An Analysis of 900 Optical Rotation Curves

Abstract

Persic & Salucci (1995; hereafter, PS) reduced raw H_α data from a large sample of southern sky spirals obtained by Mathewson, Ford & Buchhorn (1992), to present 900 H_α, rotation curves. It is found that a power-law, V_rot = A R^α, imposes extremely detailed correlations between the kinematic and the luminous properties of the galaxies through the model parameters (A, α); this law can be inverted to give a form of super Tulley-Fisher relationship for the determination of absolute magnitudes in terms of velocity information. Furthermore, there is very strong evidence suggesting the existence of discrete kinematic states for rotation curves (RCs hereafter) - which ultimately implies the luminosity evolution of galaxies to be similarly constrained to occupy discrete states.