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 -47.000 sec. to 97.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.03972 ( -0.239618 0.224807 )
Norm@50keV : 6.44359E-04 ( -0.000108093 0.000106091 )
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#Fit statistic : Chi-Squared = 77.88 using 59 PHA bins.
# Reduced chi-squared = 1.366 for 57 degrees of freedom
# Null hypothesis probability = 3.447550e-02
Photon flux (15-150 keV) in 144 sec: 9.84696E-02 ( -0.0121328 0.0121334 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.57951e-07 ( -1.31272e-07 1.35812e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -47.000 sec. to 97.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.803256 ( -1.08101 1.5783 )
Epeak [keV] : 36.2619 ( -17.5005 13.6324 )
Norm@50keV : 3.73031E-03 ( -0.0037309 0.0342969 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 73.88 using 59 PHA bins.
# Reduced chi-squared = 1.319 for 56 degrees of freedom
# Null hypothesis probability = 5.491923e-02
Photon flux (15-150 keV) in 144 sec: 9.46596E-02 ( -0.0123877 0.0124734 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.45852e-07 ( -1.3627e-07 1.59489e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 56.500 sec. to 57.500 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.70554 ( -1.42726 1.18382 )
Norm@50keV : 1.58533E-03 ( -0.00120459 0.00117106 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 33.35 using 59 PHA bins.
# Reduced chi-squared = 0.5851 for 57 degrees of freedom
# Null hypothesis probability = 9.947971e-01
Photon flux (15-150 keV) in 1 sec: 0.210956 ( -0.140341 0.140378 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.46879e-08 ( -1.0581e-08 1.2212e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 56.500 sec. to 57.500 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.103841 ( -2.24984 0.0587307 )
Epeak [keV] : 48.9554 ( )
Norm@50keV : 1.37441E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 32.67 using 59 PHA bins.
# Reduced chi-squared = 0.5833 for 56 degrees of freedom
# Null hypothesis probability = 9.946432e-01
Photon flux (15-150 keV) in 1 sec: 0.199746 ( -0.132879 0.13896 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.20487e-08 ( -8.58771e-09 1.28875e-08 ) ergs/cm2
Time-resolved spectra
