English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The escape mechanism of orbits in a star cluster rotating around its parentgalaxy in a circular orbit is investigated. A three degrees of freedom model isused for describing the dynamical properties of the Hamiltonian system. Thegravitational field of the star cluster is represented by a smooth andspherically symmetric Plummer potential. We distinguish between ordered andchaotic orbits as well as between trapped and escaping orbits, considering onlyunbounded motion for several energy levels. The Smaller Alignment Index (SALI)method is used for determining the regular or chaotic nature of the orbits. Thebasins of escape are located and they are also correlated with thecorresponding escape time of the orbits. Areas of bounded regular or chaoticmotion and basins of escape were found to coexist in the $(x,z)$ plane. Theproperties of the normally hyperbolic invariant manifolds (NHIMs), located inthe vicinity of the index-1 Lagrange points $L_1$ and $L_2$, are also explored.These manifolds are of paramount importance as they control the flow of starsover the saddle points, while they also trigger the formation of tidal tailsobserved in star clusters. Bifurcation diagrams of the Lyapunov periodic orbitsas well as restrictions of the Poincar\'e map to the NHIMs are deployed forelucidating the dynamics in the neighbourhood of the saddle points. Theextended tidal tails, or tidal arms, formed by stars with low velocity whichescape through the Lagrange points are monitored. The numerical results of thiswork are also compared with previous related work.

Unraveling the escape dynamics and the nature of the normally hyperbolic invariant manifolds in tidally limited star clusters