  How galaxies regulate nuclear growth through gas accretion by supermassive
black holes (SMBHs) is one of the most fundamental questions in galaxy
evolution. One potential way to regulate nuclear growth is through a galactic
wind that removes gas from the nucleus. It is unclear whether galactic winds
are powered by jets, mechanical winds, radiation, or via magnetohydrodynamic
(MHD) processes. Compact obscured nuclei (CONs) represent a significant phase
of galactic nuclear growth. These galaxies hide growing SMBHs or unusual
starbursts in their very opaque, extremely compact (r $<$ 100 pc) centres. They
are found in approximately 30 % of the luminous and ultra-luminous infrared
galaxy (LIRG and ULIRG) population. Here, we present high-resolution ALMA
observations ($\sim$30 mas, $\sim$5 pc) of ground-state and vibrationally
excited HCN towards ESO 320-G030 (IRAS 11506-3851). ESO 320-G030 is an isolated
luminous infrared galaxy known to host a compact obscured nucleus and a
kiloparsec-scale molecular wind. Our analysis of these high-resolution
observations excludes the possibility of a starburst-driven wind, a
mechanically or energy driven active galactic nucleus (AGN) wind, and exposes a
molecular MDH wind. These results imply that the nuclear evolution of galaxies
and the growth of SMBHs are similar to the growth of hot cores or protostars
where gravitational collapse of the nuclear torus drives a MHD wind. These
results mean galaxies are capable, in part, of regulating the evolution of
their nuclei without feedback.
