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 1.000 sec. to 65.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.78449 ( -0.311454 0.292568 )
Norm@50keV : 2.47621E-03 ( -0.000452055 0.000438447 )
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#Fit statistic : Chi-Squared = 57.06 using 59 PHA bins.
# Reduced chi-squared = 1.001 for 57 degrees of freedom
# Null hypothesis probability = 4.729754e-01
Photon flux (15-150 keV) in 64 sec: 0.339203 ( -0.056432 0.056578 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.46006e-06 ( -2.6791e-07 2.71153e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.000 sec. to 65.000 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.78897 ( -0.355263 0.297864 )
Epeak [keV] : 9999.36 ( -9999.35 -9999.36 )
Norm@50keV : 2.47290E-03 ( -0.00247715 0.00702307 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.06 using 59 PHA bins.
# Reduced chi-squared = 1.019 for 56 degrees of freedom
# Null hypothesis probability = 4.355343e-01
Photon flux (15-150 keV) in 64 sec: 0.339561 ( -0.057304 0.056423 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.46174e-06 ( -2.49386e-07 2.26444e-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:
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Parameters : value lower 90% higher 90%
Photon index: -2.30923 ( 2.30103 2.30103 )
Norm@50keV : 1.58389E-03 ( -0.00158701 0.00273209 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.88 using 59 PHA bins.
# Reduced chi-squared = 1.208 for 57 degrees of freedom
# Null hypothesis probability = 1.345919e-01
Photon flux (15-150 keV) in 1 sec: 0.277391 ( -0.277391 0.409946 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.51688e-08 ( 1 2.45568e-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: 9.99975 ( -11.984 -9.99996 )
Epeak [keV] : 64.5375 ( -28.0264 22.2579 )
Norm@50keV : 68.4758 ( -68.2911 405795 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.15 using 59 PHA bins.
# Reduced chi-squared = 1.181 for 56 degrees of freedom
# Null hypothesis probability = 1.664322e-01
Photon flux (15-150 keV) in 1 sec: 0.264905 ( -0.264905 0.395625 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.50374e-08 ( -2.07568e-08 2.47042e-08 ) ergs/cm2
Time-resolved spectra
