2010/12/01 by Xiaolei Zhang, Zhang, Xiaolei, R. Buta +2
Physics and Astronomy · #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.48550/arxiv.1012.0277
10 pages, 7 figures, invited talk presented at meeting "Dynamics and Evolution of Disc Galaxies" held in Moscow and Pushchino, Russia, May 31 - June 4th, 2010
openalex publication_date 2010/12/01 · arxiv created 2012/03/07 · arxiv updated 2012/03/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
In the past two decades, secular evolution has emerged as an important new paradigm for the formation and evolution of the Hubble sequence of galaxies. A new dynamical mechanism was identified through which density waves in galaxies, in the forms of nonlinear and global spiral and bar modes, induce important collective dissipation effects previously unknown in traditional studies. These effects lead to the evolution of the basic state of the galactic disk, consistent with the gradual transformation of a typical galaxy's morphological type from a late to an early Hubble type. In this paper, we review the theoretical framework and highlight our recent result which showed that there are significant qualitative and quantitative differences between the secular evolution rates predicted by the new theory compared with those predicted by the classical approach of Lynden-Bell and Kalnajs. These differences are the outward manifestation of the dominant role played by collisionless shocks in disk galaxies hosting quasi-stationary, extremely non-linear density-wave modes.