2015/07/31 by Mattia C. Sormani, James Binney, John Magorrian · 2 citations
Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Atomic physics #Bar (unit) #Computational physics #Flow (mathematics) #Galaxies: Formation, Evolution, Phenomena #Interpretation (philosophy) #Inviscid flow #Magnetic monopole #Mechanics #Meteorology #Milky Way #Parameter space #Physics #Quadrupole #Quantum mechanics #Statistics #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stv2067
accepted for publication in MNRAS. This version corrects a typo in the normalization factor that is present in the published version
openalex publication_date 2015/10/08 · arxiv created 2017/11/02 · arxiv updated 2017/11/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We run hydrodynamical simulations of a 2D isothermal non-self-gravitating inviscid gas flowing in a rigidly rotating externally imposed potential formed by only two components: a monopole and a quadrupole. We explore systematically the effects of varying the quadrupole while keeping fixed the monopole and discuss the consequences for the interpretation of longitude–velocity diagrams in the Milky Way. We find that the gas flow can constrain the quadrupole of the potential and the characteristics of the bar that generates it. The exponential scale length of the bar must be at least 1.5 kpc. The strength of the bar is also constrained. Our global interpretation favours a pattern speed of Ω = 40 km s−1 kpc−1. We find that for most observational features, there exist a value of the parameters that matches each individual feature well, but is difficult to reproduce all the important features at once. Due to the intractably high number of parameters involved in the general problem, quantitative fitting methods that can run automatic searches in parameter space are necessary.