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 -5.600 sec. to 8.400 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.8563 ( -0.263331 0.248692 )
Norm@50keV : 1.89106E-03 ( -0.000330024 0.000321523 )
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#Fit statistic : Chi-Squared = 57.21 using 59 PHA bins.
# Reduced chi-squared = 1.004 for 57 degrees of freedom
# Null hypothesis probability = 4.671410e-01
Photon flux (15-150 keV) in 14 sec: 0.266507 ( -0.036889 0.036889 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.43454e-07 ( -4.15351e-08 4.29423e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -5.600 sec. to 8.400 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.05742 ( -1.05722 1.45052 )
Epeak [keV] : 47.3897 ( -47.1732 -47.3891 )
Norm@50keV : 5.62933E-03 ( -0.00562973 0.0363801 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.71 using 59 PHA bins.
# Reduced chi-squared = 0.9949 for 56 degrees of freedom
# Null hypothesis probability = 4.856560e-01
Photon flux (15-150 keV) in 14 sec: 0.258625 ( -0.038137 0.038359 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.20556e-07 ( -4.58419e-08 5.25228e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.400 sec. to 2.400 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.84504 ( -0.510966 0.455955 )
Norm@50keV : 3.95497E-03 ( -0.00130033 0.00122933 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.08 using 59 PHA bins.
# Reduced chi-squared = 1.194 for 57 degrees of freedom
# Null hypothesis probability = 1.494907e-01
Photon flux (15-150 keV) in 1 sec: 0.554826 ( -0.139679 0.139685 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.63739e-08 ( -1.1352e-08 1.20478e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.400 sec. to 2.400 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.64002 ( -0.621954 2.1604 )
Epeak [keV] : 72.6463 ( )
Norm@50keV : 5.22281E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.03 using 59 PHA bins.
# Reduced chi-squared = 1.215 for 56 degrees of freedom
# Null hypothesis probability = 1.300496e-01
Photon flux (15-150 keV) in 1 sec: 0.551144 ( -0.140324 0.141586 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.54585e-08 ( -1.26109e-08 1.12956e-08 ) ergs/cm2
Time-resolved spectra
