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 0.000 sec. to 4.800 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.10593 ( -0.270646 0.282394 )
Norm@50keV : 9.07738E-03 ( -0.00140522 0.00138963 )
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#Fit statistic : Chi-Squared = 43.91 using 59 PHA bins.
# Reduced chi-squared = 0.7703 for 57 degrees of freedom
# Null hypothesis probability = 8.982000e-01
Photon flux (15-150 keV) in 4.8 sec: 1.05353 ( -0.170603 0.17271 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.54738e-07 ( -7.04198e-08 7.07117e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 4.800 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.658941 ( -0.67964 1.46322 )
Epeak [keV] : 184.085 ( -184.066 -184.066 )
Norm@50keV : 1.38447E-02 ( -0.00595223 0.0359869 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.46 using 59 PHA bins.
# Reduced chi-squared = 0.7761 for 56 degrees of freedom
# Null hypothesis probability = 8.892216e-01
Photon flux (15-150 keV) in 4.8 sec: 1.02476 ( -0.186163 0.18662 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.47055e-07 ( -7.46453e-08 7.35173e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.300 sec. to 1.300 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.995766 ( -0.282064 0.298377 )
Norm@50keV : 2.32534E-02 ( -0.00380923 0.0037611 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.38 using 59 PHA bins.
# Reduced chi-squared = 0.9190 for 57 degrees of freedom
# Null hypothesis probability = 6.486212e-01
Photon flux (15-150 keV) in 1 sec: 2.67655 ( -0.44515 0.44866 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.51855e-07 ( -4.18402e-08 4.20927e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.300 sec. to 1.300 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.693966 ( -0.556996 1.50312 )
Epeak [keV] : 254.757 ( -254.751 -254.751 )
Norm@50keV : 3.14047E-02 ( -0.0115247 0.100352 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.20 using 59 PHA bins.
# Reduced chi-squared = 0.9321 for 56 degrees of freedom
# Null hypothesis probability = 6.194851e-01
Photon flux (15-150 keV) in 1 sec: 2.63830 ( -0.47081 0.46398 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.48353e-07 ( -4.55661e-08 4.4069e-08 ) ergs/cm2
Time-resolved spectra
