1996/01/19 by Luca Ciotti, L. Ciotti, B. Lanzoni +1 · 6 citations
Physics and Astronomy · #Anisotropy #Astronomy and Astrophysical Research #Astrophysics #Dark matter #Elliptical galaxy #Fundamental plane (elliptical galaxies) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Geometry #Lenticular galaxy #Optics #Physics #Plane (geometry) #Stellar, planetary, and galactic studies #Tilt (camera) #Velocity dispersion #astro-ph
paper · pdf · doi:10.1093/mnras/282.1.1
12 pages MNRAS-TeX (mn.tex v1.5 incl.), 6 figures (.ps included) uuencoded, gzip'ed tar file, accepted by MNRAS
arxiv created 1996/01/19 · openalex publication_date 1996/09/01 · arxiv updated 2015/06/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In this paper we explore several structural and dynamical effects on the projected velocity dispersion as possible causes of the fundamental plane (FP) tilt of elliptical galaxies. Specifically, we determine the size of the systematic trend along the FP in the orbital radial anisotropy, in the dark matter (DM) content and distribution relative to the bright matter, and in the shape of the light profile that would be needed to produce the tilt, under the assumption of a constant stellar mass-to-light ratio. Spherical, non-rotating, two-component models are constructed, where the light profiles resemble the R1/4 law. For the investigated models anisotropy cannot play a major role in causing the tilt, while a systematic increase in the DM content and/or concentration may formally produce it. Also a suitable variation of the shape of the light profile can produce the desired effect, and there may be some observational hints supporting this possibility. However, fine tuning is always required in order to produce the tilt, while preserving the tightness of the distribution of the galaxies about the FP.