The V_c-sigma_c relation in high and low surface brightness galaxies
  We investigate the relation between the asymptotic circular velocity, V_c, and the central stellar velocity dispersion, sigma_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_c 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_c < 70 km/s; 3) LSB galaxies, considered for the first time with this respect, seem to behave differently, showing either larger V_c values or smaller sigma_c values. 
A. Pizzella (1), E. Dalla Bonta` (1), E.M. Corsini (1), L. Coccato   (1), M. Sarzi (2) and F. Bertola (1) ((1) Dipartimento ...