  Core-satellite structures are known to exhibit magnetic modes at optical
frequencies and their characterization is important for the development of
metamaterials and metafluids. We develop a finite-difference time-domain
electrodynamics simulation and multipolar analysis approach and apply it to
identify the electric and magnetic multipolar nature of modes excited in
core-satellite structures composed of silver nanoparticles decorated on
dielectric spheres. In addition to excitation with linearly polarized scalar
beams, we investigate the scattering and multipolar properties induced by
cylindrical vector beams. In contrast to linearly polarized beams, the nature
of the polarization state in these beams (radial, azimuthal, or "shear") can
selectively excite, enhance, and rotate a family of multipolar modes.
Displacement currents induced in the nanoparticle gaps are investigated to
better understand the nature of these excitations. We show that the efficiency
of driving these modes depends on nanoparticle density and placement. We
propose that selective magnetic and electric excitations can be codified as
"selection rules" associated with the symmetries of the beams and particles.
