Pattern Speeds of Spiral Galaxies Using the Tremaine-Weinberg Method

Spiral galaxies displaying molecule-dominated ISMs are potential candidates for pattern speed determination by the Tremaine-Weinberg (TW) method (1984); the molecular gas of such galaxies, as traced by CO emission, is argued to approximately obey the continuity equation on orbital timescales--a key requirement of the method. We continue our work on this application of the Tremaine-Weinberg method with pattern speed determinations of several galaxies using CO emission data cubes from the BIMA SONG survey, wherein the molecular dominance of each of the three galaxies in our sample (NGC 5457, 5033, and 5055) is established using radial profiles of Wong and Blitz (2002).