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 -17.768 sec. to 23.232 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.21362 ( -0.0766446 0.0772474 )
Norm@50keV : 1.98034E-02 ( -0.00085971 0.000858736 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.28 using 59 PHA bins.
# Reduced chi-squared = 0.9347 for 57 degrees of freedom
# Null hypothesis probability = 6.155090e-01
Photon flux (15-150 keV) in 41 sec: 2.32908 ( -0.10728 0.10749 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.20697e-06 ( -3.76752e-07 3.77705e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -17.768 sec. to 23.232 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.1178 ( -0.0994549 0.303675 )
Epeak [keV] : 490.300 ( -594.613 -779.036 )
Norm@50keV : 2.18785E-02 ( -0.00195193 0.00731078 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.30 using 59 PHA bins.
# Reduced chi-squared = 0.9518 for 56 degrees of freedom
# Null hypothesis probability = 5.777756e-01
Photon flux (15-150 keV) in 41 sec: 2.32252 ( -0.11115 0.10995 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.18585e-06 ( -3.90716e-07 3.87758e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.768 sec. to 0.232 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.909447 ( -0.110962 0.112733 )
Norm@50keV : 0.161848 ( -0.0111241 0.0110876 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.67 using 59 PHA bins.
# Reduced chi-squared = 1.205 for 57 degrees of freedom
# Null hypothesis probability = 1.383290e-01
Photon flux (15-150 keV) in 1 sec: 0.764954 0.845180 0.676463 0.537979 0.432872 0.355042 0.298362 0.257393 0.227734 0.206071 0.190024 0.177934 0.168659 0.161413 0.155654 0.151003 0.147191 0.144025 0.141363 0.139101 0.137159 0.135477 0.134009 0.132718 0.130565 0.128836 0.127414 0.125144 0.123385 0.122011 0.120105 0.113918 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.80992e-06 ( -1.34707e-07 1.35261e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.768 sec. to 0.232 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.412435 ( -0.464939 0.517775 )
Epeak [keV] : 184.018 ( -65.8828 812.516 )
Norm@50keV : 0.271523 ( -0.101417 0.184516 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.36 using 59 PHA bins.
# Reduced chi-squared = 1.167 for 56 degrees of freedom
# Null hypothesis probability = 1.836086e-01
Photon flux (15-150 keV) in 1 sec: 18.4053 ( -1.2902 1.29 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.78217e-06 ( -1.409e-07 1.40125e-07 ) ergs/cm2
Time-resolved spectra
