Gravitational radiation from point-masses in unbound orbits - Newtonian results

Gravitational radiation from a system of two point-masses in unbound orbits (orbital eccentricity of at least unity) is calculated to Newtonian order in the multipole formalism. Waveforms of the multipole amplitudes are presented for bound and unbound orbits. The energy emitted in gravitational waves from an unbound encounter is given by an enhancement factor times a function of the other orbital parameters (similar to the results of Peters and Mathews (1963) for bound systems). Energy spectra of the gravitational radiation emitted are also presented.