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arXiv · 1307.0010

Tearing up the disc: misaligned accretion on to a binary

Chris Nixon·Andrew King·Daniel Price
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Abstract

In a recent paper we have shown that the evolution of a misaligned disc around a spinning black hole can result in tearing the disc into many distinct planes. Tearing discs with random orientations produce direct dynamical accretion on to the hole in approximately 70% of all cases. Here we examine the evolution of a misaligned disc around a binary system. We show that these discs are susceptible to tearing for almost all inclinations. We also show that tearing of the disc can result in a significant acceleration of the disc evolution and subsequent accretion on to the binary - by factors up to 10,000 times that of a coplanar prograde disc with otherwise identical parameters. This provides a promising mechanism for driving mergers of supermassive black hole (SMBH) binaries on timescales much shorter than a Hubble time. Disc tearing also suggests new observational signatures of accreting SMBH binaries, and other systems such as protostellar binaries.

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Chris Nixon, Andrew King, Daniel Price. 2013-06-28. Tearing up the disc: misaligned accretion on to a binary. https://doi.org/10.1093/mnras/stt1136

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