Session 82 - Globular Clusters.
Display session, Wednesday, January 17
North Banquet Hall, Convention Center

## [82.15] Tidal Effects on Spherical Stellar Systems.

L. Hernquist (UCSC), K. V. Johnston (UCSC)

Many external influences on spherical stellar systems can be well-represented by a potential given by a sum over a small number of terms of the form \Phi_lm=A_lm(t) r^2 Y_lm(\theta,\phi), where (r,\theta,\phi) are conventional spherical coordinates centered on the perturbed system, Y_lm is a spherical harmonic and A_lm is the time dependent amplitude, calculated from the orbit of the system and the nature of the perturbing potential. In this project, we investigate the response of the stellar system to a single \Phi_lm, using a combination of linear theory and N-body simulations. The power in the formalism lies in its simplicity, which aims to isolate physical causes for effects seen in full N-body simulations of general interactions, and hence form a bridge between linear and fully non-linear studies. The method is applicable to a wide variety of astrophysical problems, such as the shocking of globular clusters by the disk, bulge or massive black holes, the disruption of dwarf spheroidal galaxies and encounters between elliptical galaxies or haloes. Issues that can be addressed include tidal shocking in the impulsive and adiabatic regimes, tidal disruption and tidal limitation.