Action Dynamics of the Local Supercluster

作者：Shaya Edward J; Tully R Brent; Hoffman Yehuda; Pomarede Daniel

来源：Astrophysical Journal, 2017, 850(2): 207.

DOI：10.3847/1538-4357/aa9525

• cosmological parameters
• galaxies: distances and redshifts
• galaxies: kinematics and dynamics
• large-scale structure of universe
• Local Group

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 larger-scale 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 present-day radial velocities, individually for the Virgo Cluster, M31, and the Milky Way (MW), and via a mass-to-light ratio relationship for other masses. The low median chi-square found indicates that the model fits the present-day velocity flow well, but a slightly high mean chi-square 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 Omega(m) = 0.244 consistent with that H-0, occurs with the following parameters: Omega(orphan) = 0.077 +/- 0.016, M/L-K = 40 +/- 2L(10)(0.15) M-circle dot/L-circle dot (L-10 is the K-band luminosity in units of 10(10) L-circle dot), a Virgo mass of 6.3 +/- 0.8 x 10(14) M-circle dot (M/L-K = 113 +/- 15 M-circle dot/L-circle dot), and a mass for the MW plus M31 of 5.15 +/- 0.35 x 10(12) M-circle dot. The best constant mass-to-light ratio is M/L-K = 58 +/- 3 M-circle dot/L-circle dot. 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.

• 出版日期2017-12-1
• 单位中国地震局