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 -3.964 sec. to 252.992 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.45494 ( -0.03739 0.0375241 )
Norm@50keV : 5.29043E-03 ( -0.000101425 0.000101333 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.07 using 59 PHA bins.
# Reduced chi-squared = 0.6504 for 57 degrees of freedom
# Null hypothesis probability = 9.811693e-01
Photon flux (15-150 keV) in 257 sec: 0.652789 ( -0.014775 0.014838 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.30006e-05 ( -2.49929e-07 2.50229e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.964 sec. to 252.992 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.42022 ( -0.0379885 0.148731 )
Epeak [keV] : 981.144 ( -9998.79 -9998.79 )
Norm@50keV : 5.47505E-03 ( -0.000100331 0.000784002 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 37.23 using 59 PHA bins.
# Reduced chi-squared = 0.6647 for 56 degrees of freedom
# Null hypothesis probability = 9.748962e-01
Photon flux (15-150 keV) in 257 sec: 0.652679 ( -0.008527 0.014645 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.29991e-05 ( -2.53403e-07 2.47475e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 70.284 sec. to 71.284 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.27881 ( -0.0650816 0.0651605 )
Norm@50keV : 4.88687E-02 ( -0.00176993 0.00176991 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.08 using 59 PHA bins.
# Reduced chi-squared = 1.037 for 57 degrees of freedom
# Null hypothesis probability = 3.993596e-01
Photon flux (15-150 keV) in 1 sec: 5.80808 ( -0.21919 0.21947 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.85512e-07 ( -1.9411e-08 1.94631e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 70.284 sec. to 71.284 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.923964 ( -0.255676 0.27143 )
Epeak [keV] : 165.394 ( -48.9833 257.163 )
Norm@50keV : 7.15007E-02 ( -0.016732 0.0233867 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.34 using 59 PHA bins.
# Reduced chi-squared = 0.9525 for 56 degrees of freedom
# Null hypothesis probability = 5.762663e-01
Photon flux (15-150 keV) in 1 sec: 5.69971 ( -0.2316 0.23183 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.74701e-07 ( -2.11668e-08 2.10687e-08 ) ergs/cm2
Time-resolved spectra
