MOKA^3D: An innovative approach to 3D gas kinematic modelling

I. Application to AGN ionised outflows

¹ Dipartimento di Fisica e Astronomia, Universitá degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
e-mail: cosimo.marconcini@unifi.it
² INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
e-mail: cosimo.marconcini@inaf.it
³ Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
⁴ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
⁵ INAF, Padova Astronomical Observatory, Vicolo Osservatorio 5, 35122 Padova, Italy
⁶ Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
⁷ Department of Physics, University of Arkansas, 226 Physics Building, 825 West Dickson Street, Fayetteville, AR 72701, USA
⁸ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA

Received: 5 May 2023
Accepted: 4 July 2023

Abstract

Studying the feedback process of active galactic nuclei (AGN) requires the characterisation of multiple kinematical components, such as rotating gas and stellar discs, outflows, inflows, and jets. The usual approach to compare the observed galaxy properties with feedback theoretical predictions relies on simplified kinematic models. This allows us to assess the mutual interaction between the galaxy components and determine the energy injection rate into the interstellar medium. However, these models have several limitations, as they often do not take into account projection effects, beam smearing, or the surface brightness distribution of the emitting medium. Here, we present MOKA^3D, an innovative approach to modelling the 3D gas kinematics from integral field spectroscopy observations. In this first paper, we discuss its application to the case of AGN ionised outflows, whose observed clumpy emission and apparently irregular kinematics are only marginally accounted for by the existing kinematical models. Unlike previous works, our model does not assume the surface brightness distribution of the gas, but exploits a novel procedure to derive it from observations by reconstructing the 3D distribution of emitting clouds and providing accurate estimates of the physical properties of spatially resolved outflow (e.g., mass rate, kinetic energy). We demonstrate the capabilities of our method by applying it to three nearby Seyfert-II galaxies observed with the Multi Unit Spectroscopic Explorer (MUSE) at the VLT and selected from the Measuring Active Galactic Nuclei Under MUSE Microscope (MAGNUM) survey, showing that the complex kinematic features observed can be described by a conical outflow with a constant radial velocity field and a clumpy distribution of clouds.