Mass-to-Light ratio, Initial Mass Function and chemical evolution in disc galaxies
Abstract
Cosmological simulations of disc galaxy formation, when compared to the observed Tully-Fisher relation, suggest a low Mass-to-Light (M/L) ratio for the stellar component in spirals. We show that a number of "bottom-light" Initial Mass Functions (IMFs) suggested independently in literature, do imply M/L ratios as low as required, at least for late type spirals (Sbc/Sc). However the typical M/L ratio, and correspondingly the zero-point of the Tully-Fisher relation, is expected to vary considerably with Hubble type. Bottom-light IMFs tend to have a metal production in excess of what is tipically estimated for spiral galaxies. Suitable tuning of the IMF slope and mass limits, post-supernova fallback of metals onto black holes or metal outflows must then be invoked, to reproduce the observed chemical properties of disc galaxies.
Cite
@article{arxiv.astro-ph/0402427,
title = {Mass-to-Light ratio, Initial Mass Function and chemical evolution in disc galaxies},
author = {L. Portinari and J. Sommer-Larsen and R. Tantalo},
journal= {arXiv preprint arXiv:astro-ph/0402427},
year = {2007}
}
Comments
4 pages, 6 colour figures. To appear on PASA (refereed proceedings of Galactic ChemoDynamics V, B.K. Gibson and D. Kawata eds.)