Probing the planet formation at the innermost region of disks

Takahiro Ueda, Mario Flock, Karine Perraut, Roy van Boekel, Marten Scheuck, Ondřej Chrenko, Myriam Benisty

Innermost region of disks is thought to be a birth place of close-in exoplanets which are known to be common around Sun-like stars. Particularly, the so-called dead-zone inner edge is one of the most preferential sites of rocky planets. We investigate the observability of the dead-zone inner edge with Very Large Telescope Interferometer (VLTI). We compute the radiation hydrostatic solution of the innermost region of disks with taking the silicate dust sublimation and stellar irradiation into account. The obtained physical models are used to generate synthetic images and visibilities with RADMC3D. We find that the dead-zone inner edge enhances the infrared emission of disks and the width of the rim gets broader because puffed-up disk surface induced by the dead-zone inner edge efficiently receives stellar irradiation. The model visibilities at K and N bands have a significant difference between models with and without the dead-zone inner edge. The obtained K and N band emission radii within which the half of the total emission comes from are compared with the observed values. We find that our model emission radius at K band is consistent with the observations, while the observed N-band emission radii are systematically larger than our model predictions. This suggests that the observed innermost regions of disks may have substructures such as gaps and cavities which are potentially created by close-in planets The model without the dead-zone inner edge is more consistent with the observations than the model with the dead-zone inner edge, although the observed data has large scatter in the emission radius. Future dedicated observations at K and N band will identify if the dead-zone inner edge is present or not.