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 0.000 sec. to 9.498 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.66981 ( -0.298192 0.287146 )
Norm@50keV : 5.05147E-03 ( -0.000824046 0.000796622 )
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#Fit statistic : Chi-Squared = 62.44 using 59 PHA bins.
# Reduced chi-squared = 1.095 for 57 degrees of freedom
# Null hypothesis probability = 2.891309e-01
Photon flux (15-150 keV) in 9.498 sec: 0.663997 ( -0.098622 0.09878 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.45432e-07 ( -7.61981e-08 7.73152e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 9.498 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.01724 ( -0.00388965 0.0314367 )
Epeak [keV] : 7.18149 ( )
Norm@50keV : 3.20660E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.15 using 59 PHA bins.
# Reduced chi-squared = 1.092 for 56 degrees of freedom
# Null hypothesis probability = 2.964143e-01
Photon flux (15-150 keV) in 9.498 sec: 0.498189 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.93368e-07 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.900 sec. to 2.900 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.1272 ( -1.27631 1.11876 )
Norm@50keV : 5.22603E-03 ( -0.00521569 0.00238973 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.41 using 59 PHA bins.
# Reduced chi-squared = 0.9020 for 57 degrees of freedom
# Null hypothesis probability = 6.838042e-01
Photon flux (15-150 keV) in 1 sec: 0.604858 ( -0.604858 0.318195 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.43676e-08 ( -2.74721e-08 2.61406e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.900 sec. to 2.900 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.47819 ( 2.47974 2.39352 )
Epeak [keV] : 160.450 ( )
Norm@50keV : 1.41016E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.66 using 59 PHA bins.
# Reduced chi-squared = 0.9046 for 56 degrees of freedom
# Null hypothesis probability = 6.766248e-01
Photon flux (15-150 keV) in 1 sec: 0.612396 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.1425e-08 ( 0 0 ) ergs/cm2
Time-resolved spectra