Researchers Matas Tartėnas, Kastytis Zubovas, and Eimantas Skuodas from the University of Leicester have been investigating the complex interactions between supermassive black holes (SMBHs) and their host galaxies. Their work, published in the journal Monthly Notices of the Royal Astronomical Society, sheds light on how these interactions can lead to the well-known empirical relationship between the mass of a SMBH and the velocity dispersion of the stars in the host galaxy’s bulge, known as the M-σ relation.
The M-σ relation is often attributed to the self-regulation of SMBH growth through active galactic nucleus (AGN) feedback. In simpler terms, as a SMBH grows, it can expel gas from its host galaxy, thereby limiting its own growth. However, previous models have relied on idealized conditions, such as smooth gas distributions and efficient cooling of the shocked AGN wind.
To better understand these processes, the researchers conducted a series of hydrodynamical simulations of AGN outflows in turbulent gas shells, covering a wide range of constant AGN luminosities. They tracked the evolution of these outflows over the course of at least one million years, analyzing the effect of AGN outflow on the cold dense gas and SMBH feeding.
Their findings indicate that AGNs with significantly sub-Eddington luminosities (less than about 0.7 times the Eddington luminosity) cannot suppress SMBH feeding. However, AGNs with luminosities exceeding this threshold can clear out both the diffuse hot gas and the cold clumps, consistent with the momentum-driven outflow formalism. The researchers also showed that dense gas clusters are primarily affected by the AGN wind momentum, while the shocked wind energy escapes through low-density channels and inflates large bubbles of diffuse gas.
In practical terms for the energy sector, understanding these processes can help inform the development of more accurate models of galaxy evolution and the growth of SMBHs. This, in turn, can contribute to our understanding of the universe’s energy dynamics and the role of black holes in shaping the cosmos. While this research may not have direct applications in energy production or consumption, it contributes to the broader scientific understanding of cosmic phenomena, which can indirectly influence various fields, including energy research.
Source: Tartėnas, M., Zubovas, K., & Skuodas, E. (2022). Simple relations from complex outflows: How the M-σ relation emerges in a multi-phase environment. Monthly Notices of the Royal Astronomical Society, 511(3), 3647-3662.
This article is based on research available at arXiv.