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Next: The Large Velocity Approach to H Up: Do we know the velocity field well Previous: Introduction

The Velocity field

The Virgocentric flow field is now a classic (Peebles 1976, Schechter 1980). In its simplest form there is one parameter, the local value of the infall velocity. Noteable estimates include:

New estimates within this range are by Staveley-Smith (this meeting) and Tonry (this meeting).

Reaching out a little further, the bilinear infall model adds a second mass concentration to the kinematic description. Han & Mould (1990,1992) have applied this formulation to two physical situations,

Virgo plus the Great Attractor,

Perseus-Pisces and the Great Attractor.

These formulations can be compared with simpler models involving bulk flows, such as,

the early bulk flow model of the Seven Samurai (Dressler et al 1987)

the 100 Mpc bulk flow of Mathewson and Ford (1994).

Taking the rms over all these models, Han & Mould (1992) find

Non parametric models are in principle capable of a better description of the velocity field and have been discussed by Tully at this meeting.



next up previous
Next: The Large Velocity Approach to H Up: Do we know the velocity field well Previous: Introduction



Heron Island Conference
Tue Aug 15 22:04:57 EST 1995