Speakers
Description
Understanding how protoplanetary disks deplete their solid reservoirs is a central question in planet formation, since disk evolution sets the timescale over which planets can assemble. Constraining this process requires large homogeneous samples of disks with reliable stellar ages. We revisit the disk dust mass evolution in the Scorpius–Centaurus (Sco–Cen) OB association, the nearest OB association, and an ideal laboratory for studying disk evolution. Sco–Cen contains multiple coeval stellar subgroups spanning ages from newborn stars to ~20 Myr that can now be robustly identified with Gaia DR3 astrometry. We combine this Gaia-based membership and age catalogue with a homogeneous compilation of ALMA dust masses, obtaining a sample of 425 sources across 17 subgroups. We find a continuous decrease in disk dust mass with subgroup age for populations between 3 and 10 Myr. Older subgroups have insufficient ALMA coverage (<3%) to be included in the analysis. This trend is consistent with the progressive depletion of mmsized dust reservoirs reported in previous studies. The key advance of this work is that the Gaia-based census resolves multiple substructures that were previously treated as a single population, enabling a finer temporal sampling of disk evolution across the association. We also recover the known dependence of disk dust mass on stellar mass when comparing populations. These results highlight the importance of homogeneous and unbiased mm/sub-mm surveys, together with precise stellar demographics, for constraining disk dispersal and planet formation timescales in OB associations.
