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 0.280 sec. to 5.064 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.50906 ( -0.394653 0.33506 )
Norm@50keV : 7.76598E-03 ( -0.00216841 0.00210312 )
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#Fit statistic : Chi-Squared = 54.34 using 59 PHA bins.
# Reduced chi-squared = 0.9533 for 57 degrees of freedom
# Null hypothesis probability = 5.755166e-01
Photon flux (15-150 keV) in 4.784 sec: 1.53431 ( -0.26393 0.26394 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.72513e-07 ( -7.62608e-08 7.87829e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.280 sec. to 5.064 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.49334 ( -0.508637 1.9391 )
Epeak [keV] : 18.9910 ( )
Norm@50keV : 3.25989E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.03 using 59 PHA bins.
# Reduced chi-squared = 0.9470 for 56 degrees of freedom
# Null hypothesis probability = 5.879339e-01
Photon flux (15-150 keV) in 4.784 sec: 1.50360 ( -0.26636 0.26146 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.828 sec. to 1.828 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.98879 ( -0.444753 0.401971 )
Norm@50keV : 1.36839E-02 ( -0.00393964 0.0038217 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.02 using 59 PHA bins.
# Reduced chi-squared = 1.018 for 57 degrees of freedom
# Null hypothesis probability = 4.373036e-01
Photon flux (15-150 keV) in 1 sec: 2.04220 ( -0.54003 0.54287 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26145e-07 ( -3.44111e-08 3.48232e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.828 sec. to 1.828 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.17891 ( -2.35477 4.79805 )
Epeak [keV] : 45.0711 ( -27.8136 -45.0135 )
Norm@50keV : 0.207066 ( -0.218375 116.566 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.65 using 59 PHA bins.
# Reduced chi-squared = 0.9938 for 56 degrees of freedom
# Null hypothesis probability = 4.879118e-01
Photon flux (15-150 keV) in 1 sec: 1.91070 ( -0.56922 0.5702 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.13849e-07 ( -3.50828e-08 3.77583e-08 ) ergs/cm2
Time-resolved spectra
