Outflows and disks in post-RGB objects — products of common envelope ejection?

Interacting binaries within a common envelope, wherein the primary is a red giant are believed to result in a recently identified evolutionary class - the dusty post-RGB stars. Our SED modeling of eight post-RGBs in the LMC indicates the presence of geometrically thick disks with substantial opening angle in addition to the outer shells. We estimated the total dust mass (and gas mass assuming gas-to-dust ratio) in the disks and shells and set constraints on the dust grain compositions and sizes. The only known Galactic object of this class is the Boomerang nebula. Additionally, we present a DUSTY model of the Boomerang that can serve as a template for 2D modeling of the object using RADMC-3D. 2D modeling is essential to dissect the morphology of the spatially-unresolved post-RGBs in the LMC. These models may then be tested with future HST and ALMA imaging, together with JWST spectroscopy of these objects.