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 -15.000 sec. to 49.000 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.28896 ( -0.300418 0.270033 )
Norm@50keV : 6.05476E-04 ( -0.000131605 0.000129548 )
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#Fit statistic : Chi-Squared = 61.38 using 59 PHA bins.
# Reduced chi-squared = 1.077 for 57 degrees of freedom
# Null hypothesis probability = 3.219588e-01
Photon flux (15-150 keV) in 64 sec: 0.105178 ( -0.0140851 0.014092 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.69641e-07 ( -6.44864e-08 6.76493e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.000 sec. to 49.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.50955 ( -0.826979 1.50891 )
Epeak [keV] : 22.5761 ( -19.3854 14.9369 )
Norm@50keV : 1.89164E-03 ( -0.00108141 0.0157306 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.22 using 59 PHA bins.
# Reduced chi-squared = 1.075 for 56 degrees of freedom
# Null hypothesis probability = 3.255668e-01
Photon flux (15-150 keV) in 64 sec: 0.105400 ( -0.0141073 0.013968 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.38057e-07 ( -6.57619e-08 8.1113e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -7.500 sec. to -6.500 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.15739 ( -1.08746 0.89301 )
Norm@50keV : 1.21692E-03 ( -0.000872113 0.000869417 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.04 using 59 PHA bins.
# Reduced chi-squared = 0.8954 for 57 degrees of freedom
# Null hypothesis probability = 6.972080e-01
Photon flux (15-150 keV) in 1 sec: 0.195904 ( -0.107346 0.108216 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10438e-08 ( -6.75101e-09 8.03276e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -7.500 sec. to -6.500 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 6.44076 ( -6.67693 -6.48918 )
Epeak [keV] : 32.0866 ( -7.14227 8.85436 )
Norm@50keV : 569.343 ( -661.529 215516 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.50 using 59 PHA bins.
# Reduced chi-squared = 0.8126 for 56 degrees of freedom
# Null hypothesis probability = 8.407542e-01
Photon flux (15-150 keV) in 1 sec: 0.207664 ( -0.09389 0.098156 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.86938e-09 ( -4.50326e-09 4.92681e-09 ) ergs/cm2
Time-resolved spectra
