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 -17.320 sec. to 3.168 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.58317 ( -0.134791 0.132983 )
Norm@50keV : 2.45857E-03 ( -0.000200524 0.000198706 )
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#Fit statistic : Chi-Squared = 67.38 using 59 PHA bins.
# Reduced chi-squared = 1.182 for 57 degrees of freedom
# Null hypothesis probability = 1.634283e-01
Photon flux (15-150 keV) in 20.49 sec: 0.314323 ( -0.023752 0.023761 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.72184e-07 ( -4.17742e-08 4.23239e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -17.320 sec. to 3.168 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.15401 ( -0.486662 0.621238 )
Epeak [keV] : 89.8226 ( -30.0036 -89.8753 )
Norm@50keV : 4.21130E-03 ( -0.00186326 0.00485856 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.61 using 59 PHA bins.
# Reduced chi-squared = 1.172 for 56 degrees of freedom
# Null hypothesis probability = 1.780315e-01
Photon flux (15-150 keV) in 20.49 sec: 0.308445 ( -0.024991 0.024878 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.50622e-07 ( -4.95506e-08 5.01405e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.216 sec. to 1.216 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.35407 ( -0.132486 0.131941 )
Norm@50keV : 1.19472E-02 ( -0.00101446 0.00101174 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.33 using 59 PHA bins.
# Reduced chi-squared = 1.234 for 57 degrees of freedom
# Null hypothesis probability = 1.104991e-01
Photon flux (15-150 keV) in 1 sec: 1.44053 ( -0.1205 0.12054 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.16592e-07 ( -1.1027e-08 1.11342e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.216 sec. to 1.216 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.109373 ( -0.654802 0.775889 )
Epeak [keV] : 73.7072 ( -12.5507 30.1559 )
Norm@50keV : 5.29134E-02 ( -0.0283114 0.0781048 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.43 using 59 PHA bins.
# Reduced chi-squared = 1.043 for 56 degrees of freedom
# Null hypothesis probability = 3.860819e-01
Photon flux (15-150 keV) in 1 sec: 1.38985 ( -0.12413 0.12379 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06429e-07 ( -1.19946e-08 1.2279e-08 ) ergs/cm2
Time-resolved spectra
