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 15.376 sec. to 184.332 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.54628 ( -0.224206 0.217475 )
Norm@50keV : 5.26418E-04 ( -7.20957e-05 7.11868e-05 )
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#Fit statistic : Chi-Squared = 53.94 using 59 PHA bins.
# Reduced chi-squared = 0.9463 for 57 degrees of freedom
# Null hypothesis probability = 5.905744e-01
Photon flux (15-150 keV) in 169 sec: 6.65718E-02 ( -0.0085272 0.0085329 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.38083e-07 ( -1.24463e-07 1.26716e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 15.376 sec. to 184.332 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.519519 ( -0.912842 1.1659 )
Epeak [keV] : 71.9912 ( -17.2513 144.861 )
Norm@50keV : 1.72869E-03 ( -0.00172829 0.00456877 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.17 using 59 PHA bins.
# Reduced chi-squared = 0.8958 for 56 degrees of freedom
# Null hypothesis probability = 6.943216e-01
Photon flux (15-150 keV) in 169 sec: 6.36661E-02 ( -0.0089779 0.0089356 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.8328e-07 ( -1.28271e-07 1.34032e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 23.532 sec. to 24.532 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.64619 ( -0.502543 0.464745 )
Norm@50keV : 3.06538E-03 ( -0.000980399 0.000943984 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.97 using 59 PHA bins.
# Reduced chi-squared = 0.9118 for 57 degrees of freedom
# Null hypothesis probability = 6.635907e-01
Photon flux (15-150 keV) in 1 sec: 0.399777 ( -0.109141 0.109142 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.85227e-08 ( -9.32099e-09 9.88957e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 23.532 sec. to 24.532 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.0283379 ( -2.21205 4.71846 )
Epeak [keV] : 49.4019 ( )
Norm@50keV : 2.67420E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.83 using 59 PHA bins.
# Reduced chi-squared = 0.9077 for 56 degrees of freedom
# Null hypothesis probability = 6.703997e-01
Photon flux (15-150 keV) in 1 sec: 0.374696 ( -0.11171 0.116163 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.32798e-08 ( -8.47065e-09 1.27067e-08 ) ergs/cm2
Time-resolved spectra
