The importance of precession in modelling the direction of the final spin from a black-hole merger

Abstract

The prediction of the spin of the black hole resulting from the merger of a generic black-hole binary system is of great importance to study the cosmological evolution of supermassive black holes. Several attempts have been recently made to model the spin via simple expressions exploiting the results of numerical-relativity simulations. Here, I first review the derivation of a formula, proposed in Barausse & Rezzolla, Apj 704 L40, which accurately predicts the final spin magnitude and direction when applied to binaries with separations of hundred or thousands of gravitational radii. This makes my formula particularly suitable for cosmological merger-trees and N-body simulations, which provide the spins and angular momentum of the two black holes when their separation is of thousands of gravitational radii. More importantly, I investigate the physical reason behind the good agreement between my formula and numerical relativity simulations, and nail it down to the fact that my formula takes into account the post-Newtonian precession of the spins and angular momentum in a consistent manner.

6 pages, 2 figures. Panel added to fig 2, discussion extended to comply with referee's comments. Version accepted for publication as proceeding of the 8th Amaldi International Conference on Gravitational Waves, NYC, 21-26 June 2009

References in corpus (13)

• Large Merger Recoils and Spin Flips From Generic Black-Hole Binaries
• High-accuracy waveforms for binary black hole inspiral, merger, and ringdown
• On the final spin from the coalescence of two black holes
• Estimating the final spin of a binary black hole coalescence
• Spin Flips and Precession in Black-Hole-Binary Mergers
• The final mass and spin of black hole mergers
• Dual black holes in merger remnants. II: spin evolution and gravitational recoil
• The final spin from the coalescence of aligned-spin black-hole binaries
• Binary black hole mergers: large kicks for generic spin orientations
• Modeling gravitational recoil from precessing highly-spinning unequal-mass black-hole binaries
• Binary black hole merger: symmetry and the spin expansion
• The spin expansion for binary black hole merger: new predictions and future directions
• Can binary mergers produce maximally spinning black holes?

Cited by in corpus (5)

• The final spin from binary black holes in quasi-circular orbits
• Spinning compact binary inspiral: Independent variables and dynamically preserved spin configurations
• Exploring the nature of black hole and gravity with an imminent merging binary of supermassive black holes
• Spinning compact binary inspiral II: Conservative angular dynamics
• The typical mass ratio and typical final spin in supermassive black hole mergers