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 -130.128 sec. to 108.912 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.33513 ( -0.0563251 0.0565238 )
Norm@50keV : 4.00113E-03 ( -0.000121131 0.000121108 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.91 using 59 PHA bins.
# Reduced chi-squared = 0.8406 for 57 degrees of freedom
# Null hypothesis probability = 7.988438e-01
Photon flux (15-150 keV) in 239 sec: 0.480579 ( -0.015794 0.015832 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.37234e-06 ( -3.01697e-07 3.02371e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -130.128 sec. to 108.912 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.16323 ( -0.192917 0.227854 )
Epeak [keV] : 271.043 ( )
Norm@50keV : 4.79022E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.09 using 59 PHA bins.
# Reduced chi-squared = 0.8231 for 56 degrees of freedom
# Null hypothesis probability = 8.247693e-01
Photon flux (15-150 keV) in 239 sec: 0.475304 ( -0.017052 0.017088 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.27189e-06 ( -3.2879e-07 3.27377e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 44.188 sec. to 45.188 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.19415 ( -0.186939 0.189737 )
Norm@50keV : 1.83307E-02 ( -0.00205655 0.00205563 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.77 using 59 PHA bins.
# Reduced chi-squared = 1.242 for 57 degrees of freedom
# Null hypothesis probability = 1.038299e-01
Photon flux (15-150 keV) in 1 sec: 2.14990 ( -0.24506 0.24527 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.86303e-07 ( -2.33997e-08 2.35717e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 44.188 sec. to 45.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.980168 ( -0.381142 0.879447 )
Epeak [keV] : 244.568 ( -245.133 -245.133 )
Norm@50keV : 2.35053E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.54 using 59 PHA bins.
# Reduced chi-squared = 1.260 for 56 degrees of freedom
# Null hypothesis probability = 9.142197e-02
Photon flux (15-150 keV) in 1 sec: 2.13794 ( -0.24928 0.24872 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.83565e-07 ( -2.62428e-08 2.5254e-08 ) ergs/cm2
Time-resolved spectra
