Action Dynamics of the Local Supercluster
Abstract
The fully nonlinear gravitationally induced trajectories of a nearly complete set of galaxies, groups, and clusters in the Local Supercluster are constructed in a numerical action method model constrained by data from the CosmicFlows survey and various distance indicators. We add the gravity field due to inhomogeneities external to the sample sphere by making use of largerscale peculiar flow measurements. Assignments of total masses were made to find the best overall set of mutual attractions, as determined by a goodness criterion based on presentday radial velocities, individually for the Virgo Cluster, M31, and the Milky Way (MW), and via a masstolight ratio relationship for other masses. The low median chisquare found indicates that the model fits the presentday velocity flow well, but a slightly high mean chisquare may indicate that some masses underwent complex orbits. The best fit, when setting the value of H _{0} to the CosmicFlows value of 75 km s^{1} Mpc^{1} and the WMAP value for Ω_{ m } = 0.244 consistent with that H _{0}, occurs with the following parameters: Ω_{orphan} = 0.077 ± 0.016, M/{L}_{K}=40+/ 2{L}_{10}^{0.15}{M}_{⊙ }/{L}_{⊙ } (L _{10} is the Kband luminosity in units of 10^{10} L _{⊙}), a Virgo mass of 6.3 ± 0.8 × 10^{14} M _{⊙} (M/L _{ K } = 113 ± 15 M _{⊙}/L _{⊙}), and a mass for the MW plus M31 of 5.15 ± 0.35 × 10^{12} M _{⊙}. The best constant masstolight ratio is M/L _{ K } = 58 ± 3 M _{⊙}/L _{⊙}. The Virgocentric turnaround radius is 7.3 ± 0.3 Mpc. We explain several interesting trends in peculiar motions for various regions now that we can construct the 3D orbital histories.
 Publication:

The Astrophysical Journal
 Pub Date:
 December 2017
 DOI:
 10.3847/15384357/aa9525
 arXiv:
 arXiv:1710.08935
 Bibcode:
 2017ApJ...850..207S
 Keywords:

 cosmological parameters;
 galaxies: distances and redshifts;
 galaxies: kinematics and dynamics;
 largescale structure of universe;
 Local Group;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Astrophysics of Galaxies
 EPrint:
 18 pages, 17 Figures, links to online video, interactive plots and a large table