2002/06/17 by F. Bournaud, F. Combes · 12 citations
Physics and Astronomy · #Accretion (finance) #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Bar (unit) #Bulge #Galaxies: Formation, Evolution, Phenomena #Galaxy #Redshift #Spiral (railway) #Spiral galaxy #Star formation #astro-ph
paper · pdf · doi:10.1051/0004-6361:20020920
21 pages, 21 figures. Accepted for publication in A&A. Figs. 1, 2, 5, 10, 14, 15, 19 are available as jpeg files
arxiv created 2002/06/17 · openalex publication_date 2002/08/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The effects of gas accretion on spiral disk dynamics and stability are studied through N-body simulations, including star formation and gas/stars mass exchange. The detailed processes of bar formation, bar destruction and bar re-formation are followed, while in the same time the disk to bulge ratio is varying. The accreted gas might be first prevented to flow inwards to the center by the bar gravity torques, which maintains it to the outer Lindblad resonance. While the first bar is weakening, the accreted gas replenishes the disk, increasing the disk-to-bulge ratio, and the disk self-gravity. A second bar is then unstable, with a higher pattern speed, due both to the increased mass, and shorter bar length. Three or four bar episodes have been followed over a Hubble time. Their strength is decreasing with time, while their pattern speed is increasing. Detailed balance of the angular momentum transfer and evolution can account for these processes. The gas recycled through star formation, and rejected through stellar mass loss plays also a role in the disk dynamics. Implications on the spiral galaxy dynamics and evolution along the Hubble sequence, and as a function of redshift are discussed.