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 -5.120 sec. to 24.480 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.53516 ( -0.17012 0.167276 )
Norm@50keV : 2.26995E-03 ( -0.000217189 0.000214728 )
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#Fit statistic : Chi-Squared = 50.40 using 59 PHA bins.
# Reduced chi-squared = 0.8843 for 57 degrees of freedom
# Null hypothesis probability = 7.191615e-01
Photon flux (15-150 keV) in 29.6 sec: 0.286151 ( -0.025761 0.02579 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.33988e-07 ( -6.6885e-08 6.79714e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -5.120 sec. to 24.480 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.53282 ( -0.829946 0.575962 )
Epeak [keV] : 9829.92 ( -9517.87 -9517.87 )
Norm@50keV : 2.27630E-03 ( -0.000602365 0.00260206 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.40 using 59 PHA bins.
# Reduced chi-squared = 0.9000 for 56 degrees of freedom
# Null hypothesis probability = 6.858528e-01
Photon flux (15-150 keV) in 29.6 sec: 0.285711 ( -0.027266 0.026023 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.32312e-07 ( -7.49703e-08 6.89035e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.596 sec. to 3.596 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.92108 ( -0.428463 0.393406 )
Norm@50keV : 5.26989E-03 ( -0.00142221 0.00133456 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.79 using 59 PHA bins.
# Reduced chi-squared = 0.9087 for 57 degrees of freedom
# Null hypothesis probability = 6.701560e-01
Photon flux (15-150 keV) in 1 sec: 0.763189 ( -0.14085 0.140877 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.84697e-08 ( -1.19834e-08 1.28034e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.596 sec. to 3.596 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.69549 ( -0.258513 0.882697 )
Epeak [keV] : 225.343 ( )
Norm@50keV : 2.09788E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.29 using 59 PHA bins.
# Reduced chi-squared = 0.8802 for 56 degrees of freedom
# Null hypothesis probability = 7.248097e-01
Photon flux (15-150 keV) in 1 sec: 0.665123 ( -0.214997 0.210949 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.36445e-08 ( -1.4613e-08 1.23132e-08 ) ergs/cm2
Time-resolved spectra
