Monte-Carlo Stellar Dynamics near Massive Black Holes: Two-dimensional Fokker-Planck solutions of multiple mass components

TL;DR

This paper introduces GNC, a new Monte-Carlo code based on two-dimensional Fokker-Planck equations, to study the complex dynamical relaxation of multi-mass stellar clusters near supermassive black holes, including effects like resonant relaxation and gravitational waves.

Contribution

The paper presents the fundamental version of GNC, a flexible Monte-Carlo tool for simulating multi-mass stellar dynamics near black holes, incorporating advanced physics and improving statistical accuracy.

Findings

Consistent relaxation process results with previous studies.

Development of tangential anisotropy in cluster centers.

Outer regions remain near-isotropic.

Abstract

In this study we present a novel Monte-Carlo code, referred to as GNC, which enables the investigation of dynamical relaxation in clusters comprising multiple mass components in the vicinity of supermassive black holes at the centers of galaxies. Our method is based on two-dimensional Fokker-Planck equations in the energy and angular momentum space, and allows the evolution of multiple mass components, including stars and compact objects. The code demonstrates remarkable flexibility to incorporate additional complex dynamics, such as resonant relaxations and gravitational wave orbital decay. By employing a weighting method, we effectively enhance the statistical accuracy of rare particle results. In this initial publication, we present the fundamental version of our method, focusing on two-body relaxations and loss cone effects. Through comparisons with previous studies, we establish consistent outcomes in terms of relaxation processes, energy and angular momentum distributions, density profiles, and loss cone consumption rates. We consistently observe the development of tangential anisotropy within the cluster, while the outer regions tend to retain near-isotropic characteristics. Moving forward, GNC holds great promise for exploring a wide range of intriguing phenomena within galactic nuclei, in particular relativistic stellar dynamics, providing detailed and insightful outcomes.