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 -42.748 sec. to 40.016 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.56169 ( -0.0829011 0.0825818 )
Norm@50keV : 3.56604E-03 ( -0.00016649 0.000166043 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.74 using 59 PHA bins.
# Reduced chi-squared = 1.066 for 57 degrees of freedom
# Null hypothesis probability = 3.428718e-01
Photon flux (15-150 keV) in 82.76 sec: 0.452996 ( -0.021228 0.021258 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.77416e-06 ( -1.40128e-07 1.40924e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -42.748 sec. to 40.016 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.2949 ( -0.299545 0.350133 )
Epeak [keV] : 129.045 ( -47.6825 -129.063 )
Norm@50keV : 4.88612E-03 ( -0.00139982 0.00243821 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.78 using 59 PHA bins.
# Reduced chi-squared = 1.050 for 56 degrees of freedom
# Null hypothesis probability = 3.740161e-01
Photon flux (15-150 keV) in 82.76 sec: 0.446408 ( -0.022668 0.022655 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.70614e-06 ( -1.63472e-07 1.62657e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -4.688 sec. to -3.688 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.39779 ( -0.234916 0.233809 )
Norm@50keV : 9.93605E-03 ( -0.00148986 0.00148416 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.30 using 59 PHA bins.
# Reduced chi-squared = 1.058 for 57 degrees of freedom
# Null hypothesis probability = 3.573148e-01
Photon flux (15-150 keV) in 1 sec: 1.20945 ( -0.18012 0.1804 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.60616e-08 ( -1.5746e-08 1.59673e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.688 sec. to -3.688 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.185928 ( -1.09753 1.42173 )
Epeak [keV] : 68.5343 ( -14.0274 45.1198 )
Norm@50keV : 6.26211E-02 ( -0.0626208 0.243531 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.67 using 59 PHA bins.
# Reduced chi-squared = 0.9583 for 56 degrees of freedom
# Null hypothesis probability = 5.636667e-01
Photon flux (15-150 keV) in 1 sec: 1.14607 ( -0.184913 0.18555 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.6812e-08 ( -1.59522e-08 1.68573e-08 ) ergs/cm2
Time-resolved spectra
