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 0.036 sec. to 1.900 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.57674 ( -0.321812 0.312837 )
Norm@50keV : 6.45978E-03 ( -0.00135537 0.00133015 )
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#Fit statistic : Chi-Squared = 56.43 using 59 PHA bins.
# Reduced chi-squared = 0.9899 for 57 degrees of freedom
# Null hypothesis probability = 4.965964e-01
Photon flux (15-150 keV) in 1.864 sec: 0.824271 ( -0.156526 0.156566 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.1295e-07 ( -2.51757e-08 2.60345e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.036 sec. to 1.900 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.165453 ( -1.49041 2.31753 )
Epeak [keV] : 54.0818 ( -14.8626 -54.014 )
Norm@50keV : 4.23430E-02 ( -0.0426594 0.961397 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.88 using 59 PHA bins.
# Reduced chi-squared = 0.9621 for 56 degrees of freedom
# Null hypothesis probability = 5.557057e-01
Photon flux (15-150 keV) in 1.864 sec: 0.784504 ( -0.160172 0.162057 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.57339e-08 ( -2.58567e-08 3.13105e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.128 sec. to 1.128 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.61048 ( -0.340707 0.327057 )
Norm@50keV : 8.49635E-03 ( -0.00193836 0.00189801 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.95 using 59 PHA bins.
# Reduced chi-squared = 0.8763 for 57 degrees of freedom
# Null hypothesis probability = 7.345108e-01
Photon flux (15-150 keV) in 1 sec: 1.09543 ( -0.222646 0.22266 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.93725e-08 ( -1.90027e-08 1.96742e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.128 sec. to 1.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.617681 ( -2.01637 3.13074 )
Epeak [keV] : 47.2318 ( -10.0144 61.9306 )
Norm@50keV : 0.173406 ( -0.186973 11.9823 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.20 using 59 PHA bins.
# Reduced chi-squared = 0.8250 for 56 degrees of freedom
# Null hypothesis probability = 8.218724e-01
Photon flux (15-150 keV) in 1 sec: 1.02583 ( -0.223951 0.22868 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.30188e-08 ( -1.65213e-08 2.28529e-08 ) ergs/cm2
Time-resolved spectra
