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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Supermassive black holes in merger-free galaxies have higher spins which are preferentially aligned with their host galaxy
AU - Beckmann, R S
AU - Smethurst, R J
AU - Simmons, B D
AU - Coil, A
AU - Dubois, Y
AU - Garland, I L
AU - Lintott, C J
AU - Martin, G
AU - Peirani, S
AU - Pichon, C
PY - 2023/6/22
Y1 - 2023/6/22
N2 - Here we use the Horizon-AGN simulation to test whether the spins of SMBHs in merger-free galaxies are higher. We select samples using an observationally motivated bulge-to-total mass ratio of <0.1, along with two simulation-motivated thresholds selecting galaxies which have not undergone a galaxy merger since z = 2, and those SMBHs with $<10~{{\ \rm per\ cent}}$ of their mass due to SMBH mergers. We find higher spins (>5σ) in all three samples compared to the rest of the population. In addition, we find that SMBHs with their growth dominated by BH mergers following galaxy mergers, are less likely to be aligned with their galaxy spin than those that have grown through accretion in the absence of galaxy mergers (3.4σ). We discuss the implications this has for the impact of active galactic nuclei (AGN) feedback, finding that merger-free SMBHs spend on average 91 % of their lifetimes since z = 2 in a radio mode of feedback (88 % for merger-dominated galaxies). Given that previous observational and theoretical works have concluded that merger-free processes dominate SMBH-galaxy co-evolution, our results suggest that this co-evolution could be regulated by radio mode AGN feedback.
AB - Here we use the Horizon-AGN simulation to test whether the spins of SMBHs in merger-free galaxies are higher. We select samples using an observationally motivated bulge-to-total mass ratio of <0.1, along with two simulation-motivated thresholds selecting galaxies which have not undergone a galaxy merger since z = 2, and those SMBHs with $<10~{{\ \rm per\ cent}}$ of their mass due to SMBH mergers. We find higher spins (>5σ) in all three samples compared to the rest of the population. In addition, we find that SMBHs with their growth dominated by BH mergers following galaxy mergers, are less likely to be aligned with their galaxy spin than those that have grown through accretion in the absence of galaxy mergers (3.4σ). We discuss the implications this has for the impact of active galactic nuclei (AGN) feedback, finding that merger-free SMBHs spend on average 91 % of their lifetimes since z = 2 in a radio mode of feedback (88 % for merger-dominated galaxies). Given that previous observational and theoretical works have concluded that merger-free processes dominate SMBH-galaxy co-evolution, our results suggest that this co-evolution could be regulated by radio mode AGN feedback.
KW - Space and Planetary Science
KW - Astronomy and Astrophysics
U2 - 10.1093/mnras/stad1795
DO - 10.1093/mnras/stad1795
M3 - Journal article
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
ER -