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 -27.024 sec. to 36.976 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.61558 ( -0.0803746 0.0799302 )
Norm@50keV : 7.62965E-03 ( -0.00036653 0.000365988 )
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#Fit statistic : Chi-Squared = 66.39 using 59 PHA bins.
# Reduced chi-squared = 1.165 for 57 degrees of freedom
# Null hypothesis probability = 1.847468e-01
Photon flux (15-150 keV) in 64 sec: 0.985270 ( -0.04905 0.04915 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.5588e-06 ( -2.30072e-07 2.30812e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -27.024 sec. to 36.976 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.811554 ( -0.35491 0.385493 )
Epeak [keV] : 75.6229 ( -10.2138 20.9745 )
Norm@50keV : 1.90201E-02 ( -0.00618305 0.0101375 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.95 using 59 PHA bins.
# Reduced chi-squared = 0.8919 for 56 degrees of freedom
# Null hypothesis probability = 7.021058e-01
Photon flux (15-150 keV) in 64 sec: 0.947571 ( -0.051525 0.051607 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.34931e-06 ( -2.48587e-07 2.48917e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -3.524 sec. to -2.524 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.76259 ( -0.388687 0.349476 )
Norm@50keV : 1.15633E-02 ( -0.00294315 0.00287506 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.55 using 59 PHA bins.
# Reduced chi-squared = 1.238 for 57 degrees of freedom
# Null hypothesis probability = 1.071270e-01
Photon flux (15-150 keV) in 1 sec: 1.57088 ( -0.36762 0.36846 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06655e-07 ( -2.72715e-08 2.77638e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.524 sec. to -2.524 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.488276 ( -1.81511 3.18421 )
Epeak [keV] : 58.1992 ( -13.1713 31.1282 )
Norm@50keV : 0.141246 ( -0.146024 3.79046 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.59 using 59 PHA bins.
# Reduced chi-squared = 1.171 for 56 degrees of freedom
# Null hypothesis probability = 1.784770e-01
Photon flux (15-150 keV) in 1 sec: 1.46020 ( -0.38638 0.38351 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.02459e-07 ( -2.61616e-08 2.76478e-08 ) ergs/cm2
Time-resolved spectra
