Planetary Systems in a Star Cluster II: intermediate-mass black holes and planetary systems

Abstract

Most stars form in dense stellar environments. It is speculated that some dense star clusters may host intermediate-mass black holes (IMBHs), which may have formed from runaway collisions between high-mass stars, or from the mergers of less massive black holes. Here, we numerically explore the evolution of populations of planets in star clusters with an IMBH. We study the dynamical evolution of single-planet systems and free-floating planets, over a period of 100~Myr, in star clusters without an IMBH, and in clusters with a central IMBH of mass $100M_{\odot }$ or $200M_{\odot }$. In the central region ($r\lesssim 0.2$~pc), the IMBH's tidal influence on planetary systems is typically 10~times stronger than the average neighbour star. For a star cluster with a $200M_{\odot }$ IMBH, the region in which the IMBH's influence is stronger within the virial radius ($\sim 1$~pc). The IMBH quenches mass segregation, and the stars in the core tend to move towards intermediate regions. The ejection rate of both stars and planets is higher when an IMBH is present. The rate at which planets are expelled from their host star rate is higher for clusters with higher IMBH masses, for $t<0.5t_{rh}$, while remains mostly constant while the star cluster fills its Roche lobe, similar to a star cluster without an IMBH. The disruption rate of planetary systems is higher in initially denser clusters, and for wider planetary orbits, but this rate is substantially enhanced by the presence of a central IMBH.

17 Pages, 39 Figures, accepted for pubblication on Monthly Notices of the Royal Astronomical Society on date 14 July 2020

References in corpus (12)

• Multi-messenger Observations of a Binary Neutron Star Merger
• No large population of unbound or wide-orbit Jupiter-mass planets
• Stellar remnants in galactic nuclei: mass segregation
• Dynamics of Planetary Systems in Star Clusters
• Close encounters in young stellar clusters: implications for planetary systems in the solar neighbourhood
• The core binary fractions of star clusters from realistic simulations
• Ratios of star cluster core and half-mass radii: a cautionary note on intermediate-mass black holes in star clusters
• A comprehensive Nbody study of mass segregation in star clusters: Energy equipartition and escape
• Substellar Objects in Nearby Young Clusters (SONYC) VI: The planetary-mass domain of NGC1333
• Evidence for an intermediate-mass black hole in the globular cluster NGC 6624
• Intermediate Mass Black Hole Induced Quenching of Mass Segregation in Star Clusters
• Close encounters involving free-floating planets in star clusters

Cited by in corpus (1)

• Stability of planetary systems within the S-star cluster: the Solar system analogues