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 -3.896 sec. to 3.068 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.41049 ( -0.0847294 0.0849033 )
Norm@50keV : 1.80959E-02 ( -0.000922653 0.000922652 )
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#Fit statistic : Chi-Squared = 55.63 using 59 PHA bins.
# Reduced chi-squared = 0.9760 for 57 degrees of freedom
# Null hypothesis probability = 5.264888e-01
Photon flux (15-150 keV) in 6.964 sec: 2.20909 ( -0.12045 0.12073 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21526e-06 ( -6.52309e-08 6.53852e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.896 sec. to 3.068 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.693617 ( -0.369504 0.403418 )
Epeak [keV] : 100.174 ( -18.1893 47.8201 )
Norm@50keV : 3.90350E-02 ( -0.012499 0.0203288 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.84 using 59 PHA bins.
# Reduced chi-squared = 0.7829 for 56 degrees of freedom
# Null hypothesis probability = 8.810508e-01
Photon flux (15-150 keV) in 6.964 sec: 2.14080 ( -0.12502 0.12539 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.18007e-06 ( -6.89307e-08 6.87462e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.096 sec. to 0.904 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31272 ( -0.096371 0.0964218 )
Norm@50keV : 4.87874E-02 ( -0.00301808 0.003018 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 78.42 using 59 PHA bins.
# Reduced chi-squared = 1.376 for 57 degrees of freedom
# Null hypothesis probability = 3.149402e-02
Photon flux (15-150 keV) in 1 sec: 5.83441 ( -0.37403 0.37452 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.80684e-07 ( -3.18559e-08 3.19531e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.096 sec. to 0.904 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.281032 ( -0.437056 0.48531 )
Epeak [keV] : 91.0542 ( -13.8988 28.1522 )
Norm@50keV : 0.149767 ( -0.0554464 0.0997169 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.06 using 59 PHA bins.
# Reduced chi-squared = 1.073 for 56 degrees of freedom
# Null hypothesis probability = 3.307577e-01
Photon flux (15-150 keV) in 1 sec: 5.67960 ( -0.37903 0.37963 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.65532e-07 ( -3.35059e-08 3.34444e-08 ) ergs/cm2
Time-resolved spectra
