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 -1.224 sec. to 4.520 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.10552 ( -0.403144 0.35626 )
Norm@50keV : 1.36950E-03 ( -0.000399684 0.000393865 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.31 using 59 PHA bins.
# Reduced chi-squared = 1.093 for 57 degrees of freedom
# Null hypothesis probability = 2.929173e-01
Photon flux (15-150 keV) in 5.744 sec: 0.216062 ( -0.044058 0.044115 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.31349e-08 ( -1.87167e-08 1.99704e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.224 sec. to 4.520 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.47728 ( -2.28629 7.34479 )
Epeak [keV] : 31.2362 ( -7.40002 12.6119 )
Norm@50keV : 0.337298 ( -0.317405 8471.08 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.11 using 59 PHA bins.
# Reduced chi-squared = 1.038 for 56 degrees of freedom
# Null hypothesis probability = 3.973423e-01
Photon flux (15-150 keV) in 5.744 sec: 0.202887 ( -0.043358 0.0443 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.53075e-08 ( -1.46235e-08 2.22483e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.716 sec. to 1.716 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.68405 ( -0.577555 0.540071 )
Norm@50keV : 2.34740E-03 ( -0.000920863 0.000901579 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.05 using 59 PHA bins.
# Reduced chi-squared = 0.9307 for 57 degrees of freedom
# Null hypothesis probability = 6.240239e-01
Photon flux (15-150 keV) in 1 sec: 0.310040 ( -0.107982 0.108026 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.17826e-08 ( -8.58728e-09 9.1531e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.716 sec. to 1.716 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 6.81498 ( -7.71027 -6.83307 )
Epeak [keV] : 33.4660 ( -5.42546 27.1885 )
Norm@50keV : 937.875 ( -1007.16 174704 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.69 using 59 PHA bins.
# Reduced chi-squared = 0.8695 for 56 degrees of freedom
# Null hypothesis probability = 7.450862e-01
Photon flux (15-150 keV) in 1 sec: 0.273793 ( -0.093675 0.102715 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.34524e-08 ( -4.7632e-09 9.25461e-09 ) ergs/cm2
Time-resolved spectra
