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 -10.008 sec. to 25.588 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.00611 ( -0.0641999 0.0635331 )
Norm@50keV : 1.48188E-02 ( -0.000522661 0.000520661 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.02 using 59 PHA bins.
# Reduced chi-squared = 0.8073 for 57 degrees of freedom
# Null hypothesis probability = 8.507754e-01
Photon flux (15-150 keV) in 35.6 sec: 2.22925 ( -0.08226 0.08264 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.86745e-06 ( -1.65799e-07 1.66054e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -10.008 sec. to 25.588 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.65656 ( -0.259158 0.276332 )
Epeak [keV] : 47.8950 ( -14.0589 13.1166 )
Norm@50keV : 2.22799E-02 ( -0.00568209 0.00830965 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.62 using 59 PHA bins.
# Reduced chi-squared = 0.7253 for 56 degrees of freedom
# Null hypothesis probability = 9.392158e-01
Photon flux (15-150 keV) in 35.6 sec: 2.17119 ( -0.09169 0.09215 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.73306e-06 ( -1.93117e-07 1.92441e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -3.692 sec. to -2.692 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.73628 ( -0.158793 0.153798 )
Norm@50keV : 3.03140E-02 ( -0.00318023 0.00315425 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.99 using 59 PHA bins.
# Reduced chi-squared = 1.053 for 57 degrees of freedom
# Null hypothesis probability = 3.677137e-01
Photon flux (15-150 keV) in 1 sec: 4.07858 ( -0.40854 0.40913 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.79995e-07 ( -3.01791e-08 3.03823e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.692 sec. to -2.692 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.0507957 ( -0.834946 1.03314 )
Epeak [keV] : 55.8559 ( -7.26215 12.1504 )
Norm@50keV : 0.226653 ( -0.14147 0.543149 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.99 using 59 PHA bins.
# Reduced chi-squared = 0.8213 for 56 degrees of freedom
# Null hypothesis probability = 8.275885e-01
Photon flux (15-150 keV) in 1 sec: 3.56341 ( -0.60159 0.48567 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.59406e-07 ( -3.12247e-08 3.19608e-08 ) ergs/cm2
Time-resolved spectra
