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Black holes regulate cool gas accretion in massive galaxies
Tao Wang1,2, Ke Xu3,4, Yuxuan Wu3,4
1School of Astronomy and Space Science, Nanjing University, Nanjing, China. taowang@nju.edu.cn.
Nature
|August 14, 2024
Summary
Supermassive black holes (BHs) significantly regulate galaxy gas content. Their mass is the primary driver of atomic hydrogen (HI) gas levels, influencing galaxy evolution by ejecting or suppressing gas cooling.
Area of Science:
- Astrophysics
- Galaxy Evolution
- Black Hole Physics
Background:
- Massive galaxies host supermassive black holes (BHs).
- BH feedback is theorized to regulate galaxy quiescence, but its influence on star formation is debated.
- Direct evidence linking BHs to galaxy gas content is lacking.
Purpose of the Study:
- To investigate the direct influence of supermassive black hole mass on galaxy gas reservoirs.
- To determine the primary driver of atomic hydrogen (HI) gas content in massive galaxies.
- To provide evidence for BH feedback mechanisms regulating cool gas.
Main Methods:
- Analyzed a large sample of nearby galaxies with measured BH and atomic hydrogen (HI) masses.
- Calculated the HI gas mass to stellar mass ratio (μHI).
- Correlated μHI with BH mass (MBH) and other galaxy parameters (stellar mass, surface density, bulge mass).
Main Results:
- The HI gas mass to stellar mass ratio (μHI) shows the strongest correlation with BH mass (MBH).
- MBH is identified as the primary driver of μHI, overriding other galaxy parameters.
- This correlation holds true across various galaxy types and environments.
Conclusions:
- Supermassive black hole mass is a key factor in regulating the cool gas content of galaxies.
- BH accretion energy likely ejects interstellar medium gas or suppresses circumgalactic medium gas cooling.
- These findings offer direct evidence for BH feedback influencing galaxy gas reservoirs and star formation.
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