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 0.008 sec. to 0.056 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.40896 ( -0.237794 0.233253 )
Norm@50keV : 4.81823E-02 ( -0.00788995 0.00787016 )
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#Fit statistic : Chi-Squared = 44.74 using 59 PHA bins.
# Reduced chi-squared = 0.7850 for 57 degrees of freedom
# Null hypothesis probability = 8.807372e-01
Photon flux (15-150 keV) in 0.048 sec: 5.87988 ( -0.96951 0.97055 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.23096e-08 ( -3.91622e-09 3.93086e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.008 sec. to 0.056 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.151045 ( -1.00202 1.27295 )
Epeak [keV] : 79.7569 ( -19.3128 93.9538 )
Norm@50keV : 0.195515 ( -0.195515 0.561146 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 39.99 using 59 PHA bins.
# Reduced chi-squared = 0.7141 for 56 degrees of freedom
# Null hypothesis probability = 9.476776e-01
Photon flux (15-150 keV) in 0.048 sec: 5.83860 ( -0.97639 0.97634 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.21387e-08 ( -4.04688e-09 4.04204e-09 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.466 sec. to 0.534 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.01852 ( -0.738818 0.838218 )
Norm@50keV : 2.56406E-03 ( -0.00112072 0.00109195 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.44 using 59 PHA bins.
# Reduced chi-squared = 0.9903 for 57 degrees of freedom
# Null hypothesis probability = 4.958786e-01
Photon flux (15-150 keV) in 1 sec: 0.295508 ( -0.128141 0.129919 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.75499e-08 ( -1.23097e-08 1.2619e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.466 sec. to 0.534 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.332599 ( 0.332635 5.08098 )
Epeak [keV] : 137.778 ( -137.781 -137.781 )
Norm@50keV : 5.21760E-03 ( -0.00521745 1.53631 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.27 using 59 PHA bins.
# Reduced chi-squared = 1.005 for 56 degrees of freedom
# Null hypothesis probability = 4.649157e-01
Photon flux (15-150 keV) in 1 sec: 0.287492 ( -0.130847 0.133628 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.65938e-08 ( -1.34791e-08 1.382e-08 ) ergs/cm2
Time-resolved spectra
