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 -67.164 sec. to 18.112 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.52478 ( -0.192707 0.189501 )
Norm@50keV : 8.82766E-04 ( -0.000102599 0.000101482 )
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#Fit statistic : Chi-Squared = 80.72 using 59 PHA bins.
# Reduced chi-squared = 1.416 for 57 degrees of freedom
# Null hypothesis probability = 2.105907e-02
Photon flux (15-150 keV) in 85.28 sec: 0.110958 ( -0.0120734 0.012079 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.11454e-07 ( -9.06467e-08 9.22704e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -67.164 sec. to 18.112 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.875526 ( -0.767937 0.964393 )
Epeak [keV] : 79.4508 ( -25.2729 -79.449 )
Norm@50keV : 1.97858E-03 ( -0.00114905 0.00456559 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 78.79 using 59 PHA bins.
# Reduced chi-squared = 1.407 for 56 degrees of freedom
# Null hypothesis probability = 2.404245e-02
Photon flux (15-150 keV) in 85.28 sec: 0.107750 ( -0.0127047 0.012681 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.63281e-07 ( -1.05816e-07 1.08897e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.120 sec. to 3.120 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.850847 ( -0.404766 0.449549 )
Norm@50keV : 4.13155E-03 ( -0.00100436 0.000973977 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.09 using 59 PHA bins.
# Reduced chi-squared = 0.9139 for 57 degrees of freedom
# Null hypothesis probability = 6.593130e-01
Photon flux (15-150 keV) in 1 sec: 0.474258 ( -0.11156 0.112339 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.72835e-08 ( -1.1393e-08 1.14857e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.120 sec. to 3.120 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.681656 ( 0.682187 2.65112 )
Epeak [keV] : 461.770 ( -463.59 -463.59 )
Norm@50keV : 4.88959E-03 ( -0.0016695 0.0522334 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.07 using 59 PHA bins.
# Reduced chi-squared = 0.9298 for 56 degrees of freedom
# Null hypothesis probability = 6.244134e-01
Photon flux (15-150 keV) in 1 sec: 0.471189 ( -0.118223 0.111025 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.69364e-08 ( -1.26201e-08 1.14888e-08 ) ergs/cm2
Time-resolved spectra
