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 -15.920 sec. to 51.168 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.90941 ( -0.0796954 0.0787018 )
Norm@50keV : 3.86718E-03 ( -0.000173676 0.000172558 )
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#Fit statistic : Chi-Squared = 57.69 using 59 PHA bins.
# Reduced chi-squared = 1.012 for 57 degrees of freedom
# Null hypothesis probability = 4.496416e-01
Photon flux (15-150 keV) in 67.09 sec: 0.557246 ( -0.023687 0.023749 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.38593e-06 ( -1.05441e-07 1.06013e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.920 sec. to 51.168 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.51932 ( -0.317317 0.343696 )
Epeak [keV] : 57.0218 ( -10.5804 46.1234 )
Norm@50keV : 6.21238E-03 ( -0.00194523 0.00315625 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.21 using 59 PHA bins.
# Reduced chi-squared = 0.9502 for 56 degrees of freedom
# Null hypothesis probability = 5.811268e-01
Photon flux (15-150 keV) in 67.09 sec: 0.542837 ( -0.026253 0.026297 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.29534e-06 ( -1.26801e-07 1.27513e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 27.824 sec. to 28.824 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.70298 ( -0.116808 0.114163 )
Norm@50keV : 2.36545E-02 ( -0.00173064 0.00171535 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.16 using 59 PHA bins.
# Reduced chi-squared = 0.9501 for 57 degrees of freedom
# Null hypothesis probability = 5.824869e-01
Photon flux (15-150 keV) in 1 sec: 3.14499 ( -0.21153 0.21164 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.18993e-07 ( -1.67516e-08 1.69027e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 27.824 sec. to 28.824 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.994779 ( -0.481162 0.541976 )
Epeak [keV] : 67.0482 ( -12.5355 43.1325 )
Norm@50keV : 5.61007E-02 ( -0.0244647 0.051373 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.52 using 59 PHA bins.
# Reduced chi-squared = 0.8485 for 56 degrees of freedom
# Null hypothesis probability = 7.829541e-01
Photon flux (15-150 keV) in 1 sec: 3.06011 ( -0.21957 0.21918 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.07778e-07 ( -1.83605e-08 1.853e-08 ) ergs/cm2
Time-resolved spectra
