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 -6.000 sec. to 182.040 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.35449 ( -0.072692 0.0729432 )
Norm@50keV : 2.85939E-03 ( -0.000115399 0.000115391 )
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#Fit statistic : Chi-Squared = 57.56 using 59 PHA bins.
# Reduced chi-squared = 1.010 for 57 degrees of freedom
# Null hypothesis probability = 4.542259e-01
Photon flux (15-150 keV) in 188 sec: 0.344798 ( -0.014661 0.014689 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.24563e-06 ( -2.30552e-07 2.31306e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.000 sec. to 182.040 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.957906 ( -0.2884 0.309207 )
Epeak [keV] : 139.844 ( -39.1668 207.937 )
Norm@50keV : 4.41148E-03 ( -0.00116567 0.00171362 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.91 using 59 PHA bins.
# Reduced chi-squared = 0.9269 for 56 degrees of freedom
# Null hypothesis probability = 6.304206e-01
Photon flux (15-150 keV) in 188 sec: 0.337159 ( -0.015625 0.015636 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.0988e-06 ( -2.55766e-07 2.54943e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 109.948 sec. to 110.948 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.17113 ( -0.131866 0.132572 )
Norm@50keV : 2.66357E-02 ( -0.00207207 0.00207127 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.36 using 59 PHA bins.
# Reduced chi-squared = 0.9537 for 57 degrees of freedom
# Null hypothesis probability = 5.746667e-01
Photon flux (15-150 keV) in 1 sec: 3.11439 ( -0.24521 0.24534 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.72515e-07 ( -2.40187e-08 2.41935e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 109.948 sec. to 110.948 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.860491 ( -0.374452 0.561646 )
Epeak [keV] : 195.401 ( -195.403 -195.403 )
Norm@50keV : 3.76609E-02 ( -0.0125082 0.0313741 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.27 using 59 PHA bins.
# Reduced chi-squared = 0.9513 for 56 degrees of freedom
# Null hypothesis probability = 5.787432e-01
Photon flux (15-150 keV) in 1 sec: 3.08280 ( -0.25105 0.25073 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.67424e-07 ( -2.59335e-08 2.56856e-08 ) ergs/cm2
Time-resolved spectra
