Fast, dust-poor outflows in the local candidate dual AGN MCG-03-34-64 observed with VLT/ERIS

We present VLT/ERIS integral field unit (IFU) J-band observations of a nearby (z= 0. 0167) Seyfert galaxy hosting a candidate dual active galactic nucleus (AGN) system with a separation of sim100 pc between the nuclei, which are detected in X-ray images and narrow-band images. The ERIS observations cover, among others, the ̋eIłambda1. 083 and emission lines, over a field of view of 3'' (sim1 ∼-1700 ̨ms, which corresponds to the highest 2-5 percentiles of samples of local AGN with similar bolometric luminosities (kpc2). We analysed the ionised gas kinematics and identified two regions with an enhanced velocity dispersion (W80∼ 1500 ̨ms), which is suggestive of fast outflowing gas, spatially coincident with the position of the two candidate active nuclei. We extracted the spectra from the two regions and used them to derive the properties of the ionised outflows. The two spectra show a prominent blueshifted wing with velocities v_ max For the ionised phase of the two outflows, we derive comparable masses of ∼ (4 10⁵ and mass outflow rates of sim20 The two distinct outflows could be associated with the two nuclei or be generated by the interaction of the radio jet with the interstellar medium (ISM). The map of the line ratio shows the highest values in the more external regions (compatible with shock excitation), intermediate values in the vicinity of the nuclei (compatible with AGN excitation), and lower values between the two nuclei, close to the peak of the optical and near-infrared continuum. We interpret this as due to a contribution to the emission from a nuclear starburst or to enhanced AGN ionisation. We also analysed the peculiar (very broad, boxy) profile of the optical coronal line from an archival VLT/X-shooter spectrum. The comparison with the and profiles indicates that emission likely arises only from the outflow. The absence of the systemic component in -- unlike in which has similar ionisation potential and critical density -- suggests suppression of due to iron depletion onto dust grains, while its detection in the outflow implies a lower dust content than in the host ISM. The additional information gained from the ERIS data are consistent with the scenario of a dual AGN, however, further observations are required to confirm its nature.