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 -3.072 sec. to 271.324 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.98848 ( -0.295823 0.269798 )
Norm@50keV : 3.23031E-04 ( -6.18385e-05 5.92076e-05 )
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#Fit statistic : Chi-Squared = 61.69 using 59 PHA bins.
# Reduced chi-squared = 1.082 for 57 degrees of freedom
# Null hypothesis probability = 3.120807e-01
Photon flux (15-150 keV) in 274.4 sec: 4.82032E-02 ( -0.0065468 0.0065469 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.17078e-07 ( -1.42808e-07 1.47915e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.072 sec. to 271.324 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.07159 ( -1.01762 0.886159 )
Epeak [keV] : 39.8578 ( )
Norm@50keV : 2.90928E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.68 using 59 PHA bins.
# Reduced chi-squared = 1.101 for 56 degrees of freedom
# Null hypothesis probability = 2.802482e-01
Photon flux (15-150 keV) in 274.4 sec: 4.82410E-02 ( -0.0065027 0.0066292 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.22251e-07 ( -1.47561e-07 1.18196e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.556 sec. to 2.556 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.98421 ( -0.430172 0.381746 )
Norm@50keV : 3.47483E-03 ( -0.00102215 0.000984708 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.41 using 59 PHA bins.
# Reduced chi-squared = 0.9721 for 57 degrees of freedom
# Null hypothesis probability = 5.348704e-01
Photon flux (15-150 keV) in 1 sec: 0.517514 ( -0.109846 0.109887 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.20251e-08 ( -8.56877e-09 9.09555e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.556 sec. to 2.556 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.916133 ( -1.48454 4.95715 )
Epeak [keV] : 36.3733 ( -36.2801 -36.2801 )
Norm@50keV : 1.66339E-02 ( -0.017543 34.9379 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.77 using 59 PHA bins.
# Reduced chi-squared = 0.9780 for 56 degrees of freedom
# Null hypothesis probability = 5.216142e-01
Photon flux (15-150 keV) in 1 sec: 0.498909 ( -0.11773 0.117301 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.72615e-08 ( -9.20057e-09 1.18496e-08 ) ergs/cm2
Time-resolved spectra
