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 -4.928 sec. to 213.820 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.61526 ( -0.11299 0.1118 )
Norm@50keV : 1.26644E-03 ( -8.18131e-05 8.13239e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.09 using 59 PHA bins.
# Reduced chi-squared = 0.8262 for 57 degrees of freedom
# Null hypothesis probability = 8.224058e-01
Photon flux (15-150 keV) in 218.7 sec: 0.163528 ( -0.010214 0.010228 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.58595e-06 ( -1.79325e-07 1.80918e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.928 sec. to 213.820 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.30648 ( -0.361638 0.494011 )
Epeak [keV] : 108.295 ( -40.1689 -108.298 )
Norm@50keV : 1.82967E-03 ( -0.00061789 0.00142592 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.70 using 59 PHA bins.
# Reduced chi-squared = 0.8161 for 56 degrees of freedom
# Null hypothesis probability = 8.354259e-01
Photon flux (15-150 keV) in 218.7 sec: 0.160783 ( -0.010981 0.010928 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.51205e-06 ( -2.08763e-07 2.0876e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 57.176 sec. to 58.176 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.64854 ( -0.492075 0.456172 )
Norm@50keV : 4.66442E-03 ( -0.00134078 0.00125408 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.39 using 59 PHA bins.
# Reduced chi-squared = 0.8490 for 57 degrees of freedom
# Null hypothesis probability = 7.844843e-01
Photon flux (15-150 keV) in 1 sec: 0.608789 ( -0.14645 0.146477 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.3393e-08 ( -1.27614e-08 1.31905e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 57.176 sec. to 58.176 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.30456 ( -0.0387897 1.56492 )
Epeak [keV] : 110.504 ( )
Norm@50keV : 2.11661E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.03 using 59 PHA bins.
# Reduced chi-squared = 0.8576 for 56 degrees of freedom
# Null hypothesis probability = 7.668452e-01
Photon flux (15-150 keV) in 1 sec: 0.463380 ( -0.233356 1.07236 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.837e-08 ( -1.41598e-08 1.39728e-08 ) ergs/cm2
Time-resolved spectra
