Polarization amplitudes of a hierarchical 2+2 system

Abstract

One of the sources of space-based gravitational wave (GW) astronomy would be compact objects such as white dwarfs, which are the most common endpoint in a typical star’s lifetime. In this work, we investigated the GW emission of two double white dwarf systems in a 2+2 hierarchical structure which was found to be able to synchronize its binary frequencies with the assistance of interbinary mass transfer. We looked for the possible synchronization imprints in its GW signal. We found beating patterns in the time evolution of the components of the amplitude of its GW polarization. We also found that the orbital frequencies of the binaries would merge in the frequency domain. Spectrograms of the signal also showed that the merging happened later after the synchrony capture.