What is pseudo Voigt?
The pseudo-Voigt profile (or pseudo-Voigt function) is an approximation of the Voigt profile V(x) using a linear combination of a Gaussian curve G(x) and a Lorentzian curve L(x) instead of their convolution. The pseudo-Voigt function is often used for calculations of experimental spectral line shapes.
What is a Lorentz profile?
Lorentz Profiles (Natural damping): Emission and absorption features always display a finite width, the natural damping profile widened by the effects of motion and by observational effects (seeing conditions, resolution of equipment).
What is pressure broadening in spectroscopy?
Pressure broadening refers to the collisional interaction between the atoms absorbing light and other particles, mainly protons and electrons, in hot stars with Teff>9000K.
What is Lorentzian signature?
A Lorentzian metric is a metric with signature (p, 1), or (1, p). There is another notion of signature of a nondegenerate metric tensor given by a single number s defined as (v − p), where v and p are as above, which is equivalent to the above definition when the dimension n = v + p is given or implicit.
Which is better a Gaussian function or a Lorentzian function?
The Lorentzian function has more pronounced tails than a corresponding Gaussian function, and since this is the natural form of the solution to the differential equation describing a damped harmonic oscillator, I think it should be used in all physics concerned with such oscillations, i.e. natural line widths, plasmon oscillations etc.
What causes a Lorentzian peak to broaden out?
This can cause the peak to broaden by both Gaussian and Lorentzian mechanisms. Voigt lineshape data. You can see how the peak is more pointed, which is a feature of a Lorentzian peak, whereas as you get closer to the baseline, the peak broadens out, a feature of Gaussian curves (i.e. normal distributions).
Can a Lorentz profile be used for a strong oscillator?
We did this recently and found that a Lorentz-profile must not be used for strong oscillators, is sometimes questionable for medium strong oscillators and works excellent for weak oscillators: Article Quantitative Evaluation of Infrared Absorbance Spectra – Lor…
Can a Gaussian curve fit multiple overlapping peaks?
It is extremely helpful to be able to fit several overlapping peaks, because usually spectral features are not well-resolved from one another, and even a portion of the tail of a gaussian curve can skew the fit of another curve if they are overlapping. We will consider a strongly overlapping region of data: