170 research outputs found

    Triple Disruptions in The Galactic Centre: Captured and Ejected Binaries, Rejuvenated Stars, and Correlated Orbits

    Full text link
    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 (∼10\sim10% for F/G/K stars and ∼50\sim50% for OB stars) give rise to the possibility of the disruption of triples by a MBH. Here we study this scenario, and use direct NN-body integrations to follow the orbits of thousands of triples, during and following their disruption by a MBH (of 4×1064\times10^6 M⊙_\odot, 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
    • …
    corecore