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 -11.196 sec. to 18.008 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.55037 ( -0.197043 0.191828 )
Norm@50keV : 1.79729E-03 ( -0.000234263 0.000231611 )
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#Fit statistic : Chi-Squared = 58.61 using 59 PHA bins.
# Reduced chi-squared = 1.028 for 57 degrees of freedom
# Null hypothesis probability = 4.161632e-01
Photon flux (15-150 keV) in 29.2 sec: 0.227557 ( -0.026891 0.026892 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.94108e-07 ( -6.98079e-08 7.13925e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.196 sec. to 18.008 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.184135 ( -0.970846 1.2386 )
Epeak [keV] : 56.1921 ( -9.20013 19.1067 )
Norm@50keV : 1.60119E-02 ( -0.0160121 0.0590128 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.70 using 59 PHA bins.
# Reduced chi-squared = 0.8518 for 56 degrees of freedom
# Null hypothesis probability = 7.772946e-01
Photon flux (15-150 keV) in 29.2 sec: 0.214686 ( -0.027334 0.027481 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.24866e-07 ( -6.8281e-08 7.52986e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.864 sec. to 2.864 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.681 ( -0.454853 0.408398 )
Norm@50keV : 4.44692E-03 ( -0.00131783 0.00126382 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.95 using 59 PHA bins.
# Reduced chi-squared = 0.7886 for 57 degrees of freedom
# Null hypothesis probability = 8.761726e-01
Photon flux (15-150 keV) in 1 sec: 0.586758 ( -0.143111 0.143155 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.12449e-08 ( -1.23966e-08 1.30901e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.864 sec. to 2.864 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.578199 ( -1.55919 2.21404 )
Epeak [keV] : 57.3271 ( -57.3387 -57.3387 )
Norm@50keV : 1.82387E-02 ( -0.0182256 0.295304 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.62 using 59 PHA bins.
# Reduced chi-squared = 0.7789 for 56 degrees of freedom
# Null hypothesis probability = 8.859190e-01
Photon flux (15-150 keV) in 1 sec: 0.569669 ( -0.142647 0.144377 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.76929e-08 ( -1.20085e-08 1.38406e-08 ) ergs/cm2
Time-resolved spectra
