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 -51.624 sec. to 268.212 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.55692 ( -0.0733503 0.0733574 )
Norm@50keV : 1.80277E-03 ( -7.3577e-05 7.3526e-05 )
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#Fit statistic : Chi-Squared = 60.83 using 59 PHA bins.
# Reduced chi-squared = 1.067 for 57 degrees of freedom
# Null hypothesis probability = 3.398372e-01
Photon flux (15-150 keV) in 319.8 sec: 0.228687 ( -0.009923 0.00995 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.42285e-06 ( -2.34747e-07 2.35614e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -51.624 sec. to 268.212 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.06608 ( -0.298623 0.321473 )
Epeak [keV] : 96.8085 ( -20.0782 68.6054 )
Norm@50keV : 3.14331E-03 ( -0.000882192 0.00134259 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.59 using 59 PHA bins.
# Reduced chi-squared = 0.9390 for 56 degrees of freedom
# Null hypothesis probability = 6.049091e-01
Photon flux (15-150 keV) in 319.8 sec: 0.221956 ( -0.010664 0.010686 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.2153e-06 ( -2.66971e-07 2.66568e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 182.188 sec. to 183.188 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.54686 ( -0.154795 0.153124 )
Norm@50keV : 1.61497E-02 ( -0.00150805 0.00150154 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.13 using 59 PHA bins.
# Reduced chi-squared = 0.7216 for 57 degrees of freedom
# Null hypothesis probability = 9.438451e-01
Photon flux (15-150 keV) in 1 sec: 2.04267 ( -0.19016 0.19053 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.52125e-07 ( -1.52229e-08 1.53654e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 182.188 sec. to 183.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.741883 ( -0.644939 0.764073 )
Epeak [keV] : 77.0857 ( -17.8404 103.084 )
Norm@50keV : 4.15211E-02 ( -0.0216683 0.0585652 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 36.43 using 59 PHA bins.
# Reduced chi-squared = 0.6505 for 56 degrees of freedom
# Null hypothesis probability = 9.802027e-01
Photon flux (15-150 keV) in 1 sec: 1.97268 ( -0.19861 0.19858 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.43509e-07 ( -1.68226e-08 1.69337e-08 ) ergs/cm2
Time-resolved spectra
