Resolve the origin of the outer-disc kink-like feature

Determine whether the kink-like feature between approximately 125 and 171 au in the J16120 gas disc is caused by a gas gap, projected emission from the front and back disc surfaces, or an embedded outer planet.

Background

The outer-disc feature appears in both CO isotopologues and was initially considered a possible signature of a second planet. However, its large azimuthal and velocity extent, lack of a clear corresponding gap in integrated emission, and reproduction by a Keplerian model that includes front- and backside projection effects make its physical origin ambiguous. The paper concludes that the gas-gap interpretation is inconclusive and that a planetary origin is not established.