176 research outputs found
Triple Disruptions in The Galactic Centre: Captured and Ejected Binaries, Rejuvenated Stars, and Correlated Orbits
The disruption of a binary star by a massive black hole (MBH) typically leads
to the capture of one component around the MBH and the ejection of its
companion at a high velocity, possibly producing a hypervelocity star. The high
fraction of observed triples (% for F/G/K stars and % for OB
stars) give rise to the possibility of the disruption of triples by a MBH. Here
we study this scenario, and use direct -body integrations to follow the
orbits of thousands of triples, during and following their disruption by a MBH
(of M, similar to the MBH existing in the Galactic
Centre; SgrA). We find that triple disruption can lead to several outcomes
and we discuss their relative frequency. Beside the ejection/capture of single
stars, similar to the binary disruption case, the outcomes of triple disruption
include the ejection of hypervelocity binaries; capture of binaries around the
MBH; collisions between two or all of the triple components (with low enough
velocities that could lead to their merger); and the capture of two or even
three stars at close orbits around the MBH. The orbits of single stars captured
in a single disruption event are found to be correlated. The eccentricity of
the mutual orbits of captured/ejected binaries is typically excited to higher
values. Stellar evolution of captured/ejected binaries may later result in
their coalescence/strong interaction and the formation of hypervelocity blue
stragglers or merger remnants in orbits around SgrA*. Finally, the capture of
binaries close to the MBH can replenish and increase the binary frequency near
the MBH, which is otherwise very low.Comment: 8 pages, 2 figures, 3 tables, submitted to MNRA
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