2002/07/31 by Maarten Baes, M. Baes, H. Dejonghe +1 · 2 citations
Mathematics · Physics and Astronomy · #Anisotropy #Astronomy and Astrophysical Research #Computer science #Constant (computer programming) #Distribution (mathematics) #Distribution function #Galaxies: Formation, Evolution, Phenomena #Isotropy #Materials science #Mathematical analysis #Mathematics #Monte Carlo method #Physics #Quantum mechanics #Range (aeronautics) #Simple (philosophy) #Statistical physics #Statistics #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20021064
published as Astron.Astrophys. 393 (2002) 485-498 · 14 pages, 7 figures, accepted for publication in A&A - formulae (51) and (54) and figure 4 corrected
arxiv created 2002/08/03 · openalex publication_date 2002/09/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Simple analytical models, such as the Hernquist model, are very useful tools to investigate the dynamical structure of galaxies. Unfortunately, most of the analytical distribution functions are either isotropic or of the Osipkov-Merritt type, and hence basically one-dimensional. We present three different families of anisotropic distribution functions that self-consistently generate the Hernquist potential-density pair. These families have constant, increasing and decreasing anisotropy profiles respectively, and can hence represent a wide variety of orbital structures. For all of the models presented, the distribution function and the velocity dispersions can be written in terms of elementary functions. These models are ideal tools for a wide range of applications, in particular to generate the initial conditions for N-body or Monte Carlo simulations.