Voigt function for modeling emission.
This model uses an EmissionGaussian component to model the core of the profile and an EmissionLorentz component to model the wings of the emission feature. It is for use when the independent axis is in Angstroms.
>>> create_model_component("emissionvoigt", "mdl") >>> print(mdl)
Create a component of the emissionvoigt model and display its default parameters. The output is:
mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.center frozen 5000 1.17549e-38 3.40282e+38 angstroms mdl.flux thawed 1 -3.40282e+38 3.40282e+38 mdl.fwhm thawed 100 1.17549e-38 3.40282e+38 km/s mdl.lg frozen 1 1.17549e-38 3.40282e+38
The attributes for this object are:
The center of the profile, in Angstroms.
The flux the profile. This is the value used for each of the Gaussian and Lorentz sub-components.
The full-width half-maximum of the model in km/s.
The fwhm parameters of the Gaussian and Lorentz components are set based on the fwhm and lg values: the Gaussian component has its fwhm parameter set equal to fwhm , and the Lorentz component has its fwhm parameter set to lg * fwhm .
The Voigt function is approximated by the sum of a Gaussian and a Lorentzian profile (  ), which works best when the ratio between the FWHM of the Gaussian and Lorentzian sub-components is near unity. The flux value is always kept evenly divided in between each sub-component. The FWHM of each sub-component is related to that of the other sub-component via the lg parameter.
-  Lang, Astrophysical Formulae, 1980, 2nd ed., page 220
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