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

TL;DR

This study presents kinematic and thermal evidence from ALMA observations indicating a warm, embedded giant planet candidate in the Elias 2-24 disc, characterized by perturbed gas motion and local heating effects.

Contribution

It provides the first combined kinematic and thermal signatures supporting the presence of a protoplanet in Elias 2-24, using high-resolution ALMA data.

Findings

Disc kinematics are perturbed at the candidate's location.

Local heating of CO emission suggests a warm, embedded planet.

Possible planet mass ranges from 2 to over 5 Jupiter masses.

Abstract

We report kinematic and thermal signatures associated with the directly imaged protoplanet candidate in the Elias 2-24 disc. Using the DSHARP ALMA observations of the $^{12}$CO 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 show this could either be a $\gtrsim 5$M$_\mathrm{Jup}$, or a lower mass ( $\gtrsim 2$M$_\mathrm{Jup}$) but accreting proto-planet.