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 -0.216 sec. to 3.104 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.07321 ( -0.0899988 0.0909707 )
Norm@50keV : 1.96759E-02 ( -0.000995582 0.00099443 )
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#Fit statistic : Chi-Squared = 56.46 using 59 PHA bins.
# Reduced chi-squared = 0.9905 for 57 degrees of freedom
# Null hypothesis probability = 4.952590e-01
Photon flux (15-150 keV) in 3.32 sec: 2.27672 ( -0.11827 0.11842 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.89013e-07 ( -3.82869e-08 3.84287e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.216 sec. to 3.104 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.841266 ( -0.270594 0.365882 )
Epeak [keV] : 282.469 ( -282.469 -282.469 )
Norm@50keV : 2.50506E-02 ( -0.00596744 0.0111194 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.10 using 59 PHA bins.
# Reduced chi-squared = 0.9839 for 56 degrees of freedom
# Null hypothesis probability = 5.089405e-01
Photon flux (15-150 keV) in 3.32 sec: 2.25247 ( -0.12346 0.12339 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.80125e-07 ( -4.08938e-08 4.06637e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.368 sec. to 2.368 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.805855 ( -0.118801 0.121423 )
Norm@50keV : 2.99534E-02 ( -0.00204729 0.00203469 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 38.47 using 59 PHA bins.
# Reduced chi-squared = 0.6749 for 57 degrees of freedom
# Null hypothesis probability = 9.716330e-01
Photon flux (15-150 keV) in 1 sec: 3.44189 ( -0.23062 0.23092 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.49213e-07 ( -2.49257e-08 2.50268e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.368 sec. to 2.368 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.571857 ( -0.339077 0.505969 )
Epeak [keV] : 375.703 ( -375.703 -375.703 )
Norm@50keV : 3.74240E-02 ( -0.00894768 0.0217847 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.71 using 59 PHA bins.
# Reduced chi-squared = 0.6735 for 56 degrees of freedom
# Null hypothesis probability = 9.711313e-01
Photon flux (15-150 keV) in 1 sec: 3.40940 ( -0.23931 0.23908 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.4641e-07 ( -2.5879e-08 2.57503e-08 ) ergs/cm2
Time-resolved spectra
