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 -0.008 sec. to 0.076 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.05436 ( -0.354751 0.367366 )
Norm@50keV : 1.84166E-02 ( -0.0037333 0.00372633 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.41 using 59 PHA bins.
# Reduced chi-squared = 1.077 for 57 degrees of freedom
# Null hypothesis probability = 3.209532e-01
Photon flux (15-150 keV) in 0.084 sec: 2.12775 ( -0.4389 0.43974 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.64195e-08 ( -3.68857e-09 3.71541e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.008 sec. to 0.076 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.28971 ( -1.77015 2.50374 )
Epeak [keV] : 96.6595 ( )
Norm@50keV : 3.10627E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.15 using 59 PHA bins.
# Reduced chi-squared = 1.092 for 56 degrees of freedom
# Null hypothesis probability = 2.964496e-01
Photon flux (15-150 keV) in 0.084 sec: 2.12746 ( -0.43887 0.43949 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.65097e-08 ( -4.53128e-09 3.83631e-09 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.464 sec. to 0.536 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31085 ( -0.735362 0.783998 )
Norm@50keV : 2.13700E-03 ( -0.000891004 0.00086821 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.75 using 59 PHA bins.
# Reduced chi-squared = 0.8027 for 57 degrees of freedom
# Null hypothesis probability = 8.573305e-01
Photon flux (15-150 keV) in 1 sec: 0.255468 ( -0.102525 0.102719 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.10644e-08 ( -9.55534e-09 1.01942e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.464 sec. to 0.536 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31328 ( -0.719517 1.25279 )
Epeak [keV] : 9999.26 ( -9999.36 -9999.36 )
Norm@50keV : 2.14137E-03 ( -0.00214371 -0.00214371 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.75 using 59 PHA bins.
# Reduced chi-squared = 0.8170 for 56 degrees of freedom
# Null hypothesis probability = 8.340984e-01
Photon flux (15-150 keV) in 1 sec: 0.255501 ( -0.10529 0.102613 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.11072e-08 ( -1.35827e-08 8.25307e-09 ) ergs/cm2
Time-resolved spectra
