  Recent observations and simulations have challenged the long-held paradigm
that mergers are the dominant mechanism driving the growth of both galaxies and
supermassive black holes (SMBH), in favour of non-merger (secular) processes.
In this pilot study of merger-free SMBH and galaxy growth, we use Keck Cosmic
Web Imager spectral observations to examine four low-redshift ($0.043 < z <
0.073$) disk-dominated `bulgeless' galaxies hosting luminous AGN, assumed to be
merger-free. We detect blueshifted broadened [OIII] emission from outflows in
all four sources, which the \oiii/\hbeta~ratios reveal are ionised by the AGN.
We calculate outflow rates in the range $0.12-0.7~\rm{M}_{\odot}~\rm{yr}^{-1}$,
with velocities of $675-1710~\rm{km}~\rm{s}^{-1}$, large radial extents of
$0.6-2.4~\rm{kpc}$, and SMBH accretion rates of
$0.02-0.07~\rm{M}_{\odot}~\rm{yr}^{-1}$. We find that the outflow rates,
kinematics, and energy injection rates are typical of the wider population of
low-redshift AGN, and have velocities exceeding the galaxy escape velocity by a
factor of $\sim30$, suggesting that these outflows will have a substantial
impact through AGN feedback. Therefore, 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. Simulations find that
bars and spiral arms can drive inflows to galactic centres at rates an order of
magnitude larger than the combined SMBH accretion and outflow rates of our four
targets. This work therefore provides further evidence that non-merger
processes are sufficient to fuel SMBH growth and AGN outflows in disk galaxies.
