Special TAPIR Seminar

In person: 370 Cahill. To Join via Zoom: 851 0756 7442

ABSTRACT: Black hole binaries with extreme mass ratios will be critical targets for the forthcoming Laser Interferometer Space Antenna (LISA) mission. The extreme-mass-ratio limit also provides useful tools for studying the dynamics of compact binary systems and the gravitational waves they emit. Using an eccentric Ori–Thorne procedure, we build worldlines that describe the full inspiral and plunge of a small body on an initially eccentric orbit of a Kerr black hole. We then calculate the gravitational waves associated with these trajectories with a code that solves the Teukolsky equation in the time domain. The ringdown from such a waveform consists of a spectrum of Kerr quasinormal modes (QNMs), followed by a power-law tail.
In this work, we examine the impact of orbital eccentricity and its associated phase parameter, the radial anomaly angle, on the excitation of QNMs and power-law tails. For some anomaly angles, the relative excitations of QNMs are essentially indistinguishable from those excited in quasi-circular coalescences. Consistent with other recent studies, we find that eccentricity tends to amplify the late-time power-law tail, though the amount of this amplification varies significantly with orbital anomaly. We thus find that eccentricity can have a distinct impact on the late-time coalescence waveform, but the interplay of eccentricity and orbital anomaly complicates this impact.