Gas Flows in the Central Regions of NGC 4593 with Muse

Mulumba, Dorcus; Knapen, Johan; Comerón, Sebastien
Bibliographical reference

EAS2024

Advertised on:
7
2024
Number of authors
3
IAC number of authors
1
Citations
0
Refereed citations
0
Description
Gas flows into the centres of galaxies form an important ingredient to the formation, growth and evolution of galaxies. The process of gas falling into the central supermassive black hole (SMBH) can lead to high levels of non-stellar emission which results in an active galactic nucleus (AGN). However, the details of how such gas flows reach the centre of a galaxy and how they in turn affect their surroundings through feedback is not well understood, despite ongoing research. We use MUSE-AO optical spectra of the inner 7.5x7.5 arcsec^2 of the nearby Seyfert 1 galaxy NGC 4593 to understand how gas flows in and out of its nuclear region. We determine the stellar velocity and velocity dispersion and fit single-component Gaussians to various emission lines like [O iii] λ5007, [N ii]λ6583, Hα and Hβ to determine the main ionisation mechanism through resolved BPT diagrams. We also fit two-component Gaussians to [O iii]λ5007 to disentangle the disc emission from that of the outflow. The high resolution MUSE data capture structures of the circumnuclear region including the innermost spiral feeding the nucleus. We find that the outflow component is broad, with high velocity dispersion values of 250 km/s ‑ 300 km/s which indicates that the gas is highly perturbed. The emission line flux ratio maps show that the innermost 2'' (376 pc) are highly ionised by the AGN, while the emission line kinematic maps show the approaching side of a presumably bi-conic outflow. We estimate the mass-outflow rates and kinetic powers as Ṁ = 0.046M⊙ /yr and Ėkin =5.48 × 10^39 erg/s respectively. It is expected that high resolution IFU observations can enable multi-component analysis allowing a detailed view of ionised gas flows.