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The infall field surrounding a cluster of galaxies produces an artifact in redshift space: a wide-angle, disklike ``ring'' which encircles the ``finger of god'' produced by the cluster's virialized core. The ring artifact tilts on its finger axis if there is transverse motion of the cluster relative to the observer or rotation within the cluster. We propose a new ``signature'' method for determining large scale velocity flows directly from redshift plots via the intercluster correlations in ring tilts such flows would produce. We present several schematic scenarios by way of example.
We also present results of detailed modelling of infall fields with transverse motion. We find that the shape of the ring artifact shows little dependence on the particular model used. We show that the standard simple model, spherical accretion onto a point mass, can be expressed in a convenient form with only three parameters: the size of the ring, the length of the finger, and the flatness parameter \Omega_0. Finally, we present preliminary results for redshift-space artifacts produced by rotational flows.
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