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 -39.372 sec. to 30.248 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.71289 ( -0.114494 0.11251 )
Norm@50keV : 2.68875E-03 ( -0.000182443 0.000180759 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.03 using 59 PHA bins.
# Reduced chi-squared = 0.7900 for 57 degrees of freedom
# Null hypothesis probability = 8.742984e-01
Photon flux (15-150 keV) in 69.62 sec: 0.358734 ( -0.022183 0.022202 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.73171e-06 ( -1.23048e-07 1.24404e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -39.372 sec. to 30.248 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29883 ( -0.440629 0.495599 )
Epeak [keV] : 77.6052 ( -21.3341 -77.6052 )
Norm@50keV : 4.49068E-03 ( -0.00184179 0.00374889 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.47 using 59 PHA bins.
# Reduced chi-squared = 0.7585 for 56 degrees of freedom
# Null hypothesis probability = 9.089224e-01
Photon flux (15-150 keV) in 69.62 sec: 0.351080 ( -0.0236 0.023588 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.65872e-06 ( -1.44661e-07 1.45722e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -19.572 sec. to -18.572 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.25175 ( -0.294277 0.302843 )
Norm@50keV : 8.12887E-03 ( -0.00143247 0.00143195 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.94 using 59 PHA bins.
# Reduced chi-squared = 0.8761 for 57 degrees of freedom
# Null hypothesis probability = 7.348818e-01
Photon flux (15-150 keV) in 1 sec: 0.961707 ( -0.174208 0.174663 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.13242e-08 ( -1.5684e-08 1.58453e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -19.572 sec. to -18.572 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.854801 ( -1.18983 1.47672 )
Epeak [keV] : 149.098 ( -149.167 -149.167 )
Norm@50keV : 1.28105E-02 ( -0.00596966 0.0549788 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.60 using 59 PHA bins.
# Reduced chi-squared = 0.8856 for 56 degrees of freedom
# Null hypothesis probability = 7.143947e-01
Photon flux (15-150 keV) in 1 sec: 0.949796 ( -0.178585 0.178094 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.92228e-08 ( -1.74368e-08 1.69406e-08 ) ergs/cm2
Time-resolved spectra
