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 -16.504 sec. to 132.676 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.0164 ( -0.150811 0.154898 )
Norm@50keV : 8.42845E-04 ( -7.16296e-05 7.13715e-05 )
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#Fit statistic : Chi-Squared = 57.60 using 59 PHA bins.
# Reduced chi-squared = 1.011 for 57 degrees of freedom
# Null hypothesis probability = 4.526863e-01
Photon flux (15-150 keV) in 149.2 sec: 9.71255E-02 ( -0.0084438 0.0084755 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.35216e-06 ( -1.22322e-07 1.23065e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -16.504 sec. to 132.676 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.839032 ( -0.309425 0.624286 )
Epeak [keV] : 378.049 ( -378.049 -378.049 )
Norm@50keV : 1.00959E-03 ( -0.000227436 0.000839901 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.31 using 59 PHA bins.
# Reduced chi-squared = 1.023 for 56 degrees of freedom
# Null hypothesis probability = 4.261556e-01
Photon flux (15-150 keV) in 149.2 sec: 9.63079E-02 ( -0.0088368 0.0088131 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.33958e-06 ( -1.301e-07 1.28936e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -7.856 sec. to -6.856 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.01741 ( -0.372741 0.394405 )
Norm@50keV : 4.01973E-03 ( -0.000906038 0.000903127 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 50.13 using 59 PHA bins.
# Reduced chi-squared = 0.8795 for 57 degrees of freedom
# Null hypothesis probability = 7.284068e-01
Photon flux (15-150 keV) in 1 sec: 0.463246 ( -0.105704 0.106177 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.32056e-08 ( -1.05212e-08 1.06921e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -7.856 sec. to -6.856 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.0703312 ( -1.25964 2.66645 )
Epeak [keV] : 105.184 ( )
Norm@50keV : 1.26381E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.80 using 59 PHA bins.
# Reduced chi-squared = 0.8715 for 56 degrees of freedom
# Null hypothesis probability = 7.414508e-01
Photon flux (15-150 keV) in 1 sec: 0.442542 ( -0.111988 0.110911 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.04045e-08 ( -1.14117e-08 1.16274e-08 ) ergs/cm2
Time-resolved spectra
