Submillimeter emission associated with candidate protoplanets

Abstract

We present the discovery of a spatially unresolved source of sub-millimeter continuum emission ($\lambda=855$ $\mu$m) associated with a young planet, PDS 70 c, recently detected in H$\alpha$ emission around the 5 Myr old T Tauri star PDS 70. We interpret the emission as originating from a dusty circumplanetary disk with a dust mass between $2\times10^{-3}$ and $4.2 \times 10^{-3}$ Earth masses. Assuming a standard gas-to-dust ratio of 100, the ratio between the total mass of the circumplanetary disk and the mass of the central planet would be between $10^{-4}-10^{-5}$. Furthermore, we report the discovery of another compact continuum source located $0.074''\pm0.013''$ South-West of a second known planet in this system, PDS 70 b, that was previously detected in near-infrared images. We speculate that the latter source might trace dust orbiting in proximity of the planet, but more sensitive observations are required to unveil its nature.