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 -98.760 sec. to 117.240 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.33102 ( -0.0428468 0.0429588 )
Norm@50keV : 4.01615E-03 ( -8.8938e-05 8.8881e-05 )
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#Fit statistic : Chi-Squared = 50.38 using 59 PHA bins.
# Reduced chi-squared = 0.8838 for 57 degrees of freedom
# Null hypothesis probability = 7.199914e-01
Photon flux (15-150 keV) in 216 sec: 0.481989 ( -0.011889 0.011943 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.51027e-06 ( -1.96007e-07 1.96433e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -98.760 sec. to 117.240 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.27485 ( -0.0588818 0.164032 )
Epeak [keV] : 691.353 ( -741.179 -998.027 )
Norm@50keV : 4.24954E-03 ( -0.000231249 0.000693485 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.51 using 59 PHA bins.
# Reduced chi-squared = 0.9020 for 56 degrees of freedom
# Null hypothesis probability = 6.818482e-01
Photon flux (15-150 keV) in 216 sec: 0.480996 ( -0.013916 0.013003 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.48856e-06 ( -2.11738e-07 2.0572e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 86.240 sec. to 87.240 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.885543 ( -0.050904 0.0512418 )
Norm@50keV : 6.58759E-02 ( -0.00196551 0.0019629 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.98 using 59 PHA bins.
# Reduced chi-squared = 1.175 for 57 degrees of freedom
# Null hypothesis probability = 1.718401e-01
Photon flux (15-150 keV) in 1 sec: 0.397252 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.43567e-07 ( -2.39026e-08 2.39359e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 86.240 sec. to 87.240 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.486808 ( -0.206963 0.217109 )
Epeak [keV] : 225.828 ( -58.4936 169.316 )
Norm@50keV : 9.78266E-02 ( -0.0177129 0.0226399 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.71 using 59 PHA bins.
# Reduced chi-squared = 0.9948 for 56 degrees of freedom
# Null hypothesis probability = 4.858729e-01
Photon flux (15-150 keV) in 1 sec: 7.45438 ( -0.2315 0.2316 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.32656e-07 ( -2.50036e-08 2.49441e-08 ) ergs/cm2
Time-resolved spectra
