ArkenstoneBH. A model for high-specific energy black hole feedback in cosmological simulations

TL;DR

The paper introduces ArkenstoneBH, a new subgrid model for simulating high-specific-energy black hole feedback in galaxy evolution, demonstrating its effectiveness in suppressing star formation in isolated galaxy simulations.

Contribution

It extends the Arkenstone framework to model black hole feedback, focusing on the hot, high-energy phase of outflows in coarse resolution simulations.

Findings

Arkenstone BH captures high-energy outflows interacting weakly with cold gas.

The model suppresses star formation by counteracting gas inflow from the circumgalactic medium.

Demonstrates the framework's ability in isolated galaxy simulations.

Abstract

AGN feedback is a key piece of galaxy evolution but is difficult to model due to its high specific energies, multiphase nature, and limited simulation resolutions. Arkenstone is a subgrid framework for representing multiphase flows in coarse resolution simulations that has been used to model stellar feedback driven galactic winds. It ensures the correct treatment of high specific energy feedback that would otherwise be challenging to model accurately in Lagrangian simulations. We introduce the new Arkenstone BH model, which extends the Arkenstone framework to model black hole feedback. We focus on describing the first piece of this framework, which follows the hot, high specific energy phase of these outflows. The second piece, which treats their multiphase structure with a scheme for modeling unresolved cold clouds, will be implemented and described in a later paper. We present Arkenstone BH in simulations of an isolated galaxy to demonstrate the framework and its ability to capture high specific energy feedback that interacts only weakly with cold, dense gas. We show how these energetic outflows suppress star formation in our isolated galaxy by counteracting the inflow of gas from the circumgalactic medium into the interstellar medium. This work is part of the "Learning the Universe" collaboration, which aims to understand the Universe's underlying physics and initial conditions.