THE I-BAND TULLY-FISHER RELATION FOR CLUSTER GALAXIES - A TEMPLATE RELATION, ITS SCATTER AND BIAS CORRECTIONS

Infrared I band photometry and velocity widths for galaxies in 24 clus ters, with radial velocities between 1,000 and 10,000 km s(-1), are us ed to construct a template Tully-Fisher (TF) relation. The sources of scatter in the TF diagram are analyzed in detail; it is shown that the common practice of referring to a single figure of TF scatter is inco rrect and can lead to erroneous bias corrections, Biases resulting fro m sample incompleteness, catalog inaccuracies, cluster size and other sources, as well as dependences of TF parameters on morphological type and local environment, are discussed and appropriate corrections are obtained. A template TF relation is constructed by combining the data from the 24 clusters, and kinematic cluster offsets from a putative re ference frame which well approximates null velocity with respect to th e cosmic microwave background, are obtained. (C) 1997 American Astrono mical Society.