Speaker
Description
We quantify for the first time the gravitational wave (GW) phase shift appearing in the waveform
of eccentric binary black hole (BBH) mergers formed dynamically in three-body systems. For this,
we have developed a novel numerical method where we construct a reference binary, by evolving the
post-Newtonian (PN ) evolution equations backwards from a point near merger without the inclusion
of the third object, that can be compared to the real binary that evolves under the influence from
the third BH. From this we quantify how the interplay between dynamical tides, PN -effects, and the
time-dependent Doppler shift of the eccentric GW source results in unique observable GW phase shifts
that can be mapped to the gravitational dynamics taking place at formation. We further find a new
analytical expression for the GW phase shift, which surprisingly has a universal functional form that
only depends on the time-evolving BBH eccentricity. The normalization scales with the BH masses
and initial separation, which can be linked to the underlying astrophysical environment. GW phase
shifts from a chaotic 3-body BH scattering taking place in a cluster, and from a BBH inspiraling in
a disk migration trap near a super-massive BH, are also shown for illustration. When current and
future GW detectors start to observe eccentric GW sources with high enough signal-to-noise-ratio, we
propose this to be among the only ways of directly probing the dynamical origin of individual BBH
mergers using GWs alone.
| Affliation | Niels Bohr Institute |
|---|---|
| Current Position | PhD Student |
