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 0.624 sec. to 20.320 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.21832 ( -0.258055 0.267894 )
Norm@50keV : 8.57885E-03 ( -0.00124844 0.00123997 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.44 using 59 PHA bins.
# Reduced chi-squared = 0.9551 for 57 degrees of freedom
# Null hypothesis probability = 5.717613e-01
Photon flux (15-150 keV) in 19.7 sec: 1.00966 ( -0.157965 0.15995 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.70607e-06 ( -2.51593e-07 2.52489e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.624 sec. to 20.320 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.10304 ( -2.11042 1.02244 )
Epeak [keV] : 442.955 ( -347.747 -347.747 )
Norm@50keV : 9.64443E-03 ( -0.00194643 0.0182358 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.41 using 59 PHA bins.
# Reduced chi-squared = 0.9716 for 56 degrees of freedom
# Null hypothesis probability = 5.352495e-01
Photon flux (15-150 keV) in 19.7 sec: 1.00408 ( -0.166227 0.15632 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.65324e-07 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 6.884 sec. to 7.884 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.51943 ( -0.890348 0.630066 )
Norm@50keV : 7.60223E-03 ( -0.00760226 0.00364237 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 76.62 using 59 PHA bins.
# Reduced chi-squared = 1.344 for 57 degrees of freedom
# Null hypothesis probability = 4.257701e-02
Photon flux (15-150 keV) in 1 sec: 1.51160 ( -0.652171 0.6558 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.64434e-08 ( -3.22406e-08 3.22717e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 6.884 sec. to 7.884 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.75362 ( )
Epeak [keV] : 15.7768 ( )
Norm@50keV : 1.96470E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 76.43 using 59 PHA bins.
# Reduced chi-squared = 1.365 for 56 degrees of freedom
# Null hypothesis probability = 3.617196e-02
Photon flux (15-150 keV) in 1 sec: 1.49857 ( -0.653935 0.65078 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.74694e-08 ( -3.2568e-08 3.26465e-08 ) ergs/cm2
Time-resolved spectra
