Abstract

Invited Talk - Splinter SMBHs

Wednesday, 09 September 2026, 16:44   (MW-0250)

The power of SDSS-V & 4MOST: a new era of spectroscopic AGN surveys

A. Merloni
MPE

We live in the era of large multi-wawelength astronomical surveys. The rich statistical samples of AGN they can deliver, with well defined selection functions, can be and are being used to reveal how accretion into Super Massive Black Holes (SMBH) and jet acceleration are connected with the evolving galaxy population. In Summer 2026 the 2nd release of eROSITA-DE and the 20th release of SDSS-V data will unveil new AGN catalogs containing more than a quarter million spectra of X-ray selected AGN and tens of thousands of spectra of radio selected AGN from ASKAP/RACS survey, the largest spectroscopic samples of X-ray and radio-selected AGN to date. Around the same time, the 4MOST survey will start operations. In 5 years, 4MOST will cover almost the entire southern hemisphere and will deliver statistical samples of about 3.5 Million AGN, selected via X-rays (eROSITA), MIR (WISE), optical astrometry (Gaia) and variability (ZTF, LSST). I will describe these surveys, their design, implementation, and the resulting AGN samples, and provide some examples of how we can use these unique datasets to address long-standing questions about the connection between accretion states, jet launching and evolutionary paths in SMBH growth.