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 -0.028 sec. to 14.972 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.77266 ( -0.131438 0.12854 )
Norm@50keV : 4.43238E-03 ( -0.000363907 0.000360102 )
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#Fit statistic : Chi-Squared = 46.64 using 59 PHA bins.
# Reduced chi-squared = 0.8183 for 57 degrees of freedom
# Null hypothesis probability = 8.345749e-01
Photon flux (15-150 keV) in 15 sec: 0.604448 ( -0.045036 0.045072 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.1286e-07 ( -5.14609e-08 5.20174e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.028 sec. to 14.972 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.04567 ( -0.549155 0.629082 )
Epeak [keV] : 59.5825 ( -11.261 44.8546 )
Norm@50keV : 1.10122E-02 ( -0.00538645 0.0129789 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 41.35 using 59 PHA bins.
# Reduced chi-squared = 0.7383 for 56 degrees of freedom
# Null hypothesis probability = 9.283549e-01
Photon flux (15-150 keV) in 15 sec: 0.586432 ( -0.047017 0.047012 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.75124e-07 ( -5.71579e-08 5.85432e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.760 sec. to 3.760 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.81961 ( -0.258038 0.243769 )
Norm@50keV : 8.46667E-03 ( -0.00146777 0.00143137 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.25 using 59 PHA bins.
# Reduced chi-squared = 0.9868 for 57 degrees of freedom
# Null hypothesis probability = 5.032577e-01
Photon flux (15-150 keV) in 1 sec: 1.17574 ( -0.17157 0.1716 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.79094e-08 ( -1.34316e-08 1.37211e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.760 sec. to 3.760 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.929266 ( -1.00837 1.36922 )
Epeak [keV] : 51.4799 ( -15.3408 -51.48 )
Norm@50keV : 2.73814E-02 ( -0.0273814 0.141013 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.16 using 59 PHA bins.
# Reduced chi-squared = 0.9672 for 56 degrees of freedom
# Null hypothesis probability = 5.446295e-01
Photon flux (15-150 keV) in 1 sec: 1.15009 ( -0.174238 0.17429 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.2124e-08 ( -1.40636e-08 1.5145e-08 ) ergs/cm2
Time-resolved spectra
