Spin-driven jet feedback in idealised simulations of galaxy groups and clusters

TL;DR

This study introduces a black hole spin evolution and jet feedback model into a simulation code, demonstrating how jet activity influences gas cooling and star formation in galaxy groups and clusters across different mass scales.

Contribution

The paper presents a novel implementation of spin-dependent jet feedback in SPH simulations, capturing jet reorientation and its effects on galaxy evolution.

Findings

Jet feedback quenches star formation in galaxy groups and clusters.

Massive systems experience multiple cooling and feedback episodes.

Strong jets can temporarily suppress cooling flows and star formation.

Abstract

We implement a black hole spin evolution and jet feedback model into SWIFT, a smoothed particle hydrodynamics code. The jet power is determined self-consistently assuming Bondi accretion, using a realistic, spin-dependant efficiency. The jets are launched along the spin axis of the black hole, resulting in natural reorientation and precession. We apply the model to idealised simulations of galaxy groups and clusters, finding that jet feedback successfully quenches gas cooling and star formation in all systems. Our group-size halo ($M_\mathrm{200}=10^{13}$ $\mathrm{M}_\odot$) is quenched by a strong jet episode triggered by a cooling flow, and it is kept quenched by a low-power jet fed from hot halo accretion. In more massive systems ($M_\mathrm{200}\geq 10^{14}$ $\mathrm{M}_\odot$), hot halo accretion is insufficient to quench the galaxies, or to keep them quenched after the first cooling episode. These galaxies experience multiple episodes of gas cooling, star formation and jet feedback. In the most massive galaxy cluster that we simulate ($M_\mathrm{200}=10^{15}$ $\mathrm{M}_\odot$), we find peak cold gas masses of $10^{10}$ $\mathrm{M}_\odot$ and peak star formation rates of a few times $100$ $\mathrm{M}_\odot\mathrm{yr}^{-1}$. These values are achieved during strong cooling flows, which also trigger the strongest jets with peak powers of $10^{47}$ $\mathrm{erg}\hspace{0.3mm}\mathrm{s}^{-1}$. These jets subsequently shut off the cooling flows and any associated star formation. Jet-inflated bubbles draw out low-entropy gas that subsequently forms dense cooling filaments in their wakes, as seen in observations.