High-priority Compact-object Candidates in Young Clusters from the Gaia DR3 Non-Single-Star Catalog

The search for massive compact objects such as black holes (BHs) or neutron stars (NSs) in star clusters is a longstanding challenge in astrophysics, yet no definitive identification of such compact objects in young clusters has been reported. In this Letter, we construct a sample of high-priority candidates for follow-up investigation. By cross-matching the cluster catalog with the Gaia Non-Single-Star database and estimating companion masses, we identify 13 systems with companion masses exceeding 1.4 M ⊙ , 3 of which have masses above 2.1 M ⊙ . Applying our newly developed Astrometric Mass-Ratio Function (AMRF) classification based on cluster-specific isochrones, we identify three systems whose companions cannot readily be explained by a single main-sequence star or an unresolved close binary. These systems have inferred companion masses exceeding 2.1 M ⊙ , suggesting that they may be high-mass compact-object candidates. Joint Gaia and radial velocity orbit fitting for a comparison subset yields companion masses broadly consistent with the astrometric estimates, supporting the use of our framework for target prioritization. These unconfirmed systems are valuable targets for multiepoch spectroscopy, high-resolution imaging, and future Gaia epoch astrometry.