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 22.792 sec. to 111.424 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.14412 ( -0.245514 0.227071 )
Norm@50keV : 1.01565E-03 ( -0.000175342 0.000171597 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.68 using 59 bins.
Reduced chi-squared = 1.01193
# Null hypothesis probability of 4.50e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 88.63 sec: 0.163372 ( -0.019444 0.019445 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.40448e-07 ( -1.25868e-07 1.30175e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 22.792 sec. to 111.424 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.25578 ( -0.70541 1.36938 )
Epeak [keV] : 31.4925 ( -9.37503 15.6438 )
Norm@50keV : 3.58696E-03 ( -0.00358731 0.0226514 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 55.56 using 59 bins.
Reduced chi-squared = 0.992143
# Null hypothesis probability of 4.92e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 88.63 sec: 0.158870 ( -0.019907 0.02004 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.60993e-07 ( -1.34249e-07 1.55609e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 41.820 sec. to 42.820 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.66756 ( -0.546093 0.502535 )
Norm@50keV : 4.53626E-03 ( -0.0015954 0.00154077 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 45.82 using 59 bins.
Reduced chi-squared = 0.80386
# Null hypothesis probability of 8.56e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.595821 ( -0.187587 0.187722 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.2124e-08 ( -1.50252e-08 1.56045e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 41.820 sec. to 42.820 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.455432 ( -1.7488 3.21205 )
Epeak [keV] : 58.4775 ( -58.4782 -58.4782 )
Norm@50keV : 2.07820E-02 ( -0.0207811 1.05877 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 44.80 using 59 bins.
Reduced chi-squared = 0.8
# Null hypothesis probability of 8.59e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.581422 ( -0.18912 0.189239 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.904e-08 ( -1.44686e-08 1.62632e-08 ) ergs/cm2
Time-resolved spectra
