Small-N collisional dynamics: pushing into the realm of not-so-small N

Leigh, Nathan W. C.; Geller, Aaron M.

doi:10.1111/j.1365-2966.2012.21689.x

Cited by 51 publications

(69 citation statements)

References 39 publications

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“…In general, we expect damping to facilitate collisions, and increase the frequency of collisions relative to our calculations. Similarly, in the case of stable or long-lived triples (which we neglect in our simulations), the presence of a distant third companion could reduce the timescale for a subsequent encounter, increase the collision probability during individual encounters (Leigh & Geller 2012) or even drive the inner binary to shorter periods or even merge due to KozaiLidov oscillations (Perets & Fabrycky 2009). Hence, our calculated collision rates should increase if these damping sources and stable triples are included in our analysis.…”

Section: Methodsmentioning

confidence: 99%

MOCCA code for star cluster simulations – IV. A new scenario for intermediate mass black hole formation in globular clusters

Giersz

Leigh

Hypki

et al. 2015

Mon. Not. R. Astron. Soc.

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We discuss a new scenario for the formation of intermediate mass black holes in dense star clusters. In this scenario, intermediate mass black holes are formed as a result of dynamical interactions of hard binaries containing a stellar mass black hole, with other stars and binaries. We discuss the necessary conditions to initiate the process of intermediate mass black hole formation and the influence of an intermediate mass black hole on the host global globular cluster properties. We discuss two scenarios for intermediate mass black hole formation. The SLOW and FAST scenarios. They occur later or earlier in the cluster evolution and require smaller or extremely large central densities, respectively. In our simulations, the formation of intermediate mass black holes is highly stochastic. In general, higher formation probabilities follow from larger cluster concentrations (i.e. central densities). We further discuss possible observational signatures of the presence of intermediate mass black holes in globular clusters that follow from our simulations. These include the spatial and kinematic structure of the host cluster, possible radio, X-ray and gravitational wave emissions due to dynamical collisions or mass-transfer and the creation of hypervelocity main sequence escapers during strong dynamical interactions between binaries and an intermediate mass black hole. All simulations discussed in this paper were performed with the MOCCA Monte Carlo code. MOCCA accurately follows most of the important physical processes that occur during the dynamical evolution of star clusters but, as with other dynamical codes, it approximates the dissipative processes connected with stellar collisions and binary mergers.

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Section: Methodsmentioning

confidence: 99%

MOCCA code for star cluster simulations – IV. A new scenario for intermediate mass black hole formation in globular clusters

Giersz

Leigh

Hypki

et al. 2015

Mon. Not. R. Astron. Soc.

Self Cite

256

290

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“…It is also worth noting here that for the binary and triple fractions observed in these particular open clusters, encounters involving triples may be the most frequent type of dynamical encounter [57]. Therefore, though I've focused in Section 2 on the impact of binary stars on star cluster evolution, and indeed (primordial) triples are typically excluded from star cluster models (due to computational limitations), triples may be very important contributors to the dynamical evolution of star clusters, and perhaps also the production of exotic stars that are thought to result from dynamical encounters.…”

Section: Dynamical Processing Of Stars and Planets Through Star Clustersmentioning

confidence: 91%

Dynamical Processing of Stars and Planets Through Star Clusters

Geller¹

2016

Proceedings of Frank N. Bash Symposium 2015 — PoS(BASH2015)

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Most stars are born in clustered environments that are far denser than the Solar Neighborhood.Yet, star clusters can be hostile locations, where close stellar encounters can be frequent and can have violent consequences, including direct stellar collisions. Such encounters can dramatically alter stellar and planetary systems, and can produce exotic stars that define new pathways in stellar evolution. Understanding how, and to what extent, such "dynamically processing" occurs in star clusters may be critical for our understanding of the architectures of today's observed stellar and planetary systems, as well as the origins of X-ray sources, blue stragglers, sub-subgiants, and other stellar exotica. In this contribution, I discuss the impacts of living in a star cluster on its inhabitants, through a review of observational and theoretical efforts to study these complex systems. Throughout, I assert that binary stars are intimately linked to both the dynamical evolution of star clusters and the effects that stellar encounters within these environments have on their stellar and planetary populations. I conclude that in order to properly interpret our present and future observations of stars and planets, both in star clusters and the field, and particularly if we attempt to use these observations to inform star and planet formation theory, we must first account for the imprint left by stellar encounters within a clustered birth environment.

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“…In this section, we introduce our formalism for constructing schematic diagrams of the general three-body problem, adapted from Leigh & Geller (2012) and Leigh et al (2016). We further present the numerical scattering experiments used to study the time evolution of the chaotic three-body problem, from which we construct an illustrative example of our schematic diagram formalism.…”

Section: Methodsmentioning

confidence: 99%

“…In this section, we begin by adapting the schematic diagrams first presented in Leigh & Geller (2012) to depict individual snapshots of the system in time for application to the general three-body problem, including arbitrarily long excursions of one of the particles, followed by a description of our method for discretizing the interaction.…”

Section: Constructing the Schematic Diagramsmentioning

confidence: 99%

Illustrating chaos: a schematic discretization of the general three-body problem in Newtonian gravity

Leigh

Wegsman

2018

Monthly Notices of the Royal Astronomical Society

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We present a formalism for constructing schematic diagrams to depict chaotic threebody interactions in Newtonian gravity. This is done by decomposing each interaction in to a series of discrete transformations in energy-and angular momentum-space. Each time a transformation is applied, the system changes state as the particles redistribute their energy and angular momenta. These diagrams have the virtue of containing all of the quantitative information needed to fully characterize most bound or unbound interactions through time and space, including the total duration of the interaction, the initial and final stable states in addition to every intervening temporary meta-stable state. As shown via an illustrative example for the bound case, prolonged excursions of one of the particles, which by far dominates the computational cost of the simulations, are reduced to a single discrete transformation in energy-and angular momentum-space, thereby potentially mitigating any computational expense. We further generalize our formalism to sequences of (unbound) three-body interactions, as occur in dense stellar environments during binary hardening. Finally, we provide a method for dynamically evolving entire populations of binaries via three-body scattering interactions, using a purely analytic formalism. In principle, the techniques presented here are adaptable to other three-body problems that conserve energy and angular momentum.

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Small-N collisional dynamics: pushing into the realm of not-so-small N

Cited by 51 publications

References 39 publications

MOCCA code for star cluster simulations – IV. A new scenario for intermediate mass black hole formation in globular clusters

MOCCA code for star cluster simulations – IV. A new scenario for intermediate mass black hole formation in globular clusters

Dynamical Processing of Stars and Planets Through Star Clusters

Illustrating chaos: a schematic discretization of the general three-body problem in Newtonian gravity

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