Open AccessIntegrable models of galactic discs with double nuclei
Author(s) -
Jalali M. A.,
Rafiee A. R.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04012.x
Subject(s) - physics , rotational symmetry , galaxy , elliptic coordinate system , astrophysics , nucleus , surface (topology) , geometry , quantum mechanics , spherical coordinate system , mathematics , mechanics , biology , microbiology and biotechnology
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 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.