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 0.000 sec. to 0.484 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.09017 ( -0.375065 0.387221 )
Norm@50keV : 6.69761E-03 ( -0.0013904 0.00139024 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.66 using 59 PHA bins.
# Reduced chi-squared = 1.257 for 57 degrees of freedom
# Null hypothesis probability = 9.152073e-02
Photon flux (15-150 keV) in 0.484 sec: 0.776155 ( -0.163505 0.164012 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.40028e-08 ( -8.0057e-09 8.16929e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 0.484 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.3337 ( -6.39912 2.61427 )
Epeak [keV] : 109.492 ( )
Norm@50keV : 1.02724E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.72 using 59 PHA bins.
# Reduced chi-squared = 1.263 for 56 degrees of freedom
# Null hypothesis probability = 8.909796e-02
Photon flux (15-150 keV) in 0.484 sec: 0.770465 ( -0.168998 0.167866 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.3626e-08 ( -8.73484e-09 8.4336e-09 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.204 sec. to 0.784 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.07121 ( -0.557307 0.60386 )
Norm@50keV : 2.94825E-03 ( -0.000917962 0.000915558 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.82 using 59 PHA bins.
# Reduced chi-squared = 0.9617 for 57 degrees of freedom
# Null hypothesis probability = 5.573887e-01
Photon flux (15-150 keV) in 0.988 sec: 0.341087 ( -0.107911 0.108591 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.07438e-08 ( -1.05496e-08 1.08527e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.204 sec. to 0.784 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -3.01722 ( 3.0098 4.51959 )
Epeak [keV] : 275.930 ( )
Norm@50keV : 1.70135E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.76 using 59 PHA bins.
# Reduced chi-squared = 0.9779 for 56 degrees of freedom
# Null hypothesis probability = 5.217217e-01
Photon flux (15-150 keV) in 0.988 sec: 0.338852 ( -0.110578 0.109889 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.04142e-08 ( -1.15913e-08 1.10952e-08 ) ergs/cm2
Time-resolved spectra
