2005/11/30 by X. Hernandez, X. Hernández, Bernardo Cervantes Sodi +1 · 1 citation
Physics and Astronomy · #Galaxies: Formation, Evolution, Phenomena #Scientific Research and Discoveries #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.10115.x
published as Mon.Not.Roy.Astron.Soc.368:351-360,2006 · 10 pages including 11 figures, Final version, MNRAS in press
arxiv created 2006/02/25 · openalex publication_date 2006/03/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present a highly simplified model of the dynamical structure of a disc galaxy where only two parameters fully determine the solution, mass and angular momentum. We show through simple physical scalings that once the mass has been fixed, the angular momentum parameter λ is expected to regulate such critical galactic disc properties as colour, thickness of the disc and bulge-to-disc ratio. It is, hence, expected to be the determinant physical ingredient resulting in a given Hubble type. A simple analytic estimate of λ for an observed system is provided. An explicit comparison of the distribution of several galactic parameters against both Hubble type and λ is performed using observed galaxies. Both such distributions exhibit highly similar characteristics for all galactic properties studied, suggesting λ as a physically motivated classification parameter for disc galaxies.