Colors, Luminosities, and Masses of Disk Galaxies

Publisher Website
Google Scholar
Abstract
We explore the known dependence of the slope of the Tully-Fisher (TF) relation on observational wavelength using a large multifrequency galaxy data-base. We confirm that (1) in the infrared the slope of the TF relation is close to the value expected for constant mass-to-light ratio, while in the visible it increases with mass. Equivalently we show that the infrared luminosity is a good tracer of the dynamical mass in galaxies, whereas the fraction of blue light decreases with increasing mass. (2) B - H increases with mass (H luminosity) for galaxies of a given Hubble type and, at fixed H luminosity, it is larger in early morphological types. (3) The present star-formation rate and the H I content per unit mass both decrease with increasing dynamical mass. We argue that the above findings have implications on the mechanism of galaxy formation, suggesting that the efficiency of conversion of the primordial mass into stars in the early phases of protogalaxy collapse increases with the dynamical mass of the system.

This publication has 0 references indexed in Scilit: