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 -11.364 sec. to 86.824 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.54387 ( -0.223385 0.219553 )
Norm@50keV : 7.38466E-04 ( -0.000107211 0.000106108 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.31 using 59 PHA bins.
# Reduced chi-squared = 1.181 for 57 degrees of freedom
# Null hypothesis probability = 1.648802e-01
Photon flux (15-150 keV) in 98.19 sec: 9.33237E-02 ( -0.0126509 0.0126563 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.83278e-07 ( -1.0698e-07 1.09237e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.364 sec. to 86.824 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.388512 ( -1.28711 1.91681 )
Epeak [keV] : 53.5264 ( -9.45579 24.9013 )
Norm@50keV : 8.79744E-03 ( -0.00925593 0.0985568 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.49 using 59 PHA bins.
# Reduced chi-squared = 1.062 for 56 degrees of freedom
# Null hypothesis probability = 3.498405e-01
Photon flux (15-150 keV) in 98.19 sec: 8.68828E-02 ( -0.0132516 0.0132982 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.6466e-07 ( -1.08636e-07 1.26037e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -2.296 sec. to -1.296 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.37881 ( -0.650963 0.644405 )
Norm@50keV : 2.58654E-03 ( -0.0010438 0.00103323 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.28 using 59 PHA bins.
# Reduced chi-squared = 0.7769 for 57 degrees of freedom
# Null hypothesis probability = 8.905372e-01
Photon flux (15-150 keV) in 1 sec: 0.313532 ( -0.124603 0.125255 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.51021e-08 ( -1.07878e-08 1.12752e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.296 sec. to -1.296 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.33013 ( -5.49 -4.00392 )
Epeak [keV] : 52.6669 ( -12.2332 9682.73 )
Norm@50keV : 0.676028 ( -0.64939 3152.08 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.61 using 59 PHA bins.
# Reduced chi-squared = 0.7430 for 56 degrees of freedom
# Null hypothesis probability = 9.241289e-01
Photon flux (15-150 keV) in 1 sec: 0.269911 ( -0.119308 0.134608 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.9215e-08 ( -8.89713e-09 1.23627e-08 ) ergs/cm2
Time-resolved spectra
