Modeling Tidal Disruption Events and Compact Object Plunges in Nuclear Star Clusters

TL;DR

This study models tidal disruption events and compact object inspirals in nuclear star clusters with a focus on their impact on supermassive black hole growth, using advanced N-body simulations with improved physical models.

Contribution

The paper introduces two enhanced models for mass fallback and compact object plunges in N-body simulations, providing new insights into SMBH growth mechanisms in nuclear star clusters.

Findings

Mass accretion from TDEs peaks within 2 million years.

Higher initial SMBH masses lead to faster decline in TDE mass fallback.

Compact object accretion is limited to specific orbital pericenters and is reduced when inspiral criteria are applied.

Abstract

We study tidal disruption events (TDEs) and compact object inspirals in nuclear star clusters (NSCs) hosting a central supermassive black hole (SMBH), focusing on their role in SMBH growth. Using the STARDISK version of the direct N-body code NBODY6++GPU, we perform pilot simulations with two improved models: one for mass fallback from TDEs and another for compact object plunges based on orbital decay timescales. Our results show that mass accretion via TDEs peaks within the first 2 Myr and decreases more rapidly for higher initial SMBH masses, with roughly half the disrupted stellar debris being accreted. Compact object accretion is confined mostly to orbits with pericenters between 4 and 27 Schwarzschild radii and is suppressed by an order of magnitude when inspiral criteria are applied.