A census of compact objects in Gaia DR3

Most known stellar black holes are members of close binaries, where accretion-fueled X-ray emission was able to trigger their detection. However, if the separation between the two components is sufficiently large, the accretion rate drops, leaving the black hole in quiescence. Presumably, most black holes in binaries reside in this dormant state, waiting to be discovered. A promising detection channel for these systems is the astrometric wobble induced on the luminous star by its dark companion. In preparation for the release of astrometric orbits of Gaia DR3, Shahaf, Mazeh, Faigler, and Holl (2019) proposed a triage technique to identify hierarchical triples and astrometric binaries with compact companions. Having the astrometric orbits of Gaia at hand, we applied this technique to identify a large sample of hierarchical triples, hundreds of stars with a white dwarf companion, and dozens of systems with neutron stars or black-hole candidates as their faint massive secondaries. In this talk, I will describe the triage classification scheme, present the population of compact objects found in Gaia DR3, and discuss some prospects for future study.