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 -37.532 sec. to 72.048 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.57218 ( -0.0507197 0.0506632 )
Norm@50keV : 7.60179E-03 ( -0.000199154 0.000199078 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.43 using 59 PHA bins.
# Reduced chi-squared = 1.183 for 57 degrees of freedom
# Null hypothesis probability = 1.623846e-01
Photon flux (15-150 keV) in 109.6 sec: 0.968663 ( -0.027673 0.027758 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.82043e-06 ( -2.17334e-07 2.17986e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -37.532 sec. to 72.048 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.32359 ( -0.203136 0.213145 )
Epeak [keV] : 142.290 ( -42.4741 343.555 )
Norm@50keV : 9.98325E-03 ( -0.00194654 0.00256162 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.04 using 59 PHA bins.
# Reduced chi-squared = 1.126 for 56 degrees of freedom
# Null hypothesis probability = 2.413758e-01
Photon flux (15-150 keV) in 109.6 sec: 0.950201 ( -0.031175 0.031283 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.6565e-06 ( -2.5533e-07 2.543e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 18.332 sec. to 19.332 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.38251 ( -0.173647 0.173055 )
Norm@50keV : 1.90590E-02 ( -0.00196035 0.00195085 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.58 using 59 PHA bins.
# Reduced chi-squared = 0.8875 for 57 degrees of freedom
# Null hypothesis probability = 7.128979e-01
Photon flux (15-150 keV) in 1 sec: 2.31203 ( -0.23325 0.23339 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.84854e-07 ( -2.13757e-08 2.16412e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 18.332 sec. to 19.332 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.967915 ( -0.541339 0.77994 )
Epeak [keV] : 121.704 ( )
Norm@50keV : 3.12301E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.48 using 59 PHA bins.
# Reduced chi-squared = 0.8836 for 56 degrees of freedom
# Null hypothesis probability = 7.183434e-01
Photon flux (15-150 keV) in 1 sec: 2.27308 ( -0.24241 0.24176 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.78057e-07 ( -2.42238e-08 2.42123e-08 ) ergs/cm2
Time-resolved spectra
