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 -31.192 sec. to 32.808 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.8312 ( -0.116178 0.1139 )
Norm@50keV : 1.01317E-02 ( -0.000667229 0.000661633 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.81 using 59 PHA bins.
# Reduced chi-squared = 1.049 for 57 degrees of freedom
# Null hypothesis probability = 3.740528e-01
Photon flux (15-150 keV) in 64 sec: 1.41346 ( -0.09148 0.09185 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.96513e-06 ( -3.95456e-07 3.97399e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -31.192 sec. to 32.808 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.06502 ( -0.756857 0.262776 )
Epeak [keV] : 28.8788 ( -9999.35 -9999.36 )
Norm@50keV : 7.64157E-03 ( -0.00104519 0.00110783 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.59 using 59 PHA bins.
# Reduced chi-squared = 1.064 for 56 degrees of freedom
# Null hypothesis probability = 3.464089e-01
Photon flux (15-150 keV) in 64 sec: 1.41971 ( -0.09779 0.08544 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.99694e-06 ( -5.72313e-07 3.57539e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 8.308 sec. to 9.308 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.82425 ( -0.964868 0.611469 )
Norm@50keV : 6.41579E-03 ( -0.00392741 0.00373941 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.10 using 59 PHA bins.
# Reduced chi-squared = 0.8438 for 57 degrees of freedom
# Null hypothesis probability = 7.933796e-01
Photon flux (15-150 keV) in 1 sec: 1.55773 ( -0.62156 0.6225 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.15385e-08 ( -3.06689e-08 3.12939e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.308 sec. to 9.308 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.842877 ( -1.16983 4.4748 )
Epeak [keV] : 26.6121 ( )
Norm@50keV : 8.42710E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.69 using 59 PHA bins.
# Reduced chi-squared = 0.8337 for 56 degrees of freedom
# Null hypothesis probability = 8.079234e-01
Photon flux (15-150 keV) in 1 sec: 1.56274 ( -0.634076 0.62848 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.57234e-08 ( 0 0 ) ergs/cm2
Time-resolved spectra
