A Sensitive X-ray Survey of the LSST Deep-Drilling Fields: Complete XMM-Newton Results and Ongoing Science Investigations

Cosmic X-ray surveys over the past two decades have played a critical role in transforming our understanding of growing supermassive black holes (SMBHs) in the distant universe. I will describe one key survey, recently completed, advancing this effort: the 13.1 deg² XMM-SERVS survey. XMM-SERVS has successfully used XMM-Newton to map three legacy sky fields at 50 ks depth: the SERVS areas of CDF-S, XMM-LSS, and ELAIS-S1. These fields have first-rate multiwavelength coverage already and are LSST/DES Deep-Drilling Fields, MOONS/PFS massive spectroscopy fields, prime TolTEC/ALMA fields, and multi-object reverberation-mapping fields. About 12,000 X-ray sources have been detected, the majority of which (86%) are active galactic nuclei (AGNs), and these are presently being characterized and studied. I will also briefly summarize ongoing science investigations in these fields, including multiwavelength fitting of infrared-to-X-ray spectral energy distributions, identification of the most highly X-ray obscured AGNs, and combined radio/X-ray AGN investigations.