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 -24.112 sec. to 20.332 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.7362 ( -0.0842692 0.0833918 )
Norm@50keV : 5.14748E-03 ( -0.000250348 0.000249051 )
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#Fit statistic : Chi-Squared = 73.00 using 59 PHA bins.
# Reduced chi-squared = 1.281 for 57 degrees of freedom
# Null hypothesis probability = 7.509017e-02
Photon flux (15-150 keV) in 44.44 sec: 0.692551 ( -0.032416 0.032467 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.11288e-06 ( -1.06724e-07 1.07332e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -24.112 sec. to 20.332 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.25574 ( -0.351691 0.385008 )
Epeak [keV] : 72.8390 ( -14.4244 67.5812 )
Norm@50keV : 9.20353E-03 ( -0.00312842 0.00536033 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.42 using 59 PHA bins.
# Reduced chi-squared = 1.204 for 56 degrees of freedom
# Null hypothesis probability = 1.411597e-01
Photon flux (15-150 keV) in 44.44 sec: 0.673927 ( -0.035061 0.035041 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.0189e-06 ( -1.26012e-07 1.26434e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.096 sec. to 0.904 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.13067 ( -0.133737 0.135538 )
Norm@50keV : 2.62627E-02 ( -0.00199174 0.00199132 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.12 using 59 PHA bins.
# Reduced chi-squared = 1.107 for 57 degrees of freedom
# Null hypothesis probability = 2.689130e-01
Photon flux (15-150 keV) in 1 sec: 3.05599 ( -0.23755 0.23793 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.71982e-07 ( -2.30332e-08 2.31933e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.096 sec. to 0.904 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.07996 ( -0.173557 0.528056 )
Epeak [keV] : 979.872 ( -990.098 -990.098 )
Norm@50keV : 2.77736E-02 ( -0.00319263 0.0210254 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.13 using 59 PHA bins.
# Reduced chi-squared = 1.127 for 56 degrees of freedom
# Null hypothesis probability = 2.391120e-01
Photon flux (15-150 keV) in 1 sec: 3.05396 ( -0.25055 0.24392 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.71063e-07 ( -2.45102e-08 2.39424e-08 ) ergs/cm2
Time-resolved spectra
