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 -10.432 sec. to 16.176 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.62959 ( -0.0650154 0.0647583 )
Norm@50keV : 4.96319E-02 ( -0.00186147 0.00186076 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.91 using 59 PHA bins.
# Reduced chi-squared = 1.314 for 57 degrees of freedom
# Null hypothesis probability = 5.599662e-02
Photon flux (15-150 keV) in 26.61 sec: 6.43801 ( -0.26319 0.264 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2311e-05 ( -4.78309e-07 4.78796e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -10.432 sec. to 16.176 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.992416 ( -0.277909 0.296062 )
Epeak [keV] : 84.9884 ( -11.8793 25.2435 )
Norm@50keV : 9.91097E-02 ( -0.0252581 0.0365017 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.41 using 59 PHA bins.
# Reduced chi-squared = 1.043 for 56 degrees of freedom
# Null hypothesis probability = 3.869927e-01
Photon flux (15-150 keV) in 26.61 sec: 6.19589 ( -0.27966 0.28085 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.19145e-05 ( -5.13943e-07 5.12777e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.596 sec. to 1.596 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.41128 ( -0.144585 0.142398 )
Norm@50keV : 0.133474 ( -0.0123802 0.0123628 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.27 using 59 PHA bins.
# Reduced chi-squared = 1.250 for 57 degrees of freedom
# Null hypothesis probability = 9.679020e-02
Photon flux (15-150 keV) in 1 sec: 0.329948 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28695e-06 ( -1.29106e-07 1.29496e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.596 sec. to 1.596 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.581363 ( -0.599014 0.693857 )
Epeak [keV] : 91.9278 ( -21.5056 95.2032 )
Norm@50keV : 0.335973 ( -0.160584 0.37792 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.41 using 59 PHA bins.
# Reduced chi-squared = 1.168 for 56 degrees of freedom
# Null hypothesis probability = 1.824458e-01
Photon flux (15-150 keV) in 1 sec: 16.0037 ( -1.549 1.5506 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25849e-06 ( -1.36291e-07 1.3518e-07 ) ergs/cm2
Time-resolved spectra
