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Paper: Variable Mass Structure and the Fundamental Plane
Volume: 117, Dark and Visible Matter in Galaxies
Page: 172
Authors: Graham, A.; Colless, M.
Abstract: We examine the influence of broken structural homology upon the Fundamental Plane (FP). We fit the Sersic R1/n law, being the generalized R1/4 law, where `n' is a free parameter that accommodates structural differences between different galaxies. The galaxy light profiles show a trend of systematic departures from the de Vaucouleurs R1/4 law, such that the larger galaxies have less curvature in their profiles than the R1/4 profile and the smaller galaxies have greater curvature, as found by Caon, Capaccioli & D'Onofrio (1993) and Graham et al. (1996). This results in the effective half-light radii, Re, and the mean surface brightness within these radii, having systematic biases if obtained from the R1/4 law. The observed range in structural shapes implies a corresponding range in galaxy dynamics required to support the observed galaxy structure. Allowing for this, we find that broken structural and dynamical homology are partly responsible for the `tilt' of the FP.
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