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 -11.004 sec. to 19.776 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.22283 ( -0.131331 0.133735 )
Norm@50keV : 3.60044E-03 ( -0.000276069 0.000275668 )
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#Fit statistic : Chi-Squared = 59.15 using 59 PHA bins.
# Reduced chi-squared = 1.038 for 57 degrees of freedom
# Null hypothesis probability = 3.970539e-01
Photon flux (15-150 keV) in 30.78 sec: 0.424024 ( -0.034587 0.034758 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.11735e-06 ( -8.91927e-08 8.96003e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.004 sec. to 19.776 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.365091 ( -0.583959 0.681221 )
Epeak [keV] : 108.100 ( -24.8635 103.261 )
Norm@50keV : 8.66375E-03 ( -0.0038202 0.00815744 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.47 using 59 PHA bins.
# Reduced chi-squared = 0.9370 for 56 degrees of freedom
# Null hypothesis probability = 6.092783e-01
Photon flux (15-150 keV) in 30.78 sec: 0.404632 ( -0.036915 0.037033 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06831e-06 ( -9.68216e-08 9.65341e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.860 sec. to 3.860 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.39693 ( -0.408759 0.414464 )
Norm@50keV : 6.01987E-03 ( -0.00147531 0.00147376 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.10 using 59 PHA bins.
# Reduced chi-squared = 0.7035 for 57 degrees of freedom
# Null hypothesis probability = 9.563336e-01
Photon flux (15-150 keV) in 1 sec: 0.732594 ( -0.18805 0.19013 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.8213e-08 ( -1.5068e-08 1.5257e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.860 sec. to 3.860 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.0286136 ( -1.06336 2.97618 )
Epeak [keV] : 78.0906 ( -23.618 -78.0907 )
Norm@50keV : 2.59965E-02 ( -0.0259964 0.473637 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.44 using 59 PHA bins.
# Reduced chi-squared = 0.6864 for 56 degrees of freedom
# Null hypothesis probability = 9.647816e-01
Photon flux (15-150 keV) in 1 sec: 0.685264 ( -0.199732 0.201052 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.43488e-08 ( -1.57717e-08 1.62228e-08 ) ergs/cm2
Time-resolved spectra
