Thinkshop 2020

Protoplanets and circumplanetary disks are elusive yet they are cornerstones to the most popular interpretations for observed protoplanetary disk structures. The gaseous velocity field also bears the imprint of planet–disk interactions, with non-Keplerian fine structure in the molecular-line channel maps (e.g., wiggles or kinks). Such features could in principle be connected to the perturber by comparison with hydrodynamical simulations, however, there is a more direct way of pinpointing the protoplanet’s location: identifying the place where the non-Keplerian velocities undergo an abrupt sign reversal, a.k.a. a "Doppler flip", in velocity centroid maps. In this talk, I will discuss the kinematic signatures of planet formation and present recent observations of the young disk in HD 100546 in CO emission and dust continuum. The high-resolution 1.3 mm continuum observation reveals fine radial and azimuthal substructures in the form of a complex maze of ridges and trenches sculpting a dust ring. Near these dust structures, we pick up a conspicuous Doppler flip. The 12CO channel maps are modulated by wiggles that deviate from Keplerian kinematics and which are somewhat connected to the Doppler flip signal.