Black Hole Discs and Spheres in Galactic Nuclei -- Exploring the Landscape of Vector Resonant Relaxation Equilibria

Abstract

Vector resonant relaxation (VRR) is known to be the fastest gravitational process that shapes the geometry of stellar orbits in nuclear star clusters. This leads to the realignment of the orbital planes on the corresponding VRR time scale $t_{\mathrm{VRR}}$ of a few million years, while the eccentricity $e$ and semimajor axis $a$ of the individual orbits are approximately conserved. The distribution of orbital inclinations reaches an internal equilibrium characterised by two conserved quantities, the total potential energy among stellar orbits, $E_{\mathrm{tot}}$, and the total angular momentum, $L_{\mathrm{tot}}$. On timescales longer than $t_{\mathrm{VRR}}$, the eccentricities and semimajor axes change slowly and the distribution of orbital inclinations are expected to evolve through a series of VRR equilibria. Using a Monte Carlo Markov Chain method, we determine the equilibrium distribution of orbital inclinations in the microcanonical ensemble with fixed $E_{\mathrm{tot}}$ and $L_{\mathrm{tot}}$ for isolated nuclear star clusters with a power-law distribution of $a$, $e$, and $m$, where $m$ is the stellar mass. We explore the possible equilibria for $9$ representative $E_{\mathrm{tot}}$--$L_{\mathrm{tot}}$ pairs that cover the possible parameter space. For all cases, the equilibria show anisotropic mass segregation where the distribution of more massive objects is more flattened than that for lighter objects. Given that stellar black holes are more massive than the average main sequence stars, these findings suggest that black holes reside in disc-like structures within nuclear star clusters for a wide range of initial conditions.

arXiv commentVersion accepted for publication in MNRAS

References in corpus (70)

• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
• The Galactic Center Massive Black Hole and Nuclear Star Cluster
• Science with the space-based interferometer LISA. V: Extreme mass-ratio inspirals
• Formation of Galactic Nuclei
• Intermediate and Extreme Mass-Ratio Inspirals -- Astrophysics, Science Applications and Detection using LISA
• Rapid and Bright Stellar-mass Binary Black Hole Mergers in Active Galactic Nuclei
• Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole
• Gravitational waves from scattering of stellar-mass black holes in galactic nuclei
• Assisted Inspirals of Stellar Mass Black Holes Embedded in AGN Disks: Solving the "Final AU Problem"
• Resonant Relaxation in Stellar Systems
• Formation and Evolution of Compact Object Binaries in AGN Disks
• An Extremely Top-Heavy IMF in the Galactic Center Stellar Disks
• Nuclear Star Clusters
• A Disk of Young Stars at the Galactic Center as Determined by Individual Stellar Orbits
• Intermediate mass black holes in AGN disks: I. Production & Growth
• Stellar Populations in the Central 0.5 pc of the Galaxy II: The Initial Mass Function
• Event rate estimates for LISA extreme mass ratio capture sources
• Evidence for Warped Disks of Young Stars in the Galactic Center
• Resonant relaxation near a massive black hole: the stellar distribution and gravitational wave sources
• The Shortest Known Period Star Orbiting our Galaxy's Supermassive Black Hole
• A stellar census in globular clusters with MUSE: The contribution of rotation to cluster dynamics studied with 200 000 stars
• AGN as Potential Factories for Eccentric Black Hole Mergers
• Dissipationless Formation and Evolution of the Milky Way Nuclear Star Cluster
• Co-Evolution of Galactic Nuclei and Globular Cluster Systems
• Testing Properties of the Galactic Center Black Hole Using Stellar Orbits
• Properties of the Remnant Clockwise Disk of Young Stars in the Galactic Center
• Co-evolution of nuclear star clusters, massive black holes and their host galaxies
• Origin and growth of nuclear star clusters around massive black holes
• Resonant relaxation and the warp of the stellar disc in the Galactic centre
• Repeated Bursts from Relativistic Scattering of Compact Objects in Galactic Nuclei
• Rotating Globular Clusters
• On the distribution of stellar remnants around massive black holes: slow mass segregation, star cluster inspirals and correlated orbits
• A numerical study of vector resonant relaxation
• S62 and S4711: Indications of a population of faint fast moving stars inside the S2 orbit -- S4711 on a 7.6 year orbit around Sgr~A*
• In situ formation of SgrA* stars via disk fragmentation: parent cloud properties and thermodynamics
• MIKiS: the Multi-Instrument Kinematic Survey of Galactic Globular Clusters. I. Velocity dispersion profiles and rotation signals of 11 globular clusters
• Henize 2-10: the ongoing formation of a nuclear star cluster around a massive black hole
• Black Hole Disks in Galactic Nuclei
• On the rotation of nuclear star clusters formed by cluster-inspirals
• The efficiency of resonant relaxation around a massive black hole
• New constraints on the structure of the nuclear stellar cluster of the Milky Way from star counts and MIR imaging
• The young stars in the Galactic Center
• Age and mass segregation of multiple stellar populations in galactic nuclei and their observational signatures
• Stellar dynamical evidence against a cold disc origin for stars in the Galactic Centre
• The strong rotation of M5 (NGC 5904) as seen from the MIKiS Survey of Galactic Globular Clusters
• Kinematical evolution of tidally limited star clusters: rotational properties
• Kinematic Structure of the Galactic Center S-cluster
• Scalar Resonant Relaxation of Stars Around a Massive Black Hole
• Gamma-ray and X-ray emission from the Galactic Centre: hints on the nuclear star cluster formation history
• Isotropic-Nematic Phase Transitions in Gravitational Systems
• Relaxation in self-gravitating systems
• The complex kinematics of rotating star clusters in a tidal field
• Vector Resonant Relaxation of Stars around a Massive Black Hole
• The Gaia-ESO Survey: Dynamical models of flattened, rotating globular clusters
• The Kinematic Richness of Star Clusters I. Isolated Spherical Models with Primordial Anisotropy
• G2 can Illuminate the Black Hole Population near the Galactic Center
• The Thermodynamics of Rotating Black-Hole Star Clusters
• Isotropic-Nematic Phase Transitions in Gravitational Systems II: Higher Order Multipoles
• Star formation at the Galactic Centre: coevolution of multiple young stellar discs
• Anisotropic Mass Segregation in Rotating Globular Clusters
• Resonant relaxation in globular clusters
• A numerical study of stellar discs in galactic nuclei
• An order-disorder phase transition in black-hole star clusters
• Orbital alignment and mass segregation in galactic nuclei via vector resonant relaxation
• Central Dynamics of Multi-mass Rotating Star Clusters
• Order-disorder phase transition in black-hole star clusters -- III. A mono-energetic cluster
• Statistical Mechanics of Gravitational Systems with Regular Orbits: Rigid Body Model of Vector Resonant Relaxation
• Order-disorder phase transition in black-hole star clusters. II. A scale-free cluster
• Apsidal Clustering following the Inclination Instability

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