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 -13.100 sec. to 10.412 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -2.03736 ( -0.190457 0.179952 )
Norm@50keV : 2.86912E-03 ( -0.00037006 0.000363061 )
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#Fit statistic : Chi-Squared = 60.12 using 59 PHA bins.
# Reduced chi-squared = 1.055 for 57 degrees of freedom
# Null hypothesis probability = 3.634997e-01
Photon flux (15-150 keV) in 23.51 sec: 0.437964 ( -0.045135 0.045154 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.23582e-07 ( -7.44928e-08 7.5717e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -13.100 sec. to 10.412 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.691085 ( -0.89967 1.11993 )
Epeak [keV] : 40.3347 ( -9.08852 9.5967 )
Norm@50keV : 1.71537E-02 ( -0.0171537 0.0597595 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.01 using 59 PHA bins.
# Reduced chi-squared = 0.9466 for 56 degrees of freedom
# Null hypothesis probability = 5.886812e-01
Photon flux (15-150 keV) in 23.51 sec: 0.419472 ( -0.046442 0.046634 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.61466e-07 ( -7.57607e-08 8.20254e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.000 sec. to 1.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.52335 ( -0.112419 0.111949 )
Norm@50keV : 2.94100E-02 ( -0.00210621 0.00210298 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 75.61 using 59 PHA bins.
# Reduced chi-squared = 1.326 for 57 degrees of freedom
# Null hypothesis probability = 5.012357e-02
Photon flux (15-150 keV) in 1 sec: 3.69516 ( -0.27042 0.27084 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.78003e-07 ( -2.11409e-08 2.12304e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 1.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.547763 ( -0.49217 0.550341 )
Epeak [keV] : 75.1860 ( -11.9185 27.1816 )
Norm@50keV : 9.13342E-02 ( -0.0390098 0.0787053 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.03 using 59 PHA bins.
# Reduced chi-squared = 1.126 for 56 degrees of freedom
# Null hypothesis probability = 2.416626e-01
Photon flux (15-150 keV) in 1 sec: 3.58876 ( -0.27575 0.27609 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.64746e-07 ( -2.23084e-08 2.24246e-08 ) ergs/cm2
Time-resolved spectra
