Kinematic and thermal signatures of the directly imaged protoplanet candidate around Elias 2-24

Abstract

We report kinematic and thermal signatures associated with the directly imaged protoplanet candidate in the Elias 2-24 disc. Using the DSHARP (Disc Substructures at High Angular Resolution Project) ALMA (Atacama Large Millimetre/submillimetre Array) observations of the 12CO J = 2 - 1 line, we show that the disc kinematics are perturbed, with a detached CO emission spot at the location of the planet candidate and traces of spiral wakes, and also that the observed CO emission intensities require local heating. While the foreground extinction hides the velocity channels associated with the planet, preventing a planet mass estimate, the level of gas heating implied by the CO emission indicates the presence of a warm, embedded giant planet. Comparison with models shows that this could either be a ≳5 MJup or a lower mass (≳2 MJup) but accreting protoplanet.