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

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 MOKA3D, 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.

Giant Biconical Dust Filaments in the Starburst Galaxy NGC 1808

“…The filamentary morphology is expected of an evacuated cone, where the column density along the line of sight is highest along the edges of the cones due to projection effects. If this were a filled cone, the emission would be strongest along the cone axis and become fainter farther away from this axis (e.g., Veilleux et al 2001;Marconcini et al 2023). This structure overlaps with the kiloparsec-scale dusty filaments visible in the optical broadband (B − R) color maps of Phillips (1993), but it extends to a much larger scale.…”

“…This structure overlaps with the kiloparsec-scale dusty filaments visible in the optical broadband (B − R) color maps of Phillips (1993), but it extends to a much larger scale. Edge-brightened conical structures are seen in a number of starburst-and AGN-driven outflows (e.g., Veilleux et al 2001;Marconcini et al 2023).…”