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 -1.072 sec. to 325.420 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.99132 ( -0.14771 0.142559 )
Norm@50keV : 7.06841E-04 ( -6.71842e-05 6.60973e-05 )
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#Fit statistic : Chi-Squared = 69.28 using 59 PHA bins.
# Reduced chi-squared = 1.215 for 57 degrees of freedom
# Null hypothesis probability = 1.275057e-01
Photon flux (15-150 keV) in 326.5 sec: 0.105613 ( -0.0081713 0.008176 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.12766e-06 ( -1.90514e-07 1.93326e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.072 sec. to 325.420 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.43213 ( -0.646413 0.784288 )
Epeak [keV] : 42.1252 ( -34.1037 -42.1235 )
Norm@50keV : 1.48817E-03 ( -0.000846644 0.00276554 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.18 using 59 PHA bins.
# Reduced chi-squared = 1.200 for 56 degrees of freedom
# Null hypothesis probability = 1.455662e-01
Photon flux (15-150 keV) in 326.5 sec: 0.103119 ( -0.008709 0.008667 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.00149e-06 ( -2.32343e-07 2.4081e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 24.084 sec. to 25.084 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.6402 ( -0.37413 0.361876 )
Norm@50keV : 7.28116E-03 ( -0.00169936 0.00167115 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.60 using 59 PHA bins.
# Reduced chi-squared = 0.9403 for 57 degrees of freedom
# Null hypothesis probability = 6.034373e-01
Photon flux (15-150 keV) in 1 sec: 0.947728 ( -0.213835 0.214342 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.77969e-08 ( -1.64399e-08 1.66454e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 24.084 sec. to 25.084 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.01965 ( -0.951427 1.90593 )
Epeak [keV] : 75.7860 ( )
Norm@50keV : 1.55332E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.06 using 59 PHA bins.
# Reduced chi-squared = 0.9474 for 56 degrees of freedom
# Null hypothesis probability = 5.870442e-01
Photon flux (15-150 keV) in 1 sec: 0.933452 ( -0.216933 0.217038 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.53266e-08 ( -1.73544e-08 1.76164e-08 ) ergs/cm2
Time-resolved spectra
