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 -0.264 sec. to 16.968 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.17664 ( -0.298174 0.31082 )
Norm@50keV : 6.93141E-03 ( -0.0011809 0.00117099 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 34.38 using 59 bins.
Reduced chi-squared = 0.603158
# Null hypothesis probability of 9.92e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 17.23 sec: 0.811035 ( -0.146431 0.14784 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21993e-06 ( -2.11827e-07 2.12473e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.264 sec. to 16.968 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.15555 ( -3.13715 2.14147 )
Epeak [keV] : 55.4589 ( )
Norm@50keV : 1.05589E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared 33.30 using 59 bins.
Reduced chi-squared = 0.594643
# Null hypothesis probability of 9.93e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 17.23 sec: 0.810418 ( -0.156731 0.148253 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21783e-06 ( -2.19793e-07 2.13621e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.924 sec. to 1.924 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.29563 ( -0.352483 0.355852 )
Norm@50keV : 2.25240E-02 ( -0.0049028 0.00489841 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 67.03 using 59 bins.
Reduced chi-squared = 1.17596
# Null hypothesis probability of 1.71e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.68525 ( -0.615 0.62367 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.22828e-07 ( -5.05261e-08 5.09068e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.924 sec. to 1.924 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.64305 ( -2.26041 4.82659 )
Epeak [keV] : 73.6551 ( -13.9022 47.5646 )
Norm@50keV : 0.367729 ( -0.371797 18.3521 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 61.30 using 59 bins.
Reduced chi-squared = 1.09464
# Null hypothesis probability of 2.92e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.27455 ( -0.66997 0.69601 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.00106e-07 ( -5.29595e-08 5.48587e-08 ) ergs/cm2
Time-resolved spectra
