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 35.444 sec. to 618.580 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.9094 ( -0.121234 0.118481 )
Norm@50keV : 7.27698E-04 ( -5.12663e-05 5.05068e-05 )
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#Fit statistic : Chi-Squared = 43.50 using 59 PHA bins.
# Reduced chi-squared = 0.7632 for 57 degrees of freedom
# Null hypothesis probability = 9.060429e-01
Photon flux (15-150 keV) in 583.1 sec: 0.104858 ( -0.0062114 0.006222 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.90214e-06 ( -2.67654e-07 2.71e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 35.444 sec. to 618.580 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.08636 ( -0.0587717 0.390663 )
Epeak [keV] : 37.8974 ( )
Norm@50keV : 5.88234E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.79 using 59 PHA bins.
# Reduced chi-squared = 0.7641 for 56 degrees of freedom
# Null hypothesis probability = 9.028596e-01
Photon flux (15-150 keV) in 583.1 sec: 0.101588 ( -0.0103022 0.007981 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.90564e-06 ( -4.04557e-07 1.83223e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 115.228 sec. to 116.228 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.49703 ( -0.346407 0.332414 )
Norm@50keV : 7.20667E-03 ( -0.00145783 0.00143573 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.88 using 59 PHA bins.
# Reduced chi-squared = 0.8400 for 57 degrees of freedom
# Null hypothesis probability = 7.998111e-01
Photon flux (15-150 keV) in 1 sec: 0.898980 ( -0.175722 0.17607 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.84085e-08 ( -1.50234e-08 1.52481e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 115.228 sec. to 116.228 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.02775 ( -1.37476 1.65476 )
Epeak [keV] : 109.903 ( -109.971 -109.971 )
Norm@50keV : 1.21687E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.49 using 59 PHA bins.
# Reduced chi-squared = 0.8481 for 56 degrees of freedom
# Null hypothesis probability = 7.836524e-01
Photon flux (15-150 keV) in 1 sec: 0.882790 ( -0.183256 0.18145 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.69854e-08 ( -1.54139e-08 1.6191e-08 ) ergs/cm2
Time-resolved spectra
