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 -1.208 sec. to 224.200 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.54212 ( -0.131272 0.129692 )
Norm@50keV : 1.09259E-03 ( -8.63192e-05 8.5814e-05 )
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#Fit statistic : Chi-Squared 52.34 using 59 bins.
Reduced chi-squared = 0.918246
# Null hypothesis probability of 6.50e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 225.4 sec: 0.138006 ( -0.010475 0.010483 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.32137e-06 ( -1.99623e-07 2.01841e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.208 sec. to 224.200 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.637833 ( -0.575051 0.659982 )
Epeak [keV] : 72.3096 ( -13.5687 43.548 )
Norm@50keV : 3.21493E-03 ( -0.00157032 0.00374097 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 44.64 using 59 bins.
Reduced chi-squared = 0.797143
# Null hypothesis probability of 8.63e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 225.4 sec: 0.132342 ( -0.011049 0.011049 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.14894e-06 ( -2.20242e-07 2.25954e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.276 sec. to 5.276 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -0.742282 ( -0.220316 0.233725 )
Norm@50keV : 1.06849E-02 ( -0.00150641 0.00148203 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 63.05 using 59 bins.
Reduced chi-squared = 1.10614
# Null hypothesis probability of 2.71e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.23142 ( -0.16577 0.16654 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28009e-07 ( -1.74205e-08 1.74866e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.276 sec. to 5.276 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.668976 ( -1.20363 1.71753 )
Epeak [keV] : 117.054 ( -32.5497 282.742 )
Norm@50keV : 3.95915E-02 ( -0.0395939 0.134366 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 58.91 using 59 bins.
Reduced chi-squared = 1.05196
# Null hypothesis probability of 3.69e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.16766 ( -0.177146 0.17648 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21719e-07 ( -1.96086e-08 1.90477e-08 ) ergs/cm2
Time-resolved spectra
