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 -0.756 sec. to 96.516 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.70432 ( -0.0559771 0.0557253 )
Norm@50keV : 5.27383E-03 ( -0.000158241 0.000157985 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 60.86 using 59 bins.
Reduced chi-squared = 1.06772
# Null hypothesis probability of 3.39e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 97.27 sec: 0.701514 ( -0.022049 0.022113 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.74875e-06 ( -1.48527e-07 1.48913e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.756 sec. to 96.516 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.04726 ( -0.250003 0.26558 )
Epeak [keV] : 71.9689 ( -8.18034 15.1298 )
Norm@50keV : 1.11601E-02 ( -0.00271523 0.00387413 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 38.83 using 59 bins.
Reduced chi-squared = 0.693393
# Null hypothesis probability of 9.61e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 97.27 sec: 0.668007 ( -0.024887 0.025024 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.4732e-06 ( -1.78147e-07 1.78573e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 15.948 sec. to 16.948 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.31109 ( -0.137085 0.137154 )
Norm@50keV : 1.99583E-02 ( -0.00168528 0.00168304 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 81.86 using 59 bins.
Reduced chi-squared = 1.43614
# Null hypothesis probability of 1.71e-02 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.38604 ( -0.20221 0.20238 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.96716e-07 ( -1.84986e-08 1.86762e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 15.948 sec. to 16.948 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.375647 ( -0.591602 0.688033 )
Epeak [keV] : 87.7225 ( -18.8635 63.3692 )
Norm@50keV : 5.87513E-02 ( -0.028541 0.0682619 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 74.00 using 59 bins.
Reduced chi-squared = 1.32143
# Null hypothesis probability of 5.39e-02 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 2.30678 ( -0.20874 0.20863 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.84014e-07 ( -2.02683e-08 2.04609e-08 ) ergs/cm2
Time-resolved spectra
