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 2.160 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.29353 ( -0.142544 0.142678 )
Norm@50keV : 1.06286E-02 ( -0.000895389 0.000893371 )
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#Fit statistic : Chi-Squared = 61.90 using 59 PHA bins.
# Reduced chi-squared = 1.086 for 57 degrees of freedom
# Null hypothesis probability = 3.057006e-01
Photon flux (15-150 keV) in 2.552 sec: 1.26653 ( -0.10744 0.10754 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.68491e-07 ( -2.53596e-08 2.55927e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.392 sec. to 2.160 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.842168 ( -0.504006 0.591446 )
Epeak [keV] : 134.748 ( -49.4965 -134.75 )
Norm@50keV : 1.76261E-02 ( -0.00735423 0.0156528 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.72 using 59 PHA bins.
# Reduced chi-squared = 1.066 for 56 degrees of freedom
# Null hypothesis probability = 3.422513e-01
Photon flux (15-150 keV) in 2.552 sec: 1.24402 ( -0.11078 0.11068 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.60825e-07 ( -2.72311e-08 2.72207e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.012 sec. to 2.012 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.33261 ( -0.144909 0.144046 )
Norm@50keV : 1.76342E-02 ( -0.00155481 0.00155066 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.95 using 59 PHA bins.
# Reduced chi-squared = 1.140 for 57 degrees of freedom
# Null hypothesis probability = 2.193059e-01
Photon flux (15-150 keV) in 1 sec: 2.11699 ( -0.18503 0.18513 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.72934e-07 ( -1.71259e-08 1.72964e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.012 sec. to 2.012 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.712934 ( -0.565095 0.645938 )
Epeak [keV] : 106.750 ( -31.4806 415.43 )
Norm@50keV : 3.58361E-02 ( -0.0167576 0.0371979 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.40 using 59 PHA bins.
# Reduced chi-squared = 1.096 for 56 degrees of freedom
# Null hypothesis probability = 2.887643e-01
Photon flux (15-150 keV) in 1 sec: 2.07194 ( -0.1901 0.18986 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.66184e-07 ( -1.84331e-08 1.84918e-08 ) ergs/cm2
Time-resolved spectra
