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 -3.812 sec. to 32.212 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.43978 ( -0.077068 0.0769673 )
Norm@50keV : 7.37970E-03 ( -0.00030614 0.00030601 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.95 using 59 PHA bins.
# Reduced chi-squared = 1.017 for 57 degrees of freedom
# Null hypothesis probability = 4.398941e-01
Photon flux (15-150 keV) in 36.02 sec: 0.907182 ( -0.040044 0.040146 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.54885e-06 ( -1.14381e-07 1.1472e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.812 sec. to 32.212 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.26608 ( -0.210551 0.313525 )
Epeak [keV] : 229.158 ( -229.154 -229.154 )
Norm@50keV : 8.89500E-03 ( -0.00173378 0.00345242 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.96 using 59 PHA bins.
# Reduced chi-squared = 1.017 for 56 degrees of freedom
# Null hypothesis probability = 4.392302e-01
Photon flux (15-150 keV) in 36.02 sec: 0.897223 ( -0.043226 0.043369 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.51984e-06 ( -1.25185e-07 1.24596e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.344 sec. to 0.656 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.10877 ( -0.114584 0.115813 )
Norm@50keV : 3.60351E-02 ( -0.00236084 0.00235861 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.71 using 59 PHA bins.
# Reduced chi-squared = 0.9599 for 57 degrees of freedom
# Null hypothesis probability = 5.613719e-01
Photon flux (15-150 keV) in 1 sec: 4.18345 ( -0.28196 0.28242 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.75751e-07 ( -2.70365e-08 2.71423e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.344 sec. to 0.656 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.10367 ( -0.17132 0.385218 )
Epeak [keV] : 9998.30 ( -9998.24 -9998.24 )
Norm@50keV : 3.62301E-02 ( -0.00236366 0.0205756 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.71 using 59 PHA bins.
# Reduced chi-squared = 0.9770 for 56 degrees of freedom
# Null hypothesis probability = 5.238146e-01
Photon flux (15-150 keV) in 1 sec: 4.18062 ( -0.28135 0.28493 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.75708e-07 ( -2.82439e-08 2.61938e-08 ) ergs/cm2
Time-resolved spectra
