The $V_{\rm circ}$-$\sigma_{\rm c}$ relation in high and low surface brightness galaxies

Abstract

We investigate the relation between the asymptotic circular velocity, $V_{\rm circ}$, and the central stellar velocity dispersion, $\sigma_{\rm c}$, in galaxies. We consider a new sample of high surface brightness spiral galaxies (HSB), low surface brightness spiral galaxies (LSB), and elliptical galaxies with HI-based $V_{\rm circ}$ measurements. We find that: 1) elliptical galaxies with HI measurements fit well within the relation; 2) a linear law can reproduce the data as well as a power law (used in previous works) even for galaxies with $\sigma_{\rm c} \lt 70$ km/s; 3) LSB galaxies, considered for the first time with this respect, seem to behave differently, showing either larger $V_{\rm circ}$ values or smaller $\sigma_{\rm c}$ values.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html