Regulation of Star Formation by a Hot Circumgalactic Medium
Galactic outflows driven by supernovae (SNe) are thought to be a powerful regulator of a galaxy’s star-forming efficiency. Mass, energy, and metal outflows ( η _M , η _E , and η _Z , here normalized by the star formation rate, the SNe energy, and metal production rates, respectively) shape galaxy pr...
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IOP Publishing
2023-01-01
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Online Access: | https://doi.org/10.3847/1538-4357/acc4c7 |
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author | Christopher Carr Greg L. Bryan Drummond B. Fielding Viraj Pandya Rachel S. Somerville |
author_facet | Christopher Carr Greg L. Bryan Drummond B. Fielding Viraj Pandya Rachel S. Somerville |
author_sort | Christopher Carr |
collection | DOAJ |
description | Galactic outflows driven by supernovae (SNe) are thought to be a powerful regulator of a galaxy’s star-forming efficiency. Mass, energy, and metal outflows ( η _M , η _E , and η _Z , here normalized by the star formation rate, the SNe energy, and metal production rates, respectively) shape galaxy properties by both ejecting gas and metals out of the galaxy and by heating the circumgalactic medium (CGM), preventing future accretion. Traditionally, models have assumed that galaxies self-regulate by ejecting a large fraction of the gas, which enters the interstellar medium (ISM), although whether such high mass loadings agree with observations is still unclear. To better understand how the relative importance of ejective (i.e., high mass loading) versus preventative (i.e., high energy loading) feedback affects the present-day properties of galaxies, we develop a simple gas-regulator model of galaxy evolution, where the stellar mass, ISM, and CGM are modeled as distinct reservoirs which exchange mass, metals, and energy at different rates within a growing halo. Focusing on the halo mass range from 10 ^10 to 10 ^12 M _⊙ , we demonstrate that, with reasonable parameter choices, we can reproduce the stellar-to-halo mass relation and the ISM-to-stellar mass relation with low-mass-loaded ( η _M ∼ 0.1–10) but high-energy-loaded ( η _E ∼ 0.1–1) winds, with self-regulation occurring primarily through heating and cooling of the CGM. We show that the model predictions are robust against changes to the mass loading of outflows but are quite sensitive to our choice of the energy loading, preferring η _E ∼ 1 for the lowest-mass halos and ∼0.1 for Milky Way–like halos. |
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issn | 1538-4357 |
language | English |
last_indexed | 2024-03-12T04:12:59Z |
publishDate | 2023-01-01 |
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series | The Astrophysical Journal |
spelling | doaj.art-7e667a3ab5134daba1bf4cd450864a612023-09-03T10:51:19ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194912110.3847/1538-4357/acc4c7Regulation of Star Formation by a Hot Circumgalactic MediumChristopher Carr0https://orcid.org/0000-0002-5840-0424Greg L. Bryan1https://orcid.org/0000-0003-2630-9228Drummond B. Fielding2https://orcid.org/0000-0003-3806-8548Viraj Pandya3https://orcid.org/0000-0002-2499-9205Rachel S. Somerville4https://orcid.org/0000-0002-6748-6821Department of Astronomy, Columbia University , 550 West 120th Street, New York, NY 10027, USA ; cc4504@columbia.eduDepartment of Astronomy, Columbia University , 550 West 120th Street, New York, NY 10027, USA ; cc4504@columbia.edu; Center for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USACenter for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USACenter for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USA; Columbia Astrophysics Laboratory, Columbia University , 550 West 120th Street, New York, NY 10027, USACenter for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USAGalactic outflows driven by supernovae (SNe) are thought to be a powerful regulator of a galaxy’s star-forming efficiency. Mass, energy, and metal outflows ( η _M , η _E , and η _Z , here normalized by the star formation rate, the SNe energy, and metal production rates, respectively) shape galaxy properties by both ejecting gas and metals out of the galaxy and by heating the circumgalactic medium (CGM), preventing future accretion. Traditionally, models have assumed that galaxies self-regulate by ejecting a large fraction of the gas, which enters the interstellar medium (ISM), although whether such high mass loadings agree with observations is still unclear. To better understand how the relative importance of ejective (i.e., high mass loading) versus preventative (i.e., high energy loading) feedback affects the present-day properties of galaxies, we develop a simple gas-regulator model of galaxy evolution, where the stellar mass, ISM, and CGM are modeled as distinct reservoirs which exchange mass, metals, and energy at different rates within a growing halo. Focusing on the halo mass range from 10 ^10 to 10 ^12 M _⊙ , we demonstrate that, with reasonable parameter choices, we can reproduce the stellar-to-halo mass relation and the ISM-to-stellar mass relation with low-mass-loaded ( η _M ∼ 0.1–10) but high-energy-loaded ( η _E ∼ 0.1–1) winds, with self-regulation occurring primarily through heating and cooling of the CGM. We show that the model predictions are robust against changes to the mass loading of outflows but are quite sensitive to our choice of the energy loading, preferring η _E ∼ 1 for the lowest-mass halos and ∼0.1 for Milky Way–like halos.https://doi.org/10.3847/1538-4357/acc4c7Circumgalactic mediumGalactic windsGalaxiesGalaxy evolutionGalaxy physicsGalactic and extragalactic astronomy |
spellingShingle | Christopher Carr Greg L. Bryan Drummond B. Fielding Viraj Pandya Rachel S. Somerville Regulation of Star Formation by a Hot Circumgalactic Medium The Astrophysical Journal Circumgalactic medium Galactic winds Galaxies Galaxy evolution Galaxy physics Galactic and extragalactic astronomy |
title | Regulation of Star Formation by a Hot Circumgalactic Medium |
title_full | Regulation of Star Formation by a Hot Circumgalactic Medium |
title_fullStr | Regulation of Star Formation by a Hot Circumgalactic Medium |
title_full_unstemmed | Regulation of Star Formation by a Hot Circumgalactic Medium |
title_short | Regulation of Star Formation by a Hot Circumgalactic Medium |
title_sort | regulation of star formation by a hot circumgalactic medium |
topic | Circumgalactic medium Galactic winds Galaxies Galaxy evolution Galaxy physics Galactic and extragalactic astronomy |
url | https://doi.org/10.3847/1538-4357/acc4c7 |
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