Large-Scale Features of the CON Galaxy NGC4418 with MUSE

TL;DR

This study uses MUSE observations to map the optical spectral features and kinematics of the CON galaxy NGC4418, revealing outflows and structures that suggest an AGN as the power source.

Contribution

First spatially resolved optical mapping of NGC4418's spectral features and outflows, providing new insights into the nature of compact obscured nuclei.

Findings

Discovery of bilateral outflow along the minor axis

Identification of an outflowing bubble and knot structures

Evidence supporting an AGN as the central power source

Abstract

Compact obscured nuclei (CONs) are relatively common in the centers of local (U)LIRGs, yet their nature remains unknown. Both AGN activity and extreme nuclear starbursts have been suggested as plausible nuclear power sources. The prevalence of outflows in these systems suggest that CONs represent a key phase in the nuclear feedback cycle, in which material is ejected from the central regions of the galaxy. Here, we present results from MUSE for the confirmed local CON galaxy NGC4418. For the first time we spatially map the spectral features and kinematics of the galaxy in the optical, revealing several previously unknown structures. In particular, we discover a bilateral outflow along the minor axis, an outflowing bubble, several knot structures and a receding outflow partially obscured by the galactic disk. Based on the properties of these features, we conclude that the CON in NGC4418 is most likely powered by an AGN.