Dynamics of pairwise motions

Citation
R. Juszkiewicz et al., Dynamics of pairwise motions, ASTROPHYS J, 518(1), 1999, pp. L25-L28
Citations number
25
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
518
Issue
1
Year of publication
1999
Part
2
Pages
L25 - L28
Database
ISI
SICI code
0004-637X(19990610)518:1<L25:DOPM>2.0.ZU;2-U
Abstract
We propose a simple closed-form expression relating v(12)(r)-the mean relat ive velocity of pairs of galaxies at fixed separation r-to the two-point co rrelation function of mass density fluctuations, xi(r). Our Ansatz is an in terpolation between the perturbative and stable clustering expressions for v(12). We compare our analytic model for v(12)(r) with N-body simulations a nd find excellent agreement in the entire dynamical range probed by the sim ulations (0.1 less than or similar to xi less than or similar to 1000). Our results can be used to estimate the cosmological density parameter, Omega, directly from redshift-distance surveys.