The life cycle of circumnuclear gas discs in nearby galactic nuclei

Marc Schartmann, MPE Garching - 17.7.17



High-resolution observations from the sub-mm to the optical wavelength regime resolve the central few 100 pc region of nearby galaxies in great detail. Concentrating on the role circumnuclear discs play in the life cycles of galactic nuclei, we employ 3D adaptive mesh refinement hydrodynamical simulations with the Ramses code to self-consistently trace the evolution from a quasi-stable gas disc, undergoing gravitational (Toomre) instability, the formation of clumps and stars and the disc’s subsequent partial dispersal via stellar feedback. By comparing these simulations to available integral field unit observations of a sample of nearby galactic nuclei, we find consistent gas and stellar masses, kinematics, star formation and outflow properties. Important ingredients in the simulations are the self-consistent treatment of star formation and the dynamical evolution of the stellar distribution as well as the modelling of a delay time distribution for the supernova feedback. The knowledge of the resulting simulated density structure and kinematics on pc scale is vital for understanding inflow and feedback processes towards galactic scales. With the final aim of simulating full Seyfert activity cycles, we investigate radiation feedback from the central active nucleus onto the parsec scale environment in a separate project to understand the formation of gas and dust tori. By post-processing the simulations with radiative transfer simulations we are able to reproduce observations of the central, polar-elongated dust emission as recently found in interferometric observations.