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 -21.592 sec. to 146.260 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.33404 ( -0.106659 0.107874 )
Norm@50keV : 2.21459E-03 ( -0.000138819 0.000138817 )
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#Fit statistic : Chi-Squared = 74.31 using 59 PHA bins.
# Reduced chi-squared = 1.304 for 57 degrees of freedom
# Null hypothesis probability = 6.152562e-02
Photon flux (15-150 keV) in 167.9 sec: 0.265938 ( -0.017658 0.017704 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.64519e-06 ( -2.43692e-07 2.44728e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -21.592 sec. to 146.260 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.773957 ( -0.473002 0.538568 )
Epeak [keV] : 113.058 ( -32.4879 288.862 )
Norm@50keV : 4.17757E-03 ( -0.00170479 0.00341446 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.18 using 59 PHA bins.
# Reduced chi-squared = 1.253 for 56 degrees of freedom
# Null hypothesis probability = 9.628554e-02
Photon flux (15-150 keV) in 167.9 sec: 0.259725 ( -0.018479 0.018475 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.50495e-06 ( -2.78751e-07 2.74783e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.872 sec. to 2.872 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.807232 ( -0.357724 0.394984 )
Norm@50keV : 1.06097E-02 ( -0.00254252 0.00245108 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 83.16 using 59 PHA bins.
# Reduced chi-squared = 1.459 for 57 degrees of freedom
# Null hypothesis probability = 1.347755e-02
Photon flux (15-150 keV) in 1 sec: 1.21907 ( -0.275909 0.28129 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.23623e-07 ( -2.5825e-08 2.58387e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.872 sec. to 2.872 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.07846 ( -2.0185 5.42104 )
Epeak [keV] : 113.582 ( -32.8191 -113.265 )
Norm@50keV : 4.72059E-02 ( -0.0478517 1.61382 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 81.13 using 59 PHA bins.
# Reduced chi-squared = 1.449 for 56 degrees of freedom
# Null hypothesis probability = 1.570168e-02
Photon flux (15-150 keV) in 1 sec: 1.10328 ( -0.312814 0.31712 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.19812e-07 ( -2.84974e-08 2.71178e-08 ) ergs/cm2
Time-resolved spectra
