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 22.000 sec. to 147.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.83369 ( -0.130547 0.127401 )
Norm@50keV : 1.30503E-03 ( -0.000102076 0.000100641 )
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#Fit statistic : Chi-Squared = 52.53 using 59 PHA bins.
# Reduced chi-squared = 0.9216 for 57 degrees of freedom
# Null hypothesis probability = 6.432679e-01
Photon flux (15-150 keV) in 125 sec: 0.182244 ( -0.012116 0.012124 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.50061e-06 ( -1.17715e-07 1.19406e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 22.000 sec. to 147.000 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.68999 ( -0.448638 0.506369 )
Epeak [keV] : 95.2508 ( -73.8948 -95.254 )
Norm@50keV : 1.56731E-03 ( -0.00052372 0.0013882 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.25 using 59 PHA bins.
# Reduced chi-squared = 0.9330 for 56 degrees of freedom
# Null hypothesis probability = 6.175748e-01
Photon flux (15-150 keV) in 125 sec: 0.180817 ( -0.012926 0.012887 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.4753e-06 ( -1.41718e-07 1.37721e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 75.000 sec. to 76.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.72637 ( -0.753013 0.681 )
Norm@50keV : 2.48017E-03 ( -0.00115093 0.00108649 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.19 using 59 PHA bins.
# Reduced chi-squared = 1.056 for 57 degrees of freedom
# Null hypothesis probability = 3.612455e-01
Photon flux (15-150 keV) in 1 sec: 0.332502 ( -0.125728 0.12573 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.29229e-08 ( -1.02956e-08 1.12443e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 75.000 sec. to 76.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 9.99879 ( )
Epeak [keV] : 34.1381 ( )
Norm@50keV : 7.97022E+04 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.84 using 59 PHA bins.
# Reduced chi-squared = 0.9435 for 56 degrees of freedom
# Null hypothesis probability = 5.953226e-01
Photon flux (15-150 keV) in 1 sec: 0.274301 ( -0.077792 0.11809 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.38871e-08 ( -3.97924e-09 5.96333e-09 ) ergs/cm2
Time-resolved spectra
