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...

Full description

Bibliographic Details
Main Authors: Christopher Carr, Greg L. Bryan, Drummond B. Fielding, Viraj Pandya, Rachel S. Somerville
Format: Article
Language:English
Published: IOP Publishing 2023-01-01
Series:The Astrophysical Journal
Subjects:
Online Access:https://doi.org/10.3847/1538-4357/acc4c7
_version_ 1797699793734074368
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.
first_indexed 2024-03-12T04:12:59Z
format Article
id doaj.art-7e667a3ab5134daba1bf4cd450864a61
institution Directory Open Access Journal
issn 1538-4357
language English
last_indexed 2024-03-12T04:12:59Z
publishDate 2023-01-01
publisher IOP Publishing
record_format Article
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
work_keys_str_mv AT christophercarr regulationofstarformationbyahotcircumgalacticmedium
AT greglbryan regulationofstarformationbyahotcircumgalacticmedium
AT drummondbfielding regulationofstarformationbyahotcircumgalacticmedium
AT virajpandya regulationofstarformationbyahotcircumgalacticmedium
AT rachelssomerville regulationofstarformationbyahotcircumgalacticmedium