Peculiar Velocity Dipoles of Field Galaxies

The Density and Peculiar Velocity Elds of Nearby Galaxies

We review the quantitative science that can be and has been done with redshift and peculiar velocity surveys of galaxies in the nearby universe. After a brief background setting the cosmological context for this work, the rst part of this review focuses on redshift surveys. The practical issues of how redshift surveys are carried out, and how one turns a distribution of galaxies into a smoothed...

Peculiar Galaxies

Hierarchical Object Formation in the Peculiar Velocity Field

Using the initial peculiar-velocity field, we analytically study the hierarchical formation of gravitationally bound objects. The field is smoothed over a scale that corresponds to the mass of a given class of objects. Through the Zel’dovich approximation, the smoothed field determines how the objects cluster together to form a new class of more massive objects. The standard cosmological parame...

A robust method for fitting peculiar velocity field models

We present a new method for fitting peculiar velocity models to complete flux limited magnitude-redshifts catalogues, using the luminosity function of the sources as a distance indicator. The method is characterised by its robustness. In particular, no assumptions are made concerning the spatial distribution of sources and their luminosity function. Moreover, selection effects in redshift are a...

The peculiar velocity field in a quintessence model

We investigate the evolution of matter density perturbations and some properties of the peculiar velocity field for a special class of exponential potentials in a scalar field model for quintessence, for which a general exact solution is known. The data from the 2-degree Field Galaxy Redshift Survey (2dFGRS) suggest a value of the today pressureless matter density ΩM0 = 0.18±0.05.