Precession resonances in hierarchical triple systems

Abstract

We describe a new kind of resonance occuring in relativistic three-body hierarchical systems: the precession resonance, occuring when the relativistic precession timescale of a binary equals the period of a distant perturber. We find that, contrary to what most previous studies assume, it can lead to an exponential increase of eccentricity of the binary even when relativistic precession dominates the quadrupolar perturbation. The resonance may happen in the observation band of LISA or change the eccentricity distribution of triples. We discuss the physics of the resonance, showing that it mainly depends on three parameters.