Abstract
Supermassive black holes (SMBHs) that reside at the centres of galaxies can inject vast amounts of energy into the surrounding gas and are thought to be a viablemechanism to quench star formation inmassive galaxies. Here, we study the 109-12.5M⊙stellar mass central galaxy population of the IllustrisTNG simulation, specifically the TNG100 and TNG300 volumes at z =0, and show how the three components - SMBH, galaxy, and circumgalactic medium (CGM) - are interconnected in their evolution.We find that gas entropy is a sensitive diagnostic of feedback injection. In particular, we demonstrate how the onset of the low-accretion black hole (BH) feedback mode, realized in the IllustrisTNG model as a kinetic, BH-driven wind, leads not only to star formation quenching at stellar masses ≥ 1010.5M⊙but also to a change in thermodynamic properties of the (non-star-forming) gas, both within the galaxy and beyond. The IllustrisTNG kinetic feedback from SMBHs increases the average gas entropy, within the galaxy and in the CGM, lengthening typical gas cooling times from 10-100 Myr to 1-10Gyr, effectively ceasing ongoing star formation and inhibiting radiative cooling and future gas accretion. In practice, the same active galactic nucleus (AGN) feedback channel is simultaneously 'ejective' and 'preventative' and leaves an imprint on the temperature, density, entropy, and cooling times also in the outer reaches of the gas halo, up to distances of several hundred kiloparsecs. In the IllustrisTNG model, a long-lasting quenching state can occur for a heterogeneous CGM, whereby the hot and dilute CGM gas of quiescent galaxies contains regions of low-entropy gas with short cooling times.
Original language | American English |
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Pages (from-to) | 768-792 |
Number of pages | 25 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 499 |
Issue number | 1 |
DOIs | |
State | Published - 1 Nov 2020 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors thank the anonymous referee for their time and effort in providing constructive comments and suggestions which improved the paper. The authors would like to thank Martina Donnari for input on the star formation rates of TNG galaxies and for many fruitful discussions. FM acknowledges support through the Program ‘Rita Levi Montalcini’ of the Italian MIUR. MV acknowledges support through an MIT RSC award, a Kavli Research Investment Fund, NASA ATP grant NNX17AG29G, and NSF grants AST-1814053, AST-1814259, and AST-1909831. The flagship simulations of the IllustrisTNG project used in this work (TNG100 and TNG300) have been run on the HazelHen Cray XC40-system at the High
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Keywords
- Galaxies: evolution
- Galaxies: haloes
- Galaxies: star formation
- Quasars: supermassive black holes