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 0.148 sec. to 0.448 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.758586 ( -0.121921 0.124939 )
Norm@50keV : 7.84841E-02 ( -0.00567241 0.00564841 )
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#Fit statistic : Chi-Squared = 58.41 using 59 PHA bins.
# Reduced chi-squared = 1.025 for 57 degrees of freedom
# Null hypothesis probability = 4.232770e-01
Photon flux (15-150 keV) in 0.3 sec: 0.525477 ( -0.032798 0.146213 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.80079e-07 ( -2.19478e-08 2.20766e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.148 sec. to 0.448 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.415329 ( -0.440599 0.547899 )
Epeak [keV] : 266.609 ( -266.609 -266.609 )
Norm@50keV : 0.111675 ( -0.0382381 0.0808612 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.98 using 59 PHA bins.
# Reduced chi-squared = 1.018 for 56 degrees of freedom
# Null hypothesis probability = 4.382536e-01
Photon flux (15-150 keV) in 0.3 sec: 8.94465 ( -0.65503 0.6538 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.75284e-07 ( -2.42914e-08 2.33649e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.200 sec. to 0.800 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.811916 ( -0.153553 0.159445 )
Norm@50keV : 2.45799E-02 ( -0.00222394 0.00220428 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.69 using 59 PHA bins.
# Reduced chi-squared = 0.9068 for 57 degrees of freedom
# Null hypothesis probability = 6.738922e-01
Photon flux (15-150 keV) in 1 sec: 2.82388 ( -0.25007 0.2506 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.85838e-07 ( -2.64798e-08 2.66332e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.200 sec. to 0.800 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.588504 ( -0.295103 0.652056 )
Epeak [keV] : 371.959 ( -371.963 -371.963 )
Norm@50keV : 3.07523E-02 ( -0.00796558 0.0269339 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.26 using 59 PHA bins.
# Reduced chi-squared = 0.9154 for 56 degrees of freedom
# Null hypothesis probability = 6.544868e-01
Photon flux (15-150 keV) in 1 sec: 2.80094 ( -0.25692 0.25645 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.82872e-07 ( -2.823e-08 2.77842e-08 ) ergs/cm2
Time-resolved spectra
