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 -0.288 sec. to 18.320 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.77793 ( -0.105205 0.103398 )
Norm@50keV : 8.34702E-03 ( -0.00054169 0.000538366 )
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#Fit statistic : Chi-Squared = 89.00 using 59 PHA bins.
# Reduced chi-squared = 1.561 for 57 degrees of freedom
# Null hypothesis probability = 4.277636e-03
Photon flux (15-150 keV) in 18.61 sec: 1.14056 ( -0.07093 0.07106 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.43158e-06 ( -9.49358e-08 9.54442e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.288 sec. to 18.320 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.805878 ( -0.463403 0.518114 )
Epeak [keV] : 58.6571 ( -7.48751 13.5702 )
Norm@50keV : 2.67747E-02 ( -0.0112303 0.0226151 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 74.69 using 59 PHA bins.
# Reduced chi-squared = 1.334 for 56 degrees of freedom
# Null hypothesis probability = 4.821568e-02
Photon flux (15-150 keV) in 18.61 sec: 1.09091 ( -0.0743 0.07444 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.33926e-06 ( -1.02445e-07 1.03835e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.284 sec. to 2.284 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.52869 ( -0.152688 0.151273 )
Norm@50keV : 2.80490E-02 ( -0.00262695 0.00261717 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.03 using 59 PHA bins.
# Reduced chi-squared = 1.106 for 57 degrees of freedom
# Null hypothesis probability = 2.715727e-01
Photon flux (15-150 keV) in 1 sec: 3.52943 ( -0.33309 0.33349 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.64923e-07 ( -2.66033e-08 2.6719e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.284 sec. to 2.284 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.21975 ( -0.389549 0.593564 )
Epeak [keV] : 130.310 ( -58.4087 -130.31 )
Norm@50keV : 4.00699E-02 ( -0.0133841 0.0375845 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.06 using 59 PHA bins.
# Reduced chi-squared = 1.108 for 56 degrees of freedom
# Null hypothesis probability = 2.690620e-01
Photon flux (15-150 keV) in 1 sec: 3.49790 ( -0.338 0.33802 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.6124e-07 ( -2.762e-08 2.75552e-08 ) ergs/cm2
Time-resolved spectra
