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 -14.120 sec. to 13.352 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.87483 ( -0.093857 0.0922454 )
Norm@50keV : 3.21014E-03 ( -0.000191917 0.000190491 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 79.01 using 59 PHA bins.
# Reduced chi-squared = 1.386 for 57 degrees of freedom
# Null hypothesis probability = 2.844897e-02
Photon flux (15-150 keV) in 27.47 sec: 0.455873 ( -0.023669 0.023685 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.10791e-07 ( -4.81173e-08 4.85961e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -14.120 sec. to 13.352 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.385418 ( -0.541302 0.624621 )
Epeak [keV] : 44.7173 ( -3.81235 5.19255 )
Norm@50keV : 2.29283E-02 ( -0.0116758 0.0298197 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.00 using 59 PHA bins.
# Reduced chi-squared = 0.9107 for 56 degrees of freedom
# Null hypothesis probability = 6.641043e-01
Photon flux (15-150 keV) in 27.47 sec: 0.426138 ( -0.025418 0.025485 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.94942e-07 ( -5.40882e-08 5.74755e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -1.044 sec. to -0.044 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.66733 ( -0.257682 0.249685 )
Norm@50keV : 6.39529E-03 ( -0.00101239 0.000983376 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.51 using 59 PHA bins.
# Reduced chi-squared = 0.9563 for 57 degrees of freedom
# Null hypothesis probability = 5.691513e-01
Photon flux (15-150 keV) in 1 sec: 0.839935 ( -0.113452 0.113468 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.93882e-08 ( -9.86827e-09 1.0127e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.044 sec. to -0.044 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.67464 ( -0.251491 0.268549 )
Epeak [keV] : 9999.27 ( -9999.35 -9999.36 )
Norm@50keV : 6.36494E-03 ( -0.0010041 0.00760374 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.52 using 59 PHA bins.
# Reduced chi-squared = 0.9735 for 56 degrees of freedom
# Null hypothesis probability = 5.311196e-01
Photon flux (15-150 keV) in 1 sec: 0.843952 ( -0.139067 0.131006 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra