The self-consistent response of stellar disks to bar forcing

Abstract

view Abstract Citations (21) References (50) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The self-consistent response of stellar disks to bar forcing Thielheim, K. O. ; Wolff, H. Abstract Self-consistent N-body experiments with thin stellar disks are peformed using a set of biorthogonal surface density and potential functions to calculate the gravitational force field. Like in other N-body calculations, regular, global spiral density waves are found in disks that show weak bar instabilities confined to central regions. The experiments are analyzed with particular regard to the angular momentum redistribution in the disk which is related to the development of nonaxisymmetric structures. The chronological correlation between the development of bar structure and the development of spiral structure is interpreted as a causal relationship, which implies the hypothesis of spiral waves in stellar disks excited by the development of central bars. This hypothesis is confirmed by means of N-body experiments in which an external oval distortion is slowly imposed in an otherwise stable axisymmetric disk. The resulting regular, two-armed, trailing spiral patterns are in agreement with those found in the unperturbed N-body experiments, particularly with regard to the shape and location of the spiral arms, the process of angular momentum transfer, and the lifetime of the spirals. Additional experiments from which the self-gravity of the stellar disk is excluded show virtually unchanged response patterns. Hence, the gravitational interaction of the participating stars is not primarily responsible for the formation of spiral structure. Self-gravity is important only for the development of a central bar which in turn excites the spiral wave. Publication: The Astrophysical Journal Pub Date: January 1984 DOI: 10.1086/161599 Bibcode: 1984ApJ...276..135T Keywords: Barred Galaxies; Density Wave Model; Disk Galaxies; Galactic Structure; Spiral Galaxies; Stellar Motions; Angular Momentum; Celestial Mechanics; Galactic Evolution; Galactic Rotation; Gravitational Fields; Many Body Problem; Star Distribution; Astronomy full text sources ADS |