2006/02/14 by F. Combes, Combes, F.
Energy · Physics and Astronomy · #Astro and Planetary Science #Astrophysics (astro-ph) #FOS: Physical sciences #Global Energy and Sustainability Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0602300
4 pages, no figure, invited talk to the 11th Latin American Regional IAU meeting, Pucon, Chile 2005
arxiv created 2006/02/14 · openalex publication_date 2006/02/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Except in the most extreme cases of nuclear activity, either starbursts or AGN, it is difficult to find observationnally a close link between the dynamics and the activity. Theoretically however, the necessary step to fuel the gas to the center, is that gravity torques are created through a non-axisymmetric pattern, either bar and/or spiral, triggered or not by a tidal interaction. We describe the sequence of processes for a typical evolution cycle for a spiral galaxy, and the possible efficient feedback mechanisms. The various morphologies and dynamical states of spiral galaxies are interpreted in terms of a sequence of evolutionary phases, and the corresponding time-scales can be estimated from observations. In this scenario, activity in galaxies is related to the appearance of bar instability, although they might not be synchronised in phase. The role of external gas accretion in the secular evolution is discussed.