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 -23.460 sec. to 9.320 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.957979 ( -0.180399 0.188244 )
Norm@50keV : 3.12414E-03 ( -0.000339357 0.000336501 )
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#Fit statistic : Chi-Squared = 59.63 using 59 PHA bins.
# Reduced chi-squared = 1.046 for 57 degrees of freedom
# Null hypothesis probability = 3.800906e-01
Photon flux (15-150 keV) in 32.78 sec: 0.359022 ( -0.039413 0.039597 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.12447e-06 ( -1.23115e-07 1.23598e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -23.460 sec. to 9.320 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.412156 ( -0.686354 0.885794 )
Epeak [keV] : 170.655 ( )
Norm@50keV : 5.39144E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.05 using 59 PHA bins.
# Reduced chi-squared = 1.037 for 56 degrees of freedom
# Null hypothesis probability = 3.995280e-01
Photon flux (15-150 keV) in 32.78 sec: 0.350910 ( -0.04098 0.041075 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.09759e-06 ( -1.32116e-07 1.30274e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.464 sec. to 1.464 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.804901 ( -0.33017 0.35923 )
Norm@50keV : 1.04434E-02 ( -0.00216126 0.00211217 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.29 using 59 PHA bins.
# Reduced chi-squared = 0.9700 for 57 degrees of freedom
# Null hypothesis probability = 5.393908e-01
Photon flux (15-150 keV) in 1 sec: 1.20007 ( -0.239532 0.24095 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21801e-07 ( -2.47031e-08 2.48415e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.464 sec. to 1.464 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.248227 ( -0.841166 2.02143 )
Epeak [keV] : 189.456 ( -189.47 -189.47 )
Norm@50keV : 1.79841E-02 ( -0.00935279 0.0950933 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.86 using 59 PHA bins.
# Reduced chi-squared = 0.9797 for 56 degrees of freedom
# Null hypothesis probability = 5.180004e-01
Photon flux (15-150 keV) in 1 sec: 1.17788 ( -0.248002 0.24728 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.19391e-07 ( -2.69297e-08 2.58569e-08 ) ergs/cm2
Time-resolved spectra
