The Tully-Fisher (TF) relation is an empirically establish correlation between the luminosity of a spiral galaxy and its rotational velocity (Tully-Fisher, 1977). We used the Tully-Fisher relation to probe the dark matter (DM) distribution in the optical regions of spiral galaxies. We investigated a sample of rotation curves that includes 957 galaxies. We applied a new technique that takes advantage of the full knowledge of the galaxy rotation curves.
