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 70.400 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.63632 ( -0.337747 0.31727 )
Norm@50keV : 6.62027E-04 ( -0.000126631 0.000121257 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.32 using 59 PHA bins.
# Reduced chi-squared = 0.9179 for 57 degrees of freedom
# Null hypothesis probability = 6.508768e-01
Photon flux (15-150 keV) in 70.4 sec: 8.60618E-02 ( -0.0142105 0.0142192 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.34133e-07 ( -8.76494e-08 8.96875e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 70.400 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.10125 ( -0.337116 1.09731 )
Epeak [keV] : 39.7763 ( )
Norm@50keV : 3.78471E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.68 using 59 PHA bins.
# Reduced chi-squared = 0.9229 for 56 degrees of freedom
# Null hypothesis probability = 6.389341e-01
Photon flux (15-150 keV) in 70.4 sec: 8.62233E-02 ( -0.01449 0.0141697 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.36549e-07 ( -7.76744e-08 8.71629e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 14.700 sec. to 15.700 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.5 ( 1.5 1.5 )
Norm@50keV : 0.0 ( 0 0.000904021 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 43.79 using 59 PHA bins.
# Reduced chi-squared = 0.7682 for 57 degrees of freedom
# Null hypothesis probability = 9.006018e-01
Photon flux (15-150 keV) in 1 sec: 5.17812E-02 ( -0.0517812 0.104501 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.83333e-09 ( 1 5.47083e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 14.700 sec. to 15.700 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 9.14649 ( 1 1 )
Epeak [keV] : 18.2868 ( -80 -80 )
Norm@50keV : 5.93168E+06 ( -8.51613e+06 -8.51613e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.97 using 59 PHA bins.
# Reduced chi-squared = 0.7494 for 56 degrees of freedom
# Null hypothesis probability = 9.180597e-01
Photon flux (15-150 keV) in 1 sec: 7.16595E-02 ( -0.0716595 0.103767 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
