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 -0.756 sec. to 37.096 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.62314 ( -0.116286 0.115142 )
Norm@50keV : 4.68594E-03 ( -0.000312567 0.000311 )
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#Fit statistic : Chi-Squared = 55.23 using 59 PHA bins.
# Reduced chi-squared = 0.9689 for 57 degrees of freedom
# Null hypothesis probability = 5.418840e-01
Photon flux (15-150 keV) in 37.85 sec: 0.606583 ( -0.04022 0.040287 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.65446e-06 ( -1.1738e-07 1.18164e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.756 sec. to 37.096 sec.
Spectral model in the cutoff power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.51887 ( -0.209864 0.436629 )
Epeak [keV] : 229.627 ( -229.629 -229.629 )
Norm@50keV : 5.29553E-03 ( -0.00128878 0.00341516 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.04 using 59 PHA bins.
# Reduced chi-squared = 0.9828 for 56 degrees of freedom
# Null hypothesis probability = 5.113657e-01
Photon flux (15-150 keV) in 37.85 sec: 0.603508 ( -0.041902 0.041861 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.03485e-06 ( -1.59346e-07 1.5195e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 8.640 sec. to 9.640 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.37694 ( -0.273358 0.270636 )
Norm@50keV : 1.21225E-02 ( -0.00196005 0.00195783 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.73 using 59 PHA bins.
# Reduced chi-squared = 1.188 for 57 degrees of freedom
# Null hypothesis probability = 1.562446e-01
Photon flux (15-150 keV) in 1 sec: 1.46878 ( -0.24495 0.24592 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.17717e-07 ( -2.06034e-08 2.07639e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.640 sec. to 9.640 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.530363 ( -0.962911 1.4322 )
Epeak [keV] : 99.0331 ( -29.53 -99.0722 )
Norm@50keV : 2.90880E-02 ( -0.0180585 0.0838093 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.97 using 59 PHA bins.
# Reduced chi-squared = 1.178 for 56 degrees of freedom
# Null hypothesis probability = 1.701442e-01
Photon flux (15-150 keV) in 1 sec: 1.41316 ( -0.2586 0.25708 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.14665e-07 ( -2.10706e-08 2.12414e-08 ) ergs/cm2
Time-resolved spectra
