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 -63.412 sec. to 65.792 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.57103 ( -0.0540108 0.0538573 )
Norm@50keV : 7.15327E-03 ( -0.000201658 0.000201523 )
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#Fit statistic : Chi-Squared = 52.99 using 59 PHA bins.
# Reduced chi-squared = 0.9297 for 57 degrees of freedom
# Null hypothesis probability = 6.261940e-01
Photon flux (15-150 keV) in 129.2 sec: 0.911200 ( -0.027524 0.027599 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.67646e-06 ( -2.61108e-07 2.61785e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -63.412 sec. to 65.792 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.32242 ( -0.211058 0.222112 )
Epeak [keV] : 142.578 ( -43.7112 413.978 )
Norm@50keV : 9.39952E-03 ( -0.00189864 0.00252775 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.92 using 59 PHA bins.
# Reduced chi-squared = 0.8735 for 56 degrees of freedom
# Null hypothesis probability = 7.376292e-01
Photon flux (15-150 keV) in 129.2 sec: 0.894393 ( -0.030699 0.03079 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.50007e-06 ( -3.01792e-07 3.00334e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.092 sec. to 3.092 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.18837 ( -0.0784471 0.0786508 )
Norm@50keV : 4.98614E-02 ( -0.00229695 0.00229695 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.01 using 59 PHA bins.
# Reduced chi-squared = 0.8773 for 57 degrees of freedom
# Null hypothesis probability = 7.326547e-01
Photon flux (15-150 keV) in 1 sec: 5.84334 ( -0.27645 0.27668 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.07598e-07 ( -2.59165e-08 2.60071e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.092 sec. to 3.092 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.562212 ( -0.334206 0.362369 )
Epeak [keV] : 126.951 ( -27.5593 79.1503 )
Norm@50keV : 9.71171E-02 ( -0.0284202 0.0439106 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 39.10 using 59 PHA bins.
# Reduced chi-squared = 0.6982 for 56 degrees of freedom
# Null hypothesis probability = 9.580796e-01
Photon flux (15-150 keV) in 1 sec: 5.69569 ( -0.28731 0.28717 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.14594e-07 ( -1.68478e-08 2.82658e-08 ) ergs/cm2
Time-resolved spectra
