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 -7.940 sec. to 3.772 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.88697 ( -0.135232 0.131264 )
Norm@50keV : 4.56756E-03 ( -0.000388535 0.000383116 )
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#Fit statistic : Chi-Squared = 49.71 using 59 PHA bins.
# Reduced chi-squared = 0.8722 for 57 degrees of freedom
# Null hypothesis probability = 7.424069e-01
Photon flux (15-150 keV) in 11.71 sec: 0.651936 ( -0.046876 0.046904 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.91776e-07 ( -4.10969e-08 4.16662e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -7.940 sec. to 3.772 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29384 ( -0.542652 0.624436 )
Epeak [keV] : 51.6540 ( -11.3913 73.7335 )
Norm@50keV : 9.81822E-03 ( -0.00486011 0.0120564 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.19 using 59 PHA bins.
# Reduced chi-squared = 0.8249 for 56 degrees of freedom
# Null hypothesis probability = 8.219657e-01
Photon flux (15-150 keV) in 11.71 sec: 0.634781 ( -0.049339 0.049343 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.62964e-07 ( -4.73151e-08 4.86551e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.736 sec. to 2.736 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.35791 ( -0.195974 0.195977 )
Norm@50keV : 1.13097E-02 ( -0.00131682 0.00131204 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.84 using 59 PHA bins.
# Reduced chi-squared = 0.7866 for 57 degrees of freedom
# Null hypothesis probability = 8.786311e-01
Photon flux (15-150 keV) in 1 sec: 1.36475 ( -0.15813 0.15829 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10278e-07 ( -1.43556e-08 1.45236e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.736 sec. to 2.736 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.946622 ( -0.512143 0.900917 )
Epeak [keV] : 126.855 ( -60.5327 -126.875 )
Norm@50keV : 1.83879E-02 ( -0.00813626 0.0337032 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.00 using 59 PHA bins.
# Reduced chi-squared = 0.7857 for 56 degrees of freedom
# Null hypothesis probability = 8.774929e-01
Photon flux (15-150 keV) in 1 sec: 1.34379 ( -0.16357 0.16305 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06574e-07 ( -1.62091e-08 1.60428e-08 ) ergs/cm2
Time-resolved spectra
