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 -13.516 sec. to 216.956 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23274 ( -0.0657686 0.0662291 )
Norm@50keV : 2.24719E-03 ( -7.9824e-05 7.97929e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.31 using 59 PHA bins.
# Reduced chi-squared = 0.9703 for 57 degrees of freedom
# Null hypothesis probability = 5.388897e-01
Photon flux (15-150 keV) in 230.5 sec: 0.265056 ( -0.009987 0.010007 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.20835e-06 ( -1.99933e-07 2.0057e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -13.516 sec. to 216.956 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.13378 ( -0.128839 0.251087 )
Epeak [keV] : 484.894 ( -485.207 -485.207 )
Norm@50keV : 2.49465E-03 ( -0.000411368 0.000728789 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.81 using 59 PHA bins.
# Reduced chi-squared = 0.9788 for 56 degrees of freedom
# Null hypothesis probability = 5.199533e-01
Photon flux (15-150 keV) in 230.5 sec: 0.263525 ( -0.010622 0.00516 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.17429e-06 ( -2.17036e-07 2.11398e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 27.440 sec. to 28.440 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.23922 ( -0.428356 0.445951 )
Norm@50keV : 5.36306E-03 ( -0.00138334 0.00138204 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.55 using 59 PHA bins.
# Reduced chi-squared = 0.8868 for 57 degrees of freedom
# Null hypothesis probability = 7.141369e-01
Photon flux (15-150 keV) in 1 sec: 0.633220 ( -0.166987 0.167879 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.38319e-08 ( -1.51026e-08 1.54405e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 27.440 sec. to 28.440 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.325896 ( -2.56964 4.56558 )
Epeak [keV] : 71.9028 ( -19.6196 -71.8588 )
Norm@50keV : 3.40860E-02 ( -0.0341984 6.5535 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.31 using 59 PHA bins.
# Reduced chi-squared = 0.8806 for 56 degrees of freedom
# Null hypothesis probability = 7.241283e-01
Photon flux (15-150 keV) in 1 sec: 0.593446 ( -0.181858 0.180244 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.66573e-08 ( -1.69946e-08 1.89995e-08 ) ergs/cm2
Time-resolved spectra
