2008/11/27 by И. Д. Караченцев, I. D. Karachentsev, O. G. Kashibadze +3 · 1 citation
Physics and Astronomy · #Astrophysics and Star Formation Studies #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.14300.x
14 pages, 6 figures, 1 table. Accepted for publication in MNRAS
arxiv created 2008/11/27 · openalex publication_date 2009/02/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We use updated data on distances and velocities of galaxies in the proximity of the Local Group (LG) in order to establish properties of the local Hubble flow. For 30 neighbouring galaxies with distances 0.7 < DLG < 3.0 Mpc, the local flow is characterized by the Hubble parameter Hloc= (78 ± 2) km s−1 Mpc−1, the mean-square peculiar velocity σv= 25 km s−1, corrected for errors of radial velocity measurements (∼4 km s−1) and distance measurements (∼10 km s−1), as well as the radius of the zero-velocity surface R0= (0.96 ± 0.03) Mpc. The minimum value for σv is achieved when the barycentre of the LG is located at the distance Dc= (0.55 ± 0.05) DM31 towards Andromeda galaxy (M31) corresponding to the Milky Way (MW)-to-M31 mass ratio MMW/MM31≃ 4/5. In the reference frame of the 30 galaxies at 0.7–3.0 Mpc, the LG barycentre has a small peculiar velocity ∼(24 ± 4) km s−1 towards the Sculptor constellation. The derived value of R0 corresponds to the total mass MT(LG) = (1.9 ± 0.2) 1012 M⊙ with Ωm= 0.24 and a topologically flat universe, a value in good agreement with the sum of virial mass estimates for the MW and M31.