  The local structure of half conformally flat gradient Ricci almost solitons
is investigated, showing that they are locally conformally flat in a
neighborhood of any point where the gradient of the potential function is
non-null. In opposition, if the gradient of the potential function is null,
then the soliton is a steady traceless $\kappa$-Einstein soliton and is
realized on the cotangent bundle of an affine surface.

Differential Geometry