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 -0.072 sec. to 50.552 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.87136 ( -0.374857 0.352328 )
Norm@50keV : 3.55924E-03 ( -0.000951901 0.000938537 )
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#Fit statistic : Chi-Squared = 70.26 using 59 PHA bins.
# Reduced chi-squared = 1.233 for 57 degrees of freedom
# Null hypothesis probability = 1.115003e-01
Photon flux (15-150 keV) in 50.62 sec: 0.505134 ( -0.126857 0.127768 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.65414e-06 ( -4.34695e-07 4.43409e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.072 sec. to 50.552 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.43613 ( -3.38188 5.39705 )
Epeak [keV] : 46.4729 ( -6.63383 9.98502 )
Norm@50keV : 2.24565 ( -2.1831 1805.98 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.75 using 59 PHA bins.
# Reduced chi-squared = 1.013 for 56 degrees of freedom
# Null hypothesis probability = 4.467302e-01
Photon flux (15-150 keV) in 50.62 sec: 0.447189 ( -0.120636 0.127005 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.44013e-06 ( -3.72697e-07 4.11146e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.092 sec. to 0.908 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.1695 ( -0.233349 0.241263 )
Norm@50keV : 6.66306E-02 ( -0.0105309 0.0104566 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.19 using 59 PHA bins.
# Reduced chi-squared = 1.161 for 57 degrees of freedom
# Null hypothesis probability = 1.895037e-01
Photon flux (15-150 keV) in 1 sec: 0.188389 ( -0.027334 0.138299 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.82025e-07 ( -1.06002e-07 1.06073e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.092 sec. to 0.908 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.488726 ( -1.23757 1.77094 )
Epeak [keV] : 91.7061 ( -19.852 86.6182 )
Norm@50keV : 0.327372 ( -0.327374 1.25055 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.51 using 59 PHA bins.
# Reduced chi-squared = 1.081 for 56 degrees of freedom
# Null hypothesis probability = 3.162605e-01
Photon flux (15-150 keV) in 1 sec: 7.37137 ( -1.31472 1.33946 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.70363e-07 ( -1.12073e-07 1.10294e-07 ) ergs/cm2
Time-resolved spectra
