Galaxy Masses: Disks and Their Halos

Abstract

I review what we currently do and do not know about the masses of disk galaxies and their dark matter halos. The prognosis for disks is good: the asymptotic rotation velocity provides a good indicator of total disk mass. The prognosis for halos is bad: cuspy halos provide a poor description of the data, and the total mass of individual dark matter halos remains ill-constrained.

6 pages. Invited review for the ESO workshop The Mass of Galaxies at Low and High Redshift, ed. R. Bender & A. Renzini. (Text unchanged. Info in this comment line got scrambled in original submission: this bibliographic information is the only change.)