The History of Tidal Disruption Events in Galactic Nuclei

TL;DR

This paper investigates the long-term evolution of tidal disruption event rates in galactic nuclei using models and simulations, revealing how different star formation scenarios influence TDE history across cosmic time.

Contribution

It introduces a comprehensive analysis of TDE rate evolution over cosmic time, combining Fokker-Planck models and N-body simulations for various galaxy and star formation scenarios.

Findings

TDE rates increase over time in far-out star formation scenarios.

Close-in star formation leads to complex TDE rate behaviors.

Total TDE history can be probed with future large surveys like LSST.

Abstract

The tidal disruption of a star by a massive black hole (MBH) is thought to produce a transient luminous event. Such tidal disruption events (TDEs) may play an important role in the detection and characterization of MBHs and probe the properties and dynamics of their nuclear stellar clusters (NSCs) hosts. Previous studies estimated the recent rates of TDEs in the local universe. However, the long-term evolution of the rates throughout the history of the universe has been hardly explored. Here we consider the TDE history, using evolutionary models for the evolution of galactic nuclei. We use a 1D Fokker-Planck approach to explore the evolution of MBH-hosting NSCs, and obtain the disruption rates of stars during their evolution. We complement these with an analysis of TDEs history based on N-body simulation data, and find them to be comparable. We consider NSCs that are built-up from close-in star-formation (SF) or from SF/clusters-dispersal far-out, a few pc from the MBH. We also explore cases where primordial NSCs exist and later evolve through additional star-formation/cluster-dispersal processes. We study the dependence of the TDE history on the type of galaxy, as well as the dependence on the MBH mass. These provide several scenarios, with a continuous increase of the TDE rates over time for cases of far-out SF and a more complex behavior for the close-in SF cases. Finally, we integrate the TDE histories of the various scenarios to provide a total TDE history of the universe, which can be potentially probed with future large surveys (e.g. LSST).