The growth of supermassive black holes in the absence of mergers and the effect on their host galaxies

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• Rebecca Smethurst (University of Oxford)
• Friday 11 March 2022, 11:30-12:30
• via zoom .

If you have a question about this talk, please contact Ricarda Beckmann.

The co-evolution of galaxies and their supermassive black holes (SMBHs) dominated by mergers is a long-held paradigm that has recently been overturned. With a sample of `bulgeless’ disk-dominated galaxies Simmons, Smethurst & Lintott (2017) showed that in the absence of mergers, SMBHs can grow to 10^9 solar masses. A follow up study by Martin et al. (2018) found that in simulations, 65% of all the matter contained in SMB Hs at z<sub>0 was acquired through non-merger processes. We now present detailed KCWI IFU observations of the [OIII] 5007 Å component for 4 of these `bulgeless’ disk-dominated galaxies hosting luminous, unobscured AGN with spectrally confirmed blue shifted outflows, presumed to be powered by the AGN  itself. These massive galaxies’ formation histories are dominated by non-merger secular processes and thus provide a unique opportunity to study how inflows from secular processes fuel significant growth of black holes in the absence of significant mergers. We calculate outflow rates for these AGN in the range 0.12 − 0.7 M_sun/yr, with velocities of 675 − 1710 km/s, large maximum radial extents of 0.6 − 2.4 kpc, and SMBH  accretion rates of 0.02 − 0.07 M_sun/yr. We find that the outflow rates, kinematics, and energy injection rates are typical of the wider population of low-redshift AGN , and have velocities that exceed the galaxy escape velocity by a factor of</sub> 30, suggesting that these outflows will have a substantial impact on their galaxies through AGN feedback. This has interesting implications: if both merger-driven and non-merger-driven SMBH growth lead to co-evolution, this suggests that co-evolution is regulated by feedback in both scenarios.

This talk is part of the Galaxies Discussion Group series.

This talk is included in these lists:

• Combined External Astrophysics Talks DAMTP
• Cosmology, Astrophysics and General Relativity
• Galaxies Discussion Group
• Institute of Astronomy Talk Lists
• Kavli Institute for Cosmology Talk Lists
• via zoom

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