Galaxy flows within 8,000 km/s from Numerical Action methods

Abstract

The trajectories since z=4 of systems of galaxies (`halos') with cz < 8,000 km/s are found through Numerical Action reconstructions. A set of 9,719 halos from a 2MASS group catalog and Cosmicflows-3 catalogs are given attention. Present distances are adjusted to minimize departures from observed redshifts. For those with the most precisely determined distances, compromises are made between distance and redshift agreement. $H_0$ is varied from 69 to 77 km s${}^{-1}$ Mpc${}^{-1}$ with ${\Omega }_m$ set by the baryon acoustic oscillation constraint from the Planck Satellite. A best fitting amplitude of the mass-to-light relation is found. A uniform density associated with the interhalo medium accounts for the matter not in halos. The solution paths provide the histories of the formation of the nearby large structures and depict how the voids emptied. Assuming no local over/underdensity, the best model has $H_0=73$ km s${}^{-1}$ Mpc${}^{-1}$ with nearly the same density arising from interhalo matter (IHM) as from halos. We examine local over/underdensities by varying the IHM density and find a valley of best fit models along $H_0=73.0(1+0.165\delta )$ km s${}^{-1}$ Mpc${}^{-1}$. Friedmann models with distinct densities internal and external to the study region give a similar relationship. The fraction of matter in the IHM seen in n-body simulations roughly matches that in our $H_0=72$ scenario. Videos have been created to visualize the complexities of formation of large-scale structures. Standard n-body calculations starting from the first time-steps as tests of the NAM solutions, and continue until cosmic scale factor $a=2$ provide glimpses into the future.

29 pages, 28 figures, 4 links to sketchfab.com, and 4 links to vimeo.com videos

References in corpus (23)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
• Cosmic Distances Calibrated to 1% Precision with Gaia EDR3 Parallaxes and Hubble Space Telescope Photometry of 75 Milky Way Cepheids Confirm Tension with LambdaCDM
• The Laniakea supercluster of galaxies
• Cosmological parameters from the comparison of peculiar velocities with predictions from the 2M++ density field
• The M31 Velocity Vector. II. Radial Orbit Towards the Milky Way and Implied Local Group Mass
• Galaxy Groups within 3500 km s${}^{-1}$
• The 6dF Galaxy Survey: Peculiar Velocity Field and Cosmography
• The Local Perspective on the Hubble Tension: Local Structure Does Not Impact Measurement of the Hubble Constant
• Galaxy Groups: A 2MASS Catalog
• Action Dynamics of the Local Supercluster
• Cosmicflows 4: The Calibration of Optical and Infrared Tully-Fisher Relations
• Galaxy Groups
• The Extragalactic Distance Database: The Color-Magnitude Diagrams and Tip of the Red Giant Branch Distances Catalog
• The peculiar velocity field up to $z\sim 0.05$ by forward-modeling Cosmicflows-3 data
• The Dipole Repeller
• Structures in the Great Attractor Region
• The Calibration of the WISE W1 and W2 Tully-Fisher Relation
• The Cosmic V-Web
• Cosmicflows-3: The South Pole Wall
• Local Hole revisited: evidence for bulk motions and self-consistent outflow
• From Cosmicflows distance moduli to unbiased distances and peculiar velocities