  Outflows accelerated by AGN are commonly observed in the form of coherent,
mildly collimated high-velocity gas directed along the AGN ionisation cones and
kinetically powerful (>$10^{44-45}$ erg/s) jets. Recent works found that
outflows can also be accelerated by low-power (<$10^{44}$ erg/s) jets, and the
most recent cosmological simulations indicate that these are the dominant
source of feedback on sub-kpc scales. We study the relation between radio jets
and the distribution and kinematics of the ionised gas in IC 5063, NGC 5643,
NGC 1068, and NGC 1386 as part of our MAGNUM survey of nearby Seyfert galaxies.
All these objects host a small-scale (<1 kpc) low-power (<$10^{44}$ erg/s)
radio jet that has small inclinations (<45\deg) with respect to the galaxy
disc. We employed seeing-limited optical integral field spectroscopic
observations from MUSE at VLT to obtain flux, kinematic, and excitation maps of
the extended ionised gas, that we compared with archival radio images and
Chandra X-ray observations. We detect a strong (up to >800-1000 km/s), extended
(>1 kpc) and shock-excited emission-line velocity spread perpendicular to the
AGN ionisation cones and jets in all four targets. These broad and symmetric
line profiles are not associated with a single coherent velocity of the gas,
differently from the 'classical' asymmetric-line outflow observed along the
ionisation cones and jets. We interpret the observed phenomenon as due to the
action of the jets perturbing the gas in the galaxy disc. These intense and
extended velocity spreads perpendicular to AGN jets and cones are indeed
currently only observed in galaxies hosting a low-power jet whose inclination
is sufficiently low with respect to the galaxy disc to impact on and strongly
affect its material. In line with cosmological simulations, our results
demonstrate that low-power jets are indeed capable of affecting the host
galaxy.
