2006/10/17 by Victor P. Debattista, Juntai Shen
Physics and Astronomy · #Amplitude #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #High resolution #Primary (astronomy) #Rotation (mathematics) #Work (physics) #astro-ph
paper · pdf · doi:10.1086/511264
published as Astrophys.J.654:L127-L130,2007 · Paper submitted to ApJL
arxiv created 2006/10/17 · openalex publication_date 2006/12/28 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A large fraction of barred galaxies host secondary bars that are embedded in their large-scale primary counterparts. The evolution of such double-barred galaxies is still not well understood, partly because of a lack of realistic N -body models with which to study them. Here we report a new mechanism for generating such systems, namely, the presence of rotating pseudobulges. We demonstrate with high mass and force resolution collisionless N -body simulations that long-lived secondary bars can form spontaneously without requiring gas, contrary to previous claims. We find that secondary bars rotate faster than primary ones. The rotation is not rigid: the secondary bars pulsate, with their amplitude and pattern speed oscillating as they rotate through the primary bars. This self-consistent study supports previous work based on orbital analysis in the potential of two rigidly rotating bars. The pulsating nature of secondary bars may have important implications for understanding the central region of double-barred galaxies.