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 -6.520 sec. to 54.128 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.28654 ( -0.0381907 0.0382842 )
Norm@50keV : 2.07190E-02 ( -0.000419367 0.000418838 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.72 using 59 PHA bins.
# Reduced chi-squared = 0.8547 for 57 degrees of freedom
# Null hypothesis probability = 7.744700e-01
Photon flux (15-150 keV) in 60.65 sec: 2.46583 ( -0.05557 0.05573 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.24604e-05 ( -2.56681e-07 2.56819e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.520 sec. to 54.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.1663 ( -0.123463 0.155335 )
Epeak [keV] : 414.106 ( -197.924 -414.106 )
Norm@50keV : 2.32831E-02 ( -0.0027235 0.00368067 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.87 using 59 PHA bins.
# Reduced chi-squared = 0.8370 for 56 degrees of freedom
# Null hypothesis probability = 8.024540e-01
Photon flux (15-150 keV) in 60.65 sec: 2.44312 ( -0.06176 0.06203 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.23849e-05 ( -2.73829e-07 2.73315e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.864 sec. to 5.864 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.10251 ( -0.0503219 0.0504505 )
Norm@50keV : 0.259034 ( -0.00741892 0.00741594 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.37 using 59 PHA bins.
# Reduced chi-squared = 1.112 for 57 degrees of freedom
# Null hypothesis probability = 2.619619e-01
Photon flux (15-150 keV) in 1 sec: 1.16024 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.70639e-06 ( -8.41647e-08 8.42897e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.864 sec. to 5.864 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.758025 ( -0.201403 0.210817 )
Epeak [keV] : 210.390 ( -57.869 199.937 )
Norm@50keV : 0.366799 ( -0.0659268 0.0842303 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.58 using 59 PHA bins.
# Reduced chi-squared = 0.9747 for 56 degrees of freedom
# Null hypothesis probability = 5.287088e-01
Photon flux (15-150 keV) in 1 sec: 29.5863 ( -0.9258 0.9269 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.66876e-06 ( -8.83424e-08 8.80701e-08 ) ergs/cm2
Time-resolved spectra
