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 -44.116 sec. to 134.052 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.24049 ( -0.198631 0.186806 )
Norm@50keV : 6.78370E-04 ( -9.42176e-05 9.32692e-05 )
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#Fit statistic : Chi-Squared = 58.28 using 59 PHA bins.
# Reduced chi-squared = 1.022 for 57 degrees of freedom
# Null hypothesis probability = 4.279677e-01
Photon flux (15-150 keV) in 178.2 sec: 0.114764 ( -0.010173 0.010173 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.14371e-06 ( -1.30695e-07 1.3569e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -44.116 sec. to 134.052 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.22401 ( -0.467269 0.172404 )
Epeak [keV] : 9999.36 ( )
Norm@50keV : 6.88675E-04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.31 using 59 PHA bins.
# Reduced chi-squared = 1.041 for 56 degrees of freedom
# Null hypothesis probability = 3.904601e-01
Photon flux (15-150 keV) in 178.2 sec: 0.110516 ( -0.0106661 0.01082 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.02037e-06 ( -1.4404e-07 1.70948e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.340 sec. to 0.660 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.28417 ( -0.140579 0.139866 )
Norm@50keV : 1.80901E-02 ( -0.00140991 0.00140607 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.38 using 59 PHA bins.
# Reduced chi-squared = 1.358 for 57 degrees of freedom
# Null hypothesis probability = 3.752043e-02
Photon flux (15-150 keV) in 1 sec: 2.15205 ( -0.16624 0.16637 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.79486e-07 ( -1.62071e-08 1.6394e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.340 sec. to 0.660 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.11426 ( -0.292874 0.548147 )
Epeak [keV] : 273.377 ( -273.358 -273.358 )
Norm@50keV : 2.18717E-02 ( -0.00502682 0.0176836 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.04 using 59 PHA bins.
# Reduced chi-squared = 1.376 for 56 degrees of freedom
# Null hypothesis probability = 3.258107e-02
Photon flux (15-150 keV) in 1 sec: 2.13387 ( -0.17456 0.17405 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.77129e-07 ( -1.77761e-08 1.76132e-08 ) ergs/cm2
Time-resolved spectra
