Yosef Zlochower

Maximum gravitational recoil

Recent calculations of gravitational radiation recoil generated during black-hole binary mergers have reopened the possibility that a merged binary can be ejected even from the nucleus of a massive host galaxy. Here we report the first systematic study of gravitational recoil of equal-mass binaries with equal, but counteraligned, spins parallel to the orbital plane. Such an orientation of the spins is expected to maximize the recoil. We find that recoil velocity (which is perpendicular to the orbital plane) varies sinusoidally with the angle that the initial spin directions make with the initial linear momenta of each hole and scales up to a maximum of approximately 4000 km s-1 for maximally rotating holes. Our results show that the amplitude of the recoil velocity can depend sensitively on spin orientations of the black holes prior to merger.

Large Merger Recoils and Spin Flips from Generic Black Hole Binaries

We report the first results from the evolution of generic black hole binaries, i.e., binaries containing unequal-mass black holes with misaligned spins. Our configuration, which has a mass ratio of 2?:?1, consists of an initially nonspinning hole orbiting a larger, rapidly spinning hole (specific spin a/m = 0.885), with the spin direction oriented -45? with respect to the orbital plane. We track the inspiral and merger for ~2 orbits and find that the remnant receives a substantial kick of 454 km s-1, more than twice as large as the maximum kick from nonspinning binaries. The remnant spin direction is flipped by 103? with respect to the initial spin direction of the larger hole. We performed a second run with antialigned spins, a/m = ?0.5 lying in the orbital plane that produces a kick of ~1830 km s-1 off the orbital plane. This value scales to nearly 4000 km s-1 for maximally spinning holes. Such a large recoil velocity opens up the possibility that a merged binary can be ejected even from the nucleus of a massive host galaxy.

Spinning-black-hole binaries : The orbital hang-up

We present the first fully-nonlinear numerical study of the dynamics of highly-spinning-black-hole binaries. We evolve binaries from quasicircular orbits (as inferred from post-Newtonian theory), and find that the last stages of the orbital motion of black-hole binaries are profoundly affected by their individual spins. In order to cleanly display its effects, we consider two equal-mass holes with individual spin parameters

CIRCUMBINARY MAGNETOHYDRODYNAMIC ACCRETION INTO INSPIRALING BINARY BLACK HOLES

S/{m}^{2}=0.757

Testing gravitational-wave searches with numerical relativity waveforms: results from the first Numerical INJection Analysis (NINJA) project

, both aligned and antialigned with the orbital angular momentum (and compare with the spinless case), and with an initial orbital period of

Hangup Kicks: Still Larger Recoils by Partial Spin/Orbit Alignment of Black-Hole Binaries

125M

Accurate black hole evolutions by fourth-order numerical relativity

. We find that the aligned case completes three orbits and merges significantly after the antialigned case, which completes less than one orbit. The total energy radiated for the former case is

Error-analysis and comparison to analytical models of numerical waveforms produced by the NRAR Collaboration

\ensuremath{\approx}7%

Remnant masses, spins and recoils from the merger of generic black hole binaries

while for the latter it is only

Spin Flips and Precession in Black-Hole-Binary Mergers

\ensuremath{\approx}2%