The perturbed sublimation rim of the dust disk around the post-AGB binary IRAS08544-4431

Context. Post-asymptotic giant branch (post-AGB) binaries are surrounded by stable dusty and gaseous disks similar to the ones around young stellar objects. Whereas, significant effort has been spent on modeling observations of disks around young stellar objects, the disks around post-AGB binaries have received significantly less attention, even though they pose significant constraints on theories of disk physics and binary evolution.
Context. Post-asymptotic giant branch (post-AGB) binaries are surrounded by stable dusty and gaseous disks similar to the ones around young stellar objects. Whereas, significant effort has been spent on modeling observations of disks around young stellar objects, the disks around post-AGB binaries have received significantly less attention, even though they pose significant constraints on theories of disk physics and binary evolution.
Context. Post-asymptotic giant branch (post-AGB) binaries are surrounded by stable dusty and gaseous disks similar to the ones around young stellar objects. Whereas, significant effort has been spent on modeling observations of disks around young stellar objects, the disks around post-AGB binaries have received significantly less attention, even though they pose significant constraints on theories of disk physics and binary evolution.
Results. The best-fit radiative transfer model shows excellent agreement with the spectral energy distribution up to millimeter wavelengths as well as with the PIONIER visibility data. It requires a rounded inner rim structure, starting at a radius of 8.25 au. However, the model does not fully reproduce the detected over-resolved flux nor the azimuthal flux distribution of the inner rim. While the asymmetric inner disk rim structure is likely to be the consequence of disk-binary interactions, the origin of the additional over-resolved flux remains unclear.
Conclusions. As in young stellar objects, the disk inner rim of IRAS08544-4431 is ruled by dust sublimation physics. Additional observations are needed to understand the origin of the extended flux and the azimuthal perturbation at the inner rim of the disk.