Institut national de recherche scientifique français Univerité Pierre et Marie Curie Université Paris Diderot - Paris 7

Gravito-turbulence in accretion disks : instabilities, spirals and locality

vendredi 21 janvier 2022, par William Béthune (University of Tübingen, Germany)

Jeudi 27 janvier 2022 à 15h30 , Lieu : En visioconférence

Spiral arms have been observed in a number of circumstellar disks. One plausible origin for these structures lies in the self-gravitating nature of the disk, when it is still massive relative to its central star. In this case, they may provide valuable constraints on the conditions of disk dispersal and planet formation, such as the disk mass, accretion rate, etc. However, they are often described as linear waves in razor-thin disks, and their role on the evolution of the disk is commonly reduced to an effective turbulent viscosity. I will look back at these approximations and examine their validity within global simulations of self-gravitating disks. I will discuss the deceptive nature of large-scale spiral arms, and the simple connections that can be made between their observable morphology and the physical conditions in the disk.