The MAVERIC survey: identifying exotic accreting systems in Galactic globular clusters, hundreds at a time

Accreting neutron stars and cataclysmic variables in globular clusters overwhelmingly outnumber similar systems in the rest of the Galaxy. This overabundance - which is attributed to the formation of these systems through stellar encounters in these dense clusters - is a challenge and an opportunity. It is a challenge as to why are there so few accreting black holes are found while thousands of them are expected to have formed in these clusters, indicating that a deep search for these systems is needed to shed light on their population and the impact of cluster evolution. Simultaneously, the overabundance is an opportunity, as these clusters provide a rich sample of thousands of accreting systems with rather well-established distance measurements (as the distance to clusters is better constrained than many other astronomical objects), allowing deep studies of accretion in a large sample of well-observed systems. We have recently finished a deep radio/X-ray survey of 50 Galactic globular clusters (with targeted follow ups in optical and infrared), to search for stellar- and intermediate- mass black holes in these clusters, and to identify and study other exotic systems (like ultracompact X-ray binaries). This survey has resulted in extensive catalogs of more than 1000 X-ray sources and 2000 radio sources detected towards these clusters. In this talk, I will summarize these catalogs, their implication on our understanding of globular cluster evolution, and highlight some of the recent results from our survey; namely, new stringent upper limits on the presence of intermediate mass black holes in globular clusters, and the discovery of several accreting black hole candidates in various binary configurations.