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 -2.784 sec. to 17.152 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.86877 ( -0.210921 0.201759 )
Norm@50keV : 5.85021E-03 ( -0.000813261 0.000799855 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.89 using 59 PHA bins.
# Reduced chi-squared = 1.209 for 57 degrees of freedom
# Null hypothesis probability = 1.344039e-01
Photon flux (15-150 keV) in 19.94 sec: 0.828698 ( -0.102284 0.102405 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.07262e-06 ( -1.47164e-07 1.49111e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.784 sec. to 17.152 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.355513 ( -1.04264 1.35509 )
Epeak [keV] : 47.9571 ( -8.32925 16.3744 )
Norm@50keV : 4.01682E-02 ( -0.0401692 0.186362 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.20 using 59 PHA bins.
# Reduced chi-squared = 1.111 for 56 degrees of freedom
# Null hypothesis probability = 2.649671e-01
Photon flux (15-150 keV) in 19.94 sec: 0.789239 ( -0.105778 0.105911 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.66619e-07 ( -1.49764e-07 1.60384e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.420 sec. to 1.420 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.72458 ( -0.514016 0.50131 )
Norm@50keV : 9.32168E-03 ( -0.00313968 0.00310209 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.91 using 59 PHA bins.
# Reduced chi-squared = 1.209 for 57 degrees of freedom
# Null hypothesis probability = 1.339954e-01
Photon flux (15-150 keV) in 1 sec: 1.24879 ( -0.418702 0.42231 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.61747e-08 ( -2.93339e-08 2.97698e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.420 sec. to 1.420 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.24437 ( -2.94186 6.20315 )
Epeak [keV] : 50.2748 ( -12.5389 59.8914 )
Norm@50keV : 0.354045 ( -0.466591 225.446 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.64 using 59 PHA bins.
# Reduced chi-squared = 1.172 for 56 degrees of freedom
# Null hypothesis probability = 1.773120e-01
Photon flux (15-150 keV) in 1 sec: 1.15371 ( -0.435607 0.43604 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.51623e-08 ( -2.57085e-08 2.93097e-08 ) ergs/cm2
Time-resolved spectra
