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 -0.144 sec. to 0.632 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.73703 ( -0.258844 0.273434 )
Norm@50keV : 1.35296E-02 ( -0.00201205 0.00197034 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.03 using 59 PHA bins.
# Reduced chi-squared = 0.8075 for 57 degrees of freedom
# Null hypothesis probability = 8.504854e-01
Photon flux (15-150 keV) in 0.776 sec: 1.55979 ( -0.22035 0.2215 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2607e-07 ( -1.88063e-08 1.89382e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.144 sec. to 0.632 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.589279 ( -0.38463 1.23499 )
Epeak [keV] : 611.578 ( -611.507 -611.507 )
Norm@50keV : 1.54616E-02 ( -0.00340321 0.0276541 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.97 using 59 PHA bins.
# Reduced chi-squared = 0.8208 for 56 degrees of freedom
# Null hypothesis probability = 8.282993e-01
Photon flux (15-150 keV) in 0.776 sec: 1.54914 ( -0.23271 0.2283 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25514e-07 ( -1.94688e-08 1.90937e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.256 sec. to 0.744 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.677033 ( -0.285083 0.304706 )
Norm@50keV : 1.02104E-02 ( -0.00174781 0.0016969 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.05 using 59 PHA bins.
# Reduced chi-squared = 0.9308 for 57 degrees of freedom
# Null hypothesis probability = 6.238642e-01
Photon flux (15-150 keV) in 1 sec: 1.18248 ( -0.186615 0.1878 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25951e-07 ( -2.02887e-08 2.03947e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.256 sec. to 0.744 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.157066 ( -0.646902 1.89522 )
Epeak [keV] : 237.764 ( -237.657 -237.657 )
Norm@50keV : 1.58420E-02 ( -0.0070746 0.0493481 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.60 using 59 PHA bins.
# Reduced chi-squared = 0.9394 for 56 degrees of freedom
# Null hypothesis probability = 6.041797e-01
Photon flux (15-150 keV) in 1 sec: 1.15294 ( -0.204763 0.20083 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2448e-07 ( -2.12276e-08 2.09118e-08 ) ergs/cm2
Time-resolved spectra
