Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems", 2011.
astro-ph/1108.0997

For a PDF version of the article, click here.

A REVIEW OF ELLIPTICAL AND DISC GALAXY STRUCTURE, AND MODERN SCALING LAWS

Alister W. Graham


Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia.


Abstract: A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These `redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.


Keywords : galaxy structure - galaxy scaling relations - galaxy elliptical - galaxy spiral - galaxy compact - galaxy cD, halos - galaxy nuclei - galaxy central mass deficits - galaxy excess nuclear light - galaxy bulge-disc ratios - galaxy bars - galaxy pseudobulges - galaxy bulgeless - galaxy dust - Sérsic model - core-Sérsic model - Einasto model - dark matter halos.


Table of Contents

INTRODUCTION
Early Beginnings
The modern galaxy

ELLIPTICAL GALAXY LIGHT PROFILES
Sérsic's model
The core-Sérsic model
Excess nuclear light
Excess halo light

STRUCTURE RELATED SCALING RELATIONS
Linear relations
Curved relations
Broken relations

DISC GALAXY LIGHT PROFILES

SUMMARY

REFERENCES

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