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 -43.752 sec. to 164.872 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.07327 ( -0.177887 0.169607 )
Norm@50keV : 1.32160E-03 ( -0.000148839 0.000145772 )
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#Fit statistic : Chi-Squared = 63.95 using 59 PHA bins.
# Reduced chi-squared = 1.122 for 57 degrees of freedom
# Null hypothesis probability = 2.456834e-01
Photon flux (15-150 keV) in 208.6 sec: 0.205237 ( -0.018011 0.018029 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.55566e-06 ( -2.59914e-07 2.64826e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -43.752 sec. to 164.872 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.60784 ( -0.527694 0.871345 )
Epeak [keV] : 35.1526 ( -27.4348 -35.1532 )
Norm@50keV : 2.44334E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.76 using 59 PHA bins.
# Reduced chi-squared = 1.121 for 56 degrees of freedom
# Null hypothesis probability = 2.492082e-01
Photon flux (15-150 keV) in 208.6 sec: 0.200617 ( -0.019433 0.019363 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.43054e-06 ( -3.13382e-07 3.24853e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -15.364 sec. to -14.364 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.53855 ( -0.773291 0.688758 )
Norm@50keV : 4.75629E-03 ( -0.00189251 0.00181738 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.82 using 59 PHA bins.
# Reduced chi-squared = 0.8917 for 57 degrees of freedom
# Null hypothesis probability = 7.045838e-01
Photon flux (15-150 keV) in 1 sec: 0.600159 ( -0.231855 0.234252 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.4857e-08 ( -1.84627e-08 1.89223e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.364 sec. to -14.364 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.627461 ( -2.088 0.626314 )
Epeak [keV] : 88.1587 ( -88.1378 -88.1378 )
Norm@50keV : 1.17836E-02 ( -0.0120632 197.942 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.58 using 59 PHA bins.
# Reduced chi-squared = 0.9033 for 56 degrees of freedom
# Null hypothesis probability = 6.792832e-01
Photon flux (15-150 keV) in 1 sec: 0.564390 ( -0.335026 0.257704 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.90008e-08 ( -2.87638e-08 2.28482e-08 ) ergs/cm2
Time-resolved spectra
