Hunting for young planets at the inner rim of protoplanetary disks

The inner rim of protoplanetary disks plays an important role for planet formation (because it can trap migrating planets or enable their in situ formation) as well as for disk observations (because it strongly reprocesses the irradiation of the central star). We use a radiative hydrostatic model to compute the structure of the inner rim and we study its changes due to an embedded gap-opening planet. Based on the resulting dust distributions, we calculate synthetic images of the inner rim with a planet-induced gap by performing Monte-Carlo radiative transfer simulations. Our reference model is based on parameters of the HD 163296 disk but we extend our study to T Tauri stars as well. Our preliminary results are the following: (i) since the aspect ratio at the inner rim is relatively low (h ~ 0.02-0.03), so is the minimum gap-opening planet mass (planets that are a few tens of Earth masses can open shallow gaps in our simulations); (ii) the rim with a gap exhibits two emission rings in our synthetic images, whereas there is only one wide ring when the rim is unperturbed. We look for characteristic signatures of the double-ringed structure in the near-infrared interferometric observables and we discuss prospects of their detection with the Very Large Telescope Interferometer. If successful, our study could open new pathways to detecting traces of planet formation at sub-au central regions of protoplanetary disks.