In this paper we derive a Tully Fisher relation from measured I band
photometry and Hα rotation curves of a large survey of southern sky
spiral galaxies, obtained in Persic \& Salucci (1995) by deprojecting and
folding the raw Hα data of Mathewson, Ford \& Buchhorn (1992). We
calibrate the relation by combining several of the largest clusters in the
survey, using an iterative maximum likelihood procedure to account for
observational selection effects and Malmquist bias. We also incorporate a
simple model for the line of sight depth of each cluster. Our results indicate
a Tully Fisher relation of intrinsic dispersion ∼0.3 mag, corresponding to
a distance error dispersion of 13%. Application of this relation to mapping
the large scale velocity field is underway.Comment: Plain TeX Version 3.0, 4 pages, to appear in `Astrophysical Letters
and Communications' - proceedings of the international workshop on
observational cosmology: `From Galaxies to Galaxy Systems', Sesto, July 199