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 -0.252 sec. to 20.508 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.52162 ( -0.457954 0.434804 )
Norm@50keV : 9.62577E-04 ( -0.000248419 0.000238747 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.09 using 59 PHA bins.
# Reduced chi-squared = 0.9314 for 57 degrees of freedom
# Null hypothesis probability = 6.225723e-01
Photon flux (15-150 keV) in 20.76 sec: 0.120883 ( -0.0284276 0.028472 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.88942e-07 ( -5.24244e-08 5.39415e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.252 sec. to 20.508 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.5056 ( )
Epeak [keV] : 9974.72 ( )
Norm@50keV : 9.79766E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.10 using 59 PHA bins.
# Reduced chi-squared = 0.9482 for 56 degrees of freedom
# Null hypothesis probability = 5.853748e-01
Photon flux (15-150 keV) in 20.76 sec: 0.121363 ( -0.0439322 0.028776 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.89752e-07 ( -5.60505e-08 3.83697e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 19.312 sec. to 20.312 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.20217 ( -0.388453 0.399472 )
Norm@50keV : 5.67929E-03 ( -0.00116424 0.0011638 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.68 using 59 PHA bins.
# Reduced chi-squared = 0.6259 for 57 degrees of freedom
# Null hypothesis probability = 9.879541e-01
Photon flux (15-150 keV) in 1 sec: 0.666839 ( -0.139498 0.140121 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.75904e-08 ( -1.34425e-08 1.36539e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 19.312 sec. to 20.312 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.52951 ( -1.47655 2.18967 )
Epeak [keV] : 169.086 ( )
Norm@50keV : 1.06151E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 35.17 using 59 PHA bins.
# Reduced chi-squared = 0.6281 for 56 degrees of freedom
# Null hypothesis probability = 9.867525e-01
Photon flux (15-150 keV) in 1 sec: 0.666724 ( -0.139752 0.140013 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.79215e-08 ( -1.68368e-08 7.63262e-09 ) ergs/cm2
Time-resolved spectra
