Year: 2024
Type: article
Abstract: This paper presents a new framework for understanding the relationship between a galaxy and its circumgalactic medium (CGM). It focuses on how imbalances between heating and cooling cause either expansion or contraction of the CGM. It does this by tracking all of the mass and energy associated with a halo’s baryons, including their gravitational potential energy, even if feedback has pushed some of those baryons beyond the halo’s virial radius. We show how a star-forming galaxy’s equilibrium state can be algebraically derived within the context of this framework, and we analyze how the equilibrium star formation rate depends on supernova feedback. We consider the consequences of varying the mass loading parameter η M ≡ M ̇ wind / M ̇ * relating a galaxy’s gas mass outflow rate ( M ̇ wind ) to its star formation rate ( M ̇ * ) and obtain results that challenge common assumptions. In particular, we find that equilibrium star formation rates in low-mass galaxies are generally insensitive to mass loading, and when mass loading does matter, increasing it actually results in more star formation because more supernova energy is needed to resist atmospheric contraction.
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Awards: G1380475623, G1674337922, Baryon Cycles in the Biggest Galaxies, Turning up the Heat: Using Ram Pressure Stripping in Clusters to Understand Star Formation in Extreme Conditions, G3398237449, G3981263901, Constraining satellite-host galaxy co-evolution with next-generation semi-analytic models, G433322167, G4689434848, G58316358, G6233126168, G6273510985, Kavli Institute for Theoretical Physics, G8254390020, G8499723490, G8512485452, G908066236
OpenAlex ID: W4404532015