What Drives the H i Content of Central Galaxies—A Comparison between Hydrodynamic Simulations and Observations Using Random Forest
We investigate the driving mechanisms for the H i gas content in star-forming central galaxies at low redshift, by examining the H i -to-stellar mass ratio ( M _H _i / M _* ) in both the state-of-the-art hydrodynamic simulations, IllustrisTNG (TNG) and EAGLE, and the xGASS sample. We quantify the co...
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2025-01-01
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| Online Access: | https://doi.org/10.3847/1538-4357/adace2 |
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| author | Xiao Li Cheng Li H. J. Mo |
| author_facet | Xiao Li Cheng Li H. J. Mo |
| author_sort | Xiao Li |
| collection | DOAJ |
| description | We investigate the driving mechanisms for the H i gas content in star-forming central galaxies at low redshift, by examining the H i -to-stellar mass ratio ( M _H _i / M _* ) in both the state-of-the-art hydrodynamic simulations, IllustrisTNG (TNG) and EAGLE, and the xGASS sample. We quantify the correlations of M _H _i / M _* with a variety of galaxy properties using the Random Forest regression technique, and we make comparisons between the two simulations, as well as between the simulations and xGASS. Gas-phase metallicity is found to be most important in both simulations, but is ranked mildly for xGASS, suggesting that metals and gas driven by feedback effects in real galaxies is not as tightly coupled as in the simulations. Beyond that, the accretion rate of supermassive black holes is the most important feature in TNG, while specific star formation rate is the top ranked in EAGLE. This result can be understood from the fact that the H i gas is regulated mainly by thermal-mode AGN feedback in TNG and by stellar feedback in EAGLE. Although neither simulation can fully reproduce the feature importance obtained for real galaxies in the xGASS, EAGLE performs better than TNG in the sense that the observationally top-ranked property, u − r , is also highly ranked in EAGLE. This result implies that stellar feedback plays a more dominant role than AGN feedback in driving the H i gas content of low-redshift galaxies. |
| format | Article |
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| institution | Kabale University |
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| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal |
| spelling | doaj-art-2194f5a113b54514aef2c494800f4ac72025-02-10T08:01:27ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01980114510.3847/1538-4357/adace2What Drives the H i Content of Central Galaxies—A Comparison between Hydrodynamic Simulations and Observations Using Random ForestXiao Li0https://orcid.org/0000-0002-2884-9781Cheng Li1https://orcid.org/0000-0002-8711-8970H. J. Mo2https://orcid.org/0000-0001-5356-2419Department of Astronomy, Tsinghua University , Beijing 100084, People’s Republic of China ; xli27938@gmail.com, cli2015@tsinghua.edu.cnDepartment of Astronomy, Tsinghua University , Beijing 100084, People’s Republic of China ; xli27938@gmail.com, cli2015@tsinghua.edu.cnDepartment of Astronomy, University of Massachusetts Amherst , MA 01003, USAWe investigate the driving mechanisms for the H i gas content in star-forming central galaxies at low redshift, by examining the H i -to-stellar mass ratio ( M _H _i / M _* ) in both the state-of-the-art hydrodynamic simulations, IllustrisTNG (TNG) and EAGLE, and the xGASS sample. We quantify the correlations of M _H _i / M _* with a variety of galaxy properties using the Random Forest regression technique, and we make comparisons between the two simulations, as well as between the simulations and xGASS. Gas-phase metallicity is found to be most important in both simulations, but is ranked mildly for xGASS, suggesting that metals and gas driven by feedback effects in real galaxies is not as tightly coupled as in the simulations. Beyond that, the accretion rate of supermassive black holes is the most important feature in TNG, while specific star formation rate is the top ranked in EAGLE. This result can be understood from the fact that the H i gas is regulated mainly by thermal-mode AGN feedback in TNG and by stellar feedback in EAGLE. Although neither simulation can fully reproduce the feature importance obtained for real galaxies in the xGASS, EAGLE performs better than TNG in the sense that the observationally top-ranked property, u − r , is also highly ranked in EAGLE. This result implies that stellar feedback plays a more dominant role than AGN feedback in driving the H i gas content of low-redshift galaxies.https://doi.org/10.3847/1538-4357/adace2Neutral hydrogen cloudsGalaxiesHydrodynamical simulationsInterstellar atomic gasGalaxy dark matter halosGalaxy evolution |
| spellingShingle | Xiao Li Cheng Li H. J. Mo What Drives the H i Content of Central Galaxies—A Comparison between Hydrodynamic Simulations and Observations Using Random Forest The Astrophysical Journal Neutral hydrogen clouds Galaxies Hydrodynamical simulations Interstellar atomic gas Galaxy dark matter halos Galaxy evolution |
| title | What Drives the H i Content of Central Galaxies—A Comparison between Hydrodynamic Simulations and Observations Using Random Forest |
| title_full | What Drives the H i Content of Central Galaxies—A Comparison between Hydrodynamic Simulations and Observations Using Random Forest |
| title_fullStr | What Drives the H i Content of Central Galaxies—A Comparison between Hydrodynamic Simulations and Observations Using Random Forest |
| title_full_unstemmed | What Drives the H i Content of Central Galaxies—A Comparison between Hydrodynamic Simulations and Observations Using Random Forest |
| title_short | What Drives the H i Content of Central Galaxies—A Comparison between Hydrodynamic Simulations and Observations Using Random Forest |
| title_sort | what drives the h i content of central galaxies a comparison between hydrodynamic simulations and observations using random forest |
| topic | Neutral hydrogen clouds Galaxies Hydrodynamical simulations Interstellar atomic gas Galaxy dark matter halos Galaxy evolution |
| url | https://doi.org/10.3847/1538-4357/adace2 |
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