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 -6.188 sec. to 140.344 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.43236 ( -0.0437445 0.0437598 )
Norm@50keV : 1.99948E-02 ( -0.000473491 0.000473325 )
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#Fit statistic : Chi-Squared = 47.48 using 59 PHA bins.
# Reduced chi-squared = 0.8330 for 57 degrees of freedom
# Null hypothesis probability = 8.114154e-01
Photon flux (15-150 keV) in 146.5 sec: 2.45354 ( -0.06566 0.06586 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.81273e-05 ( -6.84518e-07 6.85012e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.188 sec. to 140.344 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.26851 ( -0.0819677 0.178912 )
Epeak [keV] : 260.481 ( -105.284 -260.486 )
Norm@50keV : 2.35610E-02 ( -0.00315347 0.00449237 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.86 using 59 PHA bins.
# Reduced chi-squared = 0.8011 for 56 degrees of freedom
# Null hypothesis probability = 8.570990e-01
Photon flux (15-150 keV) in 146.5 sec: 2.42418 ( -0.0718 0.07206 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.79137e-05 ( -7.23143e-07 7.21359e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 13.740 sec. to 14.740 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.20922 ( -0.0767445 0.0766503 )
Norm@50keV : 0.421255 ( -0.0199733 0.0199733 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.33 using 59 PHA bins.
# Reduced chi-squared = 1.041 for 57 degrees of freedom
# Null hypothesis probability = 3.907679e-01
Photon flux (15-150 keV) in 1 sec: 49.5120 ( -2.4146 2.4165 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.26324e-06 ( -2.20647e-07 2.21115e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 13.740 sec. to 14.740 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.540157 ( -0.32962 0.354567 )
Epeak [keV] : 124.207 ( -24.7781 63.9589 )
Norm@50keV : 0.850392 ( -0.243235 0.368535 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.52 using 59 PHA bins.
# Reduced chi-squared = 0.8307 for 56 degrees of freedom
# Null hypothesis probability = 8.127402e-01
Photon flux (15-150 keV) in 1 sec: 48.6082 ( -2.4502 2.4537 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.19257e-06 ( -2.29698e-07 2.29036e-07 ) ergs/cm2
Time-resolved spectra
