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 -14.400 sec. to 72.928 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.84191 ( -0.194949 0.186148 )
Norm@50keV : 1.55808E-03 ( -0.000196969 0.000193094 )
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#Fit statistic : Chi-Squared = 45.35 using 59 PHA bins.
# Reduced chi-squared = 0.7956 for 57 degrees of freedom
# Null hypothesis probability = 8.670292e-01
Photon flux (15-150 keV) in 87.33 sec: 0.218300 ( -0.023076 0.023082 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25148e-06 ( -1.5714e-07 1.60058e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -14.400 sec. to 72.928 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.01902 ( -0.772679 0.933418 )
Epeak [keV] : 52.4351 ( -12.563 95.0633 )
Norm@50keV : 4.47506E-03 ( -0.00277359 0.0101533 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.01 using 59 PHA bins.
# Reduced chi-squared = 0.7501 for 56 degrees of freedom
# Null hypothesis probability = 9.173514e-01
Photon flux (15-150 keV) in 87.33 sec: 0.211713 ( -0.02386 0.023867 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.16403e-06 ( -1.67126e-07 1.76738e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 5.892 sec. to 6.892 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.41322 ( -0.705999 0.709947 )
Norm@50keV : 4.39175E-03 ( -0.00172617 0.00168586 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.04 using 59 PHA bins.
# Reduced chi-squared = 1.106 for 57 degrees of freedom
# Null hypothesis probability = 2.712414e-01
Photon flux (15-150 keV) in 1 sec: 0.536470 ( -0.205609 0.206816 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.23282e-08 ( -1.7776e-08 1.85848e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 5.892 sec. to 6.892 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.00062 ( -7.50519 7.01094 )
Epeak [keV] : 115.103 ( -117.329 -117.329 )
Norm@50keV : 7.25398E-03 ( -0.00444932 46.4204 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.99 using 59 PHA bins.
# Reduced chi-squared = 1.125 for 56 degrees of freedom
# Null hypothesis probability = 2.427891e-01
Photon flux (15-150 keV) in 1 sec: 0.527513 ( -0.22669 0.21307 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.06631e-08 ( -2.10268e-08 1.99714e-08 ) ergs/cm2
Time-resolved spectra
