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 -15.528 sec. to 64.472 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.52763 ( -0.0638722 0.063741 )
Norm@50keV : 1.09966E-02 ( -0.000393015 0.000392946 )
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#Fit statistic : Chi-Squared = 62.80 using 59 PHA bins.
# Reduced chi-squared = 1.102 for 57 degrees of freedom
# Null hypothesis probability = 2.782439e-01
Photon flux (15-150 keV) in 80 sec: 1.38330 ( -0.05361 0.05377 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.3104e-06 ( -3.12794e-07 3.13227e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.528 sec. to 64.472 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.07523 ( -0.259889 0.275825 )
Epeak [keV] : 111.630 ( -23.0752 73.9955 )
Norm@50keV : 1.78340E-02 ( -0.0042207 0.00591566 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.60 using 59 PHA bins.
# Reduced chi-squared = 0.9572 for 56 degrees of freedom
# Null hypothesis probability = 5.661448e-01
Photon flux (15-150 keV) in 80 sec: 1.34493 ( -0.0574 0.05767 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.10736e-06 ( -3.36484e-07 3.35702e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 39.972 sec. to 40.972 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.65234 ( -0.0681368 0.0676115 )
Norm@50keV : 7.14941E-02 ( -0.00292308 0.00291766 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.06 using 59 PHA bins.
# Reduced chi-squared = 1.019 for 57 degrees of freedom
# Null hypothesis probability = 4.358590e-01
Photon flux (15-150 keV) in 1 sec: 9.34293 ( -0.39051 0.39112 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.6486e-07 ( -2.84749e-08 2.85498e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 39.972 sec. to 40.972 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.944906 ( -0.300518 0.323856 )
Epeak [keV] : 75.3723 ( -9.9638 20.0236 )
Norm@50keV : 0.161494 ( -0.0464146 0.0716631 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 40.38 using 59 PHA bins.
# Reduced chi-squared = 0.7211 for 56 degrees of freedom
# Null hypothesis probability = 9.425012e-01
Photon flux (15-150 keV) in 1 sec: 9.04432 ( -0.40785 0.40847 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.37808e-07 ( -3.10856e-08 3.10132e-08 ) ergs/cm2
Time-resolved spectra
