2000/02/29 by M. A. Jalali, Mir Abbas Jalali, A. R. Rafiee +1 · 6 citations
Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Elliptic coordinate system #Galaxy #Geometry #Nucleus #Physics #Quantum chaos and dynamical systems #Quantum mechanics #Rotational symmetry #Spherical coordinate system #Stellar, planetary, and galactic studies #Surface (topology) #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2001.04012.x
published in Monthly Notices of the Royal Astronomical Society 320(3), 379-386 (Oxford University Press) · 8 pages, accepted for publication in MNRAS
arxiv created 2000/09/15 · openalex publication_date 2001/01/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We introduce a new class of 2D mass models, whose potentials are of Stäckel form in elliptic coordinates. Our model galaxies have two separate strong cusps that form double nuclei. The potential and surface density distributions are locally axisymmetric near the nuclei and become highly non-axisymmetric outside the nucleus. The surface density diverges toward the cuspy nuclei with the law ∑ ∝ r−2. Our model is sustained by four general types of regular orbits: butterfly, nucleophilic banana, horseshoe and aligned loop orbits. Horseshoes and nucleophilic bananas support the existence of cuspy regions. Butterflies and aligned loops control the non-axisymmetric shape of outer regions. Without any need for central black holes, our distributed mass models resemble the nuclei of M31 and NGC 4486B. It is also shown that the self-gravity of the stellar disc can prevent the double nucleus to collapse.