Mergers of black hole binaries driven by misaligned circumbinary discs. (arXiv:2311.10160v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Martin_R/0/1/0/all/0/1">Rebecca G. Martin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lepp_S/0/1/0/all/0/1">Stephen Lepp</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_B/0/1/0/all/0/1">Bing Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nixon_C/0/1/0/all/0/1">C. J. Nixon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Childs_A/0/1/0/all/0/1">Anna C. Childs</a>
With hydrodynamical simulations we examine the evolution of a highly
misaligned circumbinary disc around a black hole binary including the effects
of general relativity. We show that a disc mass of just a few percent of the
binary mass can significantly increase the binary eccentricity through
von-Zeipel–Kozai-Lidov (ZKL) like oscillations provided that the disc lifetime
is longer than the ZKL oscillation timescale. The disc begins as a relatively
narrow ring of material far from the binary and spreads radially. When the
binary becomes highly eccentric, disc breaking forms an inner disc ring that
quickly aligns to polar. The polar ring drives fast retrograde apsidal
precession of the binary that weakens the ZKL effect. This allows the binary
eccentricity to remain at a high level and may significantly shorten the black
hole merger time. The mechanism requires the initial disc inclination relative
to the binary to be closer to retrograde than to prograde.
With hydrodynamical simulations we examine the evolution of a highly
misaligned circumbinary disc around a black hole binary including the effects
of general relativity. We show that a disc mass of just a few percent of the
binary mass can significantly increase the binary eccentricity through
von-Zeipel–Kozai-Lidov (ZKL) like oscillations provided that the disc lifetime
is longer than the ZKL oscillation timescale. The disc begins as a relatively
narrow ring of material far from the binary and spreads radially. When the
binary becomes highly eccentric, disc breaking forms an inner disc ring that
quickly aligns to polar. The polar ring drives fast retrograde apsidal
precession of the binary that weakens the ZKL effect. This allows the binary
eccentricity to remain at a high level and may significantly shorten the black
hole merger time. The mechanism requires the initial disc inclination relative
to the binary to be closer to retrograde than to prograde.
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