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 -0.392 sec. to 48.916 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.25642 ( -0.221323 0.224546 )
Norm@50keV : 1.20549E-03 ( -0.000156342 0.00015608 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.53 using 59 PHA bins.
# Reduced chi-squared = 0.9217 for 57 degrees of freedom
# Null hypothesis probability = 6.430922e-01
Photon flux (15-150 keV) in 49.31 sec: 0.142728 ( -0.018802 0.018835 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.93969e-07 ( -8.59902e-08 8.69966e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.392 sec. to 48.916 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.756874 ( -0.670011 1.09284 )
Epeak [keV] : 127.875 ( -57.2748 -127.874 )
Norm@50keV : 2.12987E-03 ( -0.00104658 0.00502338 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.61 using 59 PHA bins.
# Reduced chi-squared = 0.9217 for 56 degrees of freedom
# Null hypothesis probability = 6.414416e-01
Photon flux (15-150 keV) in 49.31 sec: 0.139783 ( -0.019659 0.01956 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.71365e-07 ( -9.66915e-08 9.57723e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.816 sec. to 2.816 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.20735 ( -0.26328 0.268923 )
Norm@50keV : 7.49900E-03 ( -0.00118294 0.0011808 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.15 using 59 PHA bins.
# Reduced chi-squared = 1.020 for 57 degrees of freedom
# Null hypothesis probability = 4.328866e-01
Photon flux (15-150 keV) in 1 sec: 0.881153 ( -0.140406 0.140597 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.59329e-08 ( -1.34228e-08 1.36139e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.816 sec. to 2.816 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.636364 ( -0.911124 1.46262 )
Epeak [keV] : 120.411 ( -56.6719 -120.427 )
Norm@50keV : 1.45716E-02 ( -0.00802312 0.0650766 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.33 using 59 PHA bins.
# Reduced chi-squared = 1.024 for 56 degrees of freedom
# Null hypothesis probability = 4.254969e-01
Photon flux (15-150 keV) in 1 sec: 0.863229 ( -0.146032 0.144891 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.24303e-08 ( -1.56523e-08 1.51467e-08 ) ergs/cm2
Time-resolved spectra
