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 -0.864 sec. to 5.012 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.85879 ( -0.182257 0.173682 )
Norm@50keV : 4.53612E-03 ( -0.000555106 0.000545827 )
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#Fit statistic : Chi-Squared = 87.71 using 59 PHA bins.
# Reduced chi-squared = 1.539 for 57 degrees of freedom
# Null hypothesis probability = 5.559035e-03
Photon flux (15-150 keV) in 5.876 sec: 0.639925 ( -0.062785 0.062785 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.45099e-07 ( -2.95969e-08 3.03122e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.864 sec. to 5.012 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.63779 ( -0.779242 0.955678 )
Epeak [keV] : 46.5334 ( -8.10926 15.5559 )
Norm@50keV : 2.28581E-02 ( -0.0145744 0.0595655 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 79.85 using 59 PHA bins.
# Reduced chi-squared = 1.426 for 56 degrees of freedom
# Null hypothesis probability = 1.987724e-02
Photon flux (15-150 keV) in 5.876 sec: 0.612740 ( -0.064017 0.064339 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.17782e-07 ( -3.03424e-08 3.29337e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.612 sec. to 1.612 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.64607 ( -0.244939 0.236566 )
Norm@50keV : 7.72695E-03 ( -0.00129603 0.00127831 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.33 using 59 PHA bins.
# Reduced chi-squared = 1.322 for 57 degrees of freedom
# Null hypothesis probability = 5.242713e-02
Photon flux (15-150 keV) in 1 sec: 1.00768 ( -0.150367 0.15037 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.19118e-08 ( -1.26466e-08 1.29965e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.612 sec. to 1.612 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.324333 ( -1.21814 1.73198 )
Epeak [keV] : 49.9851 ( -8.95647 18.6769 )
Norm@50keV : 0.102287 ( -0.102599 0.945403 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.31 using 59 PHA bins.
# Reduced chi-squared = 1.184 for 56 degrees of freedom
# Null hypothesis probability = 1.630520e-01
Photon flux (15-150 keV) in 1 sec: 0.956325 ( -0.15 0.151105 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.07337e-08 ( -1.18088e-08 1.34127e-08 ) ergs/cm2
Time-resolved spectra
