Abstract
Detection of forming planets means detection of the circumplanetary disc (CPD) in reality, since the planet is still surrounded by a disc at this evolutionary stage. Yet, no comprehensive CPD modelling was done in near-infrared (near-IR) wavelengths, where high contrast imaging is a powerful tool to detect these objects. We combined 3D radiative hydrodynamic simulations of various embedded planets with radmc-3d radiative transfer post-processing that includes scattering of photons on dust particles. We made synthetic images for Very Large Telescope NaCo/ERIS in the Ks, L′, and M′ bands as well as examined the spectral energy distributions (SEDs) of discs between 1 μm and 10 cm. We found that the observed magnitudes from the planet’s vicinity will mostly depend on the CPD parameters, not on the planet’s. The CPD is 20–100x brighter than the embedded planet in near-IR. We also show how the CPD parameters, e.g. the dust-to-gas ratio will affect the resulting CPD magnitudes. According to the SEDs, the best contrast ratio between the CPD and circumstellar discs is in sub-mm/radio wavelengths and between 8–33 μm in case if the planet opened a resolvable, deep gap (≥5MJup), while the contrast is particularly poor in the near-IR. Hence, to detect the forming planet and its CPD, the best chance today is targeting the sub-mm/radio wavelengths and the 10-μm silicate feature vicinity. In order to estimate the forming planet’s mass from the observed brightness, it is necessary to run system specific disc modelling.
Szulágyi, J