Physical Sciences and Mathematics Commons^™

A New Formula Describing The Scaffold Structure Of Spiral Galaxies, Harry I. Ringermacher, Lawrence R. Mead

Faculty Publications

We describe a new formula capable of quantitatively characterizing the Hubble sequence of spiral galaxies including grand design and barred spirals. Special shapes such as ring galaxies with inward and outward arms are also described by the analytic continuation of the same formula. The formula is r() = A/log [B tan (/2N)]. This function intrinsically generates a bar in a continuous, fixed relationship relative to an arm of arbitrary winding sweep. A is simply a scale parameter while B, together with N, determines the spiral pitch. Roughly, greater N results in tighter winding. Greater B results in greater arm sweep …