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 -16.764 sec. to 58.732 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.77457 ( -0.0443759 0.0442923 )
Norm@50keV : 8.54140E-03 ( -0.000192276 0.000192213 )
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#Fit statistic : Chi-Squared = 47.67 using 59 PHA bins.
# Reduced chi-squared = 0.8363 for 57 degrees of freedom
# Null hypothesis probability = 8.059732e-01
Photon flux (15-150 keV) in 75.5 sec: 1.16564 ( -0.03065 0.0308 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.94384e-06 ( -1.35698e-07 1.35932e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -16.764 sec. to 58.732 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.60532 ( -0.172488 0.180304 )
Epeak [keV] : 123.185 ( -37.7862 7921.98 )
Norm@50keV : 1.02600E-02 ( -0.0016133 0.00215252 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.90 using 59 PHA bins.
# Reduced chi-squared = 0.8018 for 56 degrees of freedom
# Null hypothesis probability = 8.561870e-01
Photon flux (15-150 keV) in 75.5 sec: 1.14792 ( -0.03514 0.03537 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.86337e-06 ( -1.58219e-07 1.57747e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 11.216 sec. to 12.216 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.940054 ( -0.0613719 0.0617734 )
Norm@50keV : 8.36366E-02 ( -0.00287942 0.00287159 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.29 using 59 PHA bins.
# Reduced chi-squared = 0.7595 for 57 degrees of freedom
# Null hypothesis probability = 9.099384e-01
Photon flux (15-150 keV) in 1 sec: 0.479969 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 9.24485e-07 ( -3.42186e-08 3.42973e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 11.216 sec. to 12.216 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.8487 ( -0.116755 0.24112 )
Epeak [keV] : 758.910 ( -758.91 -758.91 )
Norm@50keV : 9.14666E-02 ( -0.0131089 0.0235463 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.84 using 59 PHA bins.
# Reduced chi-squared = 0.7650 for 56 degrees of freedom
# Null hypothesis probability = 9.019059e-01
Photon flux (15-150 keV) in 1 sec: 9.56870 ( -0.34598 0.3396 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.21446e-07 ( -3.52904e-08 3.48669e-08 ) ergs/cm2
Time-resolved spectra
