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SUMMARY:Small hosts\, big appetites: unveiling rapid and early low-mass bl
 ack hole growth in cosmological zoom-in simulations of dwarf galaxies - Gi
 ulia Ortame
DTSTART:20260218T131500Z
DTEND:20260218T134000Z
UID:TALK244867@talks.cam.ac.uk
CONTACT:Cristiano Longarini
DESCRIPTION:\n\nDwarf galaxies are ideal laboratories to probe the interpl
 ay between galaxy formation and the growth of black holes (BHs) in the ear
 ly Universe. Mounting observational evidence reveals the presence of BHs i
 n low-mass galaxies across cosmic time\, with JWST uncovering a likely pop
 ulation of overmassive BHs at 2 ≲ z ≲ 11. Simulations struggle to repr
 oduce this high-redshift regime\, motivating revisions to BH accretion and
  active galactic nucleus (AGN) feedback modelling. We present high-resolut
 ion cosmological zoom-in simulations of a dwarf galaxy based on FABLE phys
 ics\, introducing novel sink-based BH accretion models and relaxing the fi
 ducial assumption of strong supernova feedback. BHs accrete more efficient
 ly in the sink-based runs compared to the ‘traditional’ Bondi-based co
 unterparts\, while the impact of AGN feedback on star formation ranges fro
 m negligible to early (z ≳ 2) and rapid quenching maintained by fast\, h
 ot outflows down to z = 0. We further assess the performance of two widely
  used dynamical mass estimators and find significant departures from the t
 rue dynamical mass\, especially during the high-redshift dwarf assembly. S
 ince our galaxy is dark-matter-dominated at all times and radii\, BH growt
 h\, tied to the baryon cycle\, shows no clear correlation with global dyna
 mical properties. Simulations with efficient AGN feedback yield overmassiv
 e BHs relative to extrapolated local BH mass − stellar mass scaling rela
 tions\, hinting at a potential connection between dormant BHs in local dwa
 rfs and high-redshift JWST BHs. High-redshift feedback from rapidly assemb
 led\, overmassive BHs drives metal-enriched outflows that pollute the oute
 r circumgalactic medium\, leading to flat metallicity gradients that persi
 st down to z = 0.\n
LOCATION:Hoyle Lecture theatre + Zoom 
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