Spherical Infall Model Research Articles

Velocity fields around rich clusters of galaxies

view Abstract Citations (66) References (37) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Velocity Fields around Rich Clusters of Galaxies Villumsen, J. V. ; Davis, M. Abstract The authors study the nature of the velocity field around large clusters in Ω = 1 cosmological N-body simulations that have initial conditions which produce large-scale structure reasonably consistent with observations. The purpose is to test the accuracy of the spherical infall models commonly used to measure the mass of the Virgo supercluster and to characterize the nature of the deviations from simple spherical infall. The use of a spherical model for the Virgocentric flow as a measure of Ω is shown to be subject to large systematic and random errors. A much better test is to use a local criterion, noting that local peculiar velocity tracks the direction and amplitude of the local peculiar gravitational force extremely well. Publication: The Astrophysical Journal Pub Date: September 1986 DOI: 10.1086/164521 Bibcode: 1986ApJ...308..499V Keywords: Computational Astrophysics; Galactic Clusters; Many Body Problem; Velocity Distribution; Boundary Value Problems; Cosmology; Gravitational Effects; Mass Distribution; Virgo Galactic Cluster; Astrophysics; COSMOLOGY; GALAXIES: CLUSTERING; NUMERICAL METHODS full text sources ADS | data products SIMBAD (2)

On the application of a spherical infall model to the local supercluster

view Abstract Citations (17) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Application of a Spherical Infall Model to the Local Supercluster Lee, H. ; Hoffman, Y. ; Ftaclas, C. Abstract The application of a spherical, nonlinear infall model to the Local Supercluster (LSC), and in particular its reliability as a cosmological probe of Omega(0), are studied by means of N-body simulations. An N-body model of a flat universe with an initial Poisson distribution has been analyzed by identifying objects similar to the LSC, and calculating the apparent values of Omega(0), Omega(st), by the standard (nonlinear spherical infall) model. The distribution of the values of Omega(st) ranges from 0.65 to 1.05 with a mean of 0.92, compared to the Omega(0) = 1.0 of the simulation. The value Omega(st) is correlated with the structure of the velocity field and the more spherical superclusters are found to underestimate Omega(0) by 20 percent-40 percent. The derived values of Omega(0) are in the same range of values predicted by the 1985 quasi-linear model of Hoffman. An implication of the present study is that the standard cosmological scenario of a flat universe is incompatible with the observed LSC. Publication: The Astrophysical Journal Pub Date: May 1986 DOI: 10.1086/184660 Bibcode: 1986ApJ...304L..11L Keywords: Astronomical Models; Celestial Mechanics; Galactic Clusters; Galactic Evolution; Many Body Problem; Algorithms; Cosmology; Local Group (Astronomy); Spatial Distribution; Velocity Distribution; Astrophysics; COSMOLOGY; GALAXIES: CLUSTERING; GALAXIES: FORMATION full text sources ADS | data products SIMBAD (1)