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 -10.936 sec. to 108.696 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.36624 ( -0.117355 0.117736 )
Norm@50keV : 5.77871E-03 ( -0.000394839 0.000394813 )
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#Fit statistic : Chi-Squared = 48.09 using 59 PHA bins.
# Reduced chi-squared = 0.8436 for 57 degrees of freedom
# Null hypothesis probability = 7.937390e-01
Photon flux (15-150 keV) in 119.6 sec: 0.698547 ( -0.050368 0.050487 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.72684e-06 ( -4.93067e-07 4.94887e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -10.936 sec. to 108.696 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.03462 ( -0.384326 0.507761 )
Epeak [keV] : 158.704 ( -65.3168 -158.705 )
Norm@50keV : 8.28267E-03 ( -0.00273645 0.00582929 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.58 using 59 PHA bins.
# Reduced chi-squared = 0.8318 for 56 degrees of freedom
# Null hypothesis probability = 8.110386e-01
Photon flux (15-150 keV) in 119.6 sec: 0.688590 ( -0.052228 0.052278 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.62066e-06 ( -5.21766e-07 5.18894e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.972 sec. to 1.972 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.18062 ( -0.325579 0.326713 )
Norm@50keV : 4.23487E-02 ( -0.00824776 0.0082347 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.76 using 59 PHA bins.
# Reduced chi-squared = 0.9607 for 57 degrees of freedom
# Null hypothesis probability = 5.596512e-01
Photon flux (15-150 keV) in 1 sec: 4.95775 ( -1.00173 1.00524 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.32076e-07 ( -8.99863e-08 9.00676e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.972 sec. to 1.972 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.934864 ( 0.934725 1.71219 )
Epeak [keV] : 262.386 ( -262.263 -262.263 )
Norm@50keV : 5.41692E-02 ( -0.019479 0.213941 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.66 using 59 PHA bins.
# Reduced chi-squared = 0.9761 for 56 degrees of freedom
# Null hypothesis probability = 5.255375e-01
Photon flux (15-150 keV) in 1 sec: 4.92759 ( -1.01959 1.01521 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.078e-08 ( 0 0 ) ergs/cm2
Time-resolved spectra
