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 -1.920 sec. to 50.232 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.95752 ( -0.112743 0.110399 )
Norm@50keV : 4.77320E-03 ( -0.000328154 0.000324601 )
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#Fit statistic : Chi-Squared = 58.13 using 59 PHA bins.
# Reduced chi-squared = 1.020 for 57 degrees of freedom
# Null hypothesis probability = 4.334711e-01
Photon flux (15-150 keV) in 52.15 sec: 0.702402 ( -0.041424 0.04148 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.29168e-06 ( -1.51233e-07 1.52957e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.920 sec. to 50.232 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29008 ( -0.517742 0.610357 )
Epeak [keV] : 44.5909 ( -8.84666 17.6956 )
Norm@50keV : 1.14390E-02 ( -0.00556304 0.0140927 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.13 using 59 PHA bins.
# Reduced chi-squared = 0.9487 for 56 degrees of freedom
# Null hypothesis probability = 5.842377e-01
Photon flux (15-150 keV) in 52.15 sec: 0.677605 ( -0.045614 0.045461 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.11999e-06 ( -1.92137e-07 1.9812e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.120 sec. to 0.880 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31418 ( -0.257491 0.257131 )
Norm@50keV : 1.66639E-02 ( -0.00244744 0.00243949 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.40 using 59 PHA bins.
# Reduced chi-squared = 0.8843 for 57 degrees of freedom
# Null hypothesis probability = 7.191400e-01
Photon flux (15-150 keV) in 1 sec: 1.99335 ( -0.29428 0.29488 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.64127e-07 ( -2.71051e-08 2.74485e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.120 sec. to 0.880 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.15051 ( -1.31744 1.18721 )
Epeak [keV] : 270.764 ( -270.778 -270.778 )
Norm@50keV : 2.00571E-02 ( -0.00572954 0.0533114 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.33 using 59 PHA bins.
# Reduced chi-squared = 0.8987 for 56 degrees of freedom
# Null hypothesis probability = 6.885154e-01
Photon flux (15-150 keV) in 1 sec: 1.98024 ( -0.30616 0.30353 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62301e-07 ( -2.97479e-08 2.88119e-08 ) ergs/cm2
Time-resolved spectra
