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 -31.736 sec. to 16.188 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.88558 ( -0.0795395 0.0783511 )
Norm@50keV : 8.08435E-03 ( -0.000352067 0.000349383 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.76 using 59 PHA bins.
# Reduced chi-squared = 1.031 for 57 degrees of freedom
# Null hypothesis probability = 4.108939e-01
Photon flux (15-150 keV) in 47.92 sec: 1.15322 ( -0.04639 0.04656 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.56194e-06 ( -1.53649e-07 1.54667e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -31.736 sec. to 16.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.76577 ( -0.27596 0.301422 )
Epeak [keV] : 92.4662 ( )
Norm@50keV : 9.32911E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.25 using 59 PHA bins.
# Reduced chi-squared = 1.040 for 56 degrees of freedom
# Null hypothesis probability = 3.927057e-01
Photon flux (15-150 keV) in 47.92 sec: 1.14314 ( -0.05186 0.05183 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.888 sec. to 5.888 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.7063 ( -0.120328 0.117795 )
Norm@50keV : 3.74401E-02 ( -0.00273936 0.00271022 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.46 using 59 PHA bins.
# Reduced chi-squared = 1.113 for 57 degrees of freedom
# Null hypothesis probability = 2.592563e-01
Photon flux (15-150 keV) in 1 sec: 4.98367 ( -0.32754 0.32769 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.46537e-07 ( -2.65886e-08 2.68765e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.888 sec. to 5.888 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.37497 ( -0.396701 0.498777 )
Epeak [keV] : 86.6245 ( -28.7862 -86.6245 )
Norm@50keV : 5.65792E-02 ( -0.0208581 0.0478474 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.88 using 59 PHA bins.
# Reduced chi-squared = 1.105 for 56 degrees of freedom
# Null hypothesis probability = 2.741830e-01
Photon flux (15-150 keV) in 1 sec: 4.91075 ( -0.34179 0.34164 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
