On the Formation of an Eccentric Nuclear Disk following the Gravitational Recoil Kick of a Supermassive Black Hole

TL;DR

This paper demonstrates that gravitational recoil kicks from black hole mergers can directly lead to the formation of eccentric nuclear stellar disks with distinctive orbital patterns.

Contribution

It introduces a novel mechanism showing how black hole recoil can produce eccentric stellar disks with specific orbital alignments and eccentricity distributions.

Findings

Eccentric nuclear disks can form immediately after black hole recoil events.

The resulting disks have a unique 'tick-mark' eccentricity distribution.

A spiral pattern appears in the mean anomaly of the stars.

Abstract

The anisotropic emission of gravitational waves during the merger of two supermassive black holes can result in a recoil kick of the merged remnant. We show here that eccentric nuclear disks - stellar disks of eccentric, apse-aligned orbits - can directly form as a result. An initially circular disk of stars will align orthogonal to the black hole kick direction with a distinctive 'tick-mark' eccentricity distribution and a spiral pattern in mean anomaly.