A census of kinematic asymmetries in dark matter dominated galactic discs – Laurent Chemin

Low mass surface density (LSD) galaxies are the most appropriate galaxies to study the structure of darkmatter (DM). Among them, LSD discs are at the origin of a controversy with ΛCDM modelings: the inner shape of their rotation curve is not as steep as those of simulated discs. It has been argued that the origin of this controversy comes from kinematic asymmetries that could hide the cosmological cusp into a core dominated DM halo. However, the search for significant kinematic asymmetries in LSD has been unsuccessful until now. Here, I will present results from an ongoing survey of ionized gas in LSD by means of Fabry-Perot interferometry. The main goals of this work are to get high-resolution velocity fields and rotation curves, and make a new census of kinematic asymmetries in LSD. In particular, I will show that the observed amount of asymmetric and non-circular motions is larger than quoted in previous studies, and discuss their impact on the mass distribution models of LSD, thus on the current controversy. I will also show how random motions of gas in galaxies are helpful to find the nature of dominant asymmetries in the disc.

Horarios: June 27, 2023 15:30

Publicado por: Claudia Aguilera