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 -2.304 sec. to 10.440 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.05122 ( -0.128081 0.123778 )
Norm@50keV : 5.70256E-03 ( -0.000466089 0.000459432 )
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#Fit statistic : Chi-Squared = 71.57 using 59 PHA bins.
# Reduced chi-squared = 1.256 for 57 degrees of freedom
# Null hypothesis probability = 9.262713e-02
Photon flux (15-150 keV) in 12.74 sec: 0.876233 ( -0.058498 0.058554 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.72295e-07 ( -5.07258e-08 5.13065e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.304 sec. to 10.440 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.37045 ( -0.56947 0.66924 )
Epeak [keV] : 38.9931 ( -21.8899 11.3221 )
Norm@50keV : 1.39243E-02 ( -0.00724119 0.0196343 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.35 using 59 PHA bins.
# Reduced chi-squared = 1.203 for 56 degrees of freedom
# Null hypothesis probability = 1.424311e-01
Photon flux (15-150 keV) in 12.74 sec: 0.849622 ( -0.062589 0.062476 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.2923e-07 ( -5.98011e-08 6.17405e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.112 sec. to 0.888 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.81239 ( -0.192153 0.184142 )
Norm@50keV : 1.36239E-02 ( -0.00167932 0.00164899 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.13 using 59 PHA bins.
# Reduced chi-squared = 1.002 for 57 degrees of freedom
# Null hypothesis probability = 4.704181e-01
Photon flux (15-150 keV) in 1 sec: 1.88654 ( -0.20517 0.20528 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25392e-07 ( -1.5542e-08 1.5722e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.112 sec. to 0.888 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.24747 ( -0.684187 0.907713 )
Epeak [keV] : 60.5585 ( -14.3212 -60.5585 )
Norm@50keV : 2.78122E-02 ( -0.015193 0.0595857 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.50 using 59 PHA bins.
# Reduced chi-squared = 0.9911 for 56 degrees of freedom
# Null hypothesis probability = 4.936807e-01
Photon flux (15-150 keV) in 1 sec: 1.85338 ( -0.21066 0.21006 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.20127e-07 ( -1.70599e-08 1.72266e-08 ) ergs/cm2
Time-resolved spectra
