Gravitational-wave-induced oscillations of a viscoelastic sphere

Abstract

Siegel and Roth [Mon. Not. R. Astron. Soc. 408, 1742 (2010)] introduced an excitation model in which they treat a vibrating solar-like star due to external gravitational waves (GWs) as a gigantic spherical resonant mass detector. In this study, we complete their work by providing an expression for the damping term η_N that can be numerically evaluated. This allows us to numerically compute the Q-factor of the quadrupolar spheroidal modes and study its properties. We then provide an extension to the solid sphere model by presenting a formulation for a sphere composed of two layers of different material properties called the dual sphere. We are mainly interested on the Q-factors of the normal modes and examine how the parameters of the solid and dual sphere models affect them.