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 -11.488 sec. to 69.244 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.27732 ( -0.126004 0.126987 )
Norm@50keV : 4.05925E-03 ( -0.000292525 0.000292455 )
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#Fit statistic : Chi-Squared = 58.36 using 59 PHA bins.
# Reduced chi-squared = 1.024 for 57 degrees of freedom
# Null hypothesis probability = 4.252667e-01
Photon flux (15-150 keV) in 80.73 sec: 0.482319 ( -0.036692 0.036803 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.25698e-06 ( -2.51907e-07 2.53085e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.488 sec. to 69.244 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.844447 ( -0.475937 0.556998 )
Epeak [keV] : 149.464 ( -54.7413 -149.464 )
Norm@50keV : 6.39394E-03 ( -0.00243873 0.0048207 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.12 using 59 PHA bins.
# Reduced chi-squared = 1.002 for 56 degrees of freedom
# Null hypothesis probability = 4.705032e-01
Photon flux (15-150 keV) in 80.73 sec: 0.472021 ( -0.038527 0.038583 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.1879e-06 ( -2.68019e-07 2.66838e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 59.596 sec. to 60.596 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.700165 ( -0.12927 0.134205 )
Norm@50keV : 2.36289E-02 ( -0.00189881 0.00187873 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 72.47 using 59 PHA bins.
# Reduced chi-squared = 1.271 for 57 degrees of freedom
# Null hypothesis probability = 8.126769e-02
Photon flux (15-150 keV) in 1 sec: 2.73122 ( -0.20844 0.20885 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.8843e-07 ( -2.25657e-08 2.26557e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 59.596 sec. to 60.596 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.135258 ( -0.525537 0.608663 )
Epeak [keV] : 201.335 ( -73.5645 5096.51 )
Norm@50keV : 4.06865E-02 ( -0.0157158 0.0302213 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.10 using 59 PHA bins.
# Reduced chi-squared = 1.234 for 56 degrees of freedom
# Null hypothesis probability = 1.122168e-01
Photon flux (15-150 keV) in 1 sec: 2.68389 ( -0.21294 0.21329 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.828e-07 ( -2.40145e-08 2.3735e-08 ) ergs/cm2
Time-resolved spectra
