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 -1.796 sec. to 15.852 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.81411 ( -0.147382 0.143235 )
Norm@50keV : 4.74708E-03 ( -0.000428446 0.000421681 )
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#Fit statistic : Chi-Squared = 56.00 using 59 PHA bins.
# Reduced chi-squared = 0.9825 for 57 degrees of freedom
# Null hypothesis probability = 5.126057e-01
Photon flux (15-150 keV) in 17.65 sec: 0.657787 ( -0.051072 0.0511 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.71107e-07 ( -7.0145e-08 7.11498e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.796 sec. to 15.852 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.62861 ( -0.562442 0.611539 )
Epeak [keV] : 89.3582 ( )
Norm@50keV : 6.01123E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.67 using 59 PHA bins.
# Reduced chi-squared = 0.9941 for 56 degrees of freedom
# Null hypothesis probability = 4.873852e-01
Photon flux (15-150 keV) in 17.65 sec: 0.652226 ( -0.053692 0.05351 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.56214e-07 ( -8.25016e-08 8.12662e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.024 sec. to 2.024 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.20429 ( -0.365754 0.383372 )
Norm@50keV : 9.05344E-03 ( -0.00165752 0.00165735 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.84 using 59 PHA bins.
# Reduced chi-squared = 1.015 for 57 degrees of freedom
# Null hypothesis probability = 4.439689e-01
Photon flux (15-150 keV) in 1 sec: 1.06333 ( -0.20264 0.20346 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.17508e-08 ( -1.90097e-08 1.92203e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.024 sec. to 2.024 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.20155 ( -0.344458 0.412172 )
Epeak [keV] : 1.00000E+04 ( -10000 -10000 )
Norm@50keV : 9.09559E-03 ( -0.00166515 -0.00909559 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.86 using 59 PHA bins.
# Reduced chi-squared = 1.033 for 56 degrees of freedom
# Null hypothesis probability = 4.063147e-01
Photon flux (15-150 keV) in 1 sec: 1.06976 ( -0.218146 0.20498 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.09829e-08 ( -1.82887e-08 1.99116e-08 ) ergs/cm2
Time-resolved spectra
