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 46.14 using 59 bins.
Reduced chi-squared = 0.809474
# Null hypothesis probability of 8.48e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 3.28295 ( -0.50522 0.50601 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.44489e-07 ( -4.03199e-08 4.0475e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.684 sec. to 1.684 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29927 ( -0.488773 1.04244 )
Epeak [keV] : 154.407 ( -154.406 -154.406 )
Norm@50keV : 3.41761E-02 ( -0.025347 0.0701244 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 45.91 using 59 bins.
Reduced chi-squared = 0.819821
# Null hypothesis probability of 8.30e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 3.26276 ( -0.51075 0.51114 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.43461e-07 ( -4.11218e-08 4.09e-08 ) ergs/cm2
Time-resolved spectra
