2000/03/01 by Stacy McGaugh, Jim Schombert, Greg Bothun +1
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/312628
published as Astrophys.J. 533 (2000) L99-L102 · 10 pages including 1 color figure. Accepted for publication in ApJ Letters
arxiv created 2000/03/01 · arxiv updated 2009/12/01
We explore the Tully-Fisher relation over five decades in stellar mass in galaxies with circular velocities ranging over 30 < Vc < 300 km/s. We find a clear break in the optical Tully-Fisher relation: field galaxies with Vc < 90 km/s fall below the relation defined by brighter galaxies. These faint galaxies are however very gas rich; adding in the gas mass and plotting baryonic disk mass Md = M* + Mg in place of luminosity restores a single linear relation. The Tully-Fisher relation thus appears fundamentally to be a relation between rotation velocity and total baryonic mass of the form Md = A Vc4.