Compact stars within a soft symmetry energy quark-meson-coupling model

We investigate compact star properties within the quark-meson-coupling model with a soft symmetry energy density dependence at large densities. In particular, the hyperon content and the mass/radius curves for the families of stars obtained within the model are discussed. The hyperon-meson couplings are chosen according to experimental values of the hyperon nuclear matter potentials, and possible uncertainties are considered. It is shown that a softer symmetry energy gives rise to stars with less hyperons, smaller radii, and larger masses. Hyperon-meson couplings may also have a strong effect on the mass of a star.