Tests of the Fourier-quotient method
John B. Laird, Harold F. Levison · The Astronomical Journal · 1985
Tests of the Fourier-quotient method of determining rotation curves and velocity-dispersion profiles of galaxies, were performed in order to determine if the reported velocity dispersions are affected by metallicity. Synthetic spectra were used as templates. The effects of varying [Fe/H] on the velocity dispersion (σ) and "line-strength" parameter (γ) determined by the Fourier-quotient method were studied. Noise was not added to the spectra. The velocity dispersion varies by approximately 15% over the relative metallicity range studied, indicating that a small systematic error will arise due to changing metallicity. The line strength is strongly correlated with [Fe/H] as expected, but is also nearly independent of absolute metallicity.