Credit: NASA, ESA, S. Baum and C. O’Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA)
The SKA will survey large volumes of the Universe, enabling direct studies of how cosmic structures have evolved over time. Of particular interest are questions of how supermassive black holes have grown through accretion and how the intense radiation generated by that accretion has impacted the galaxies, which host them.
The SKA data enable these studies, but scientific interpretation of the SKA data will rely on the availability of complementary, multi-wavelength datasets. These include deep imaging of the Universe in many other bands, ranging from mm-wave to optical to X-ray. Optical imaging surveys give us the information we need to identify the host galaxies and to measure their distances from Earth. MM-wave and X-ray data will help us diagnose the nature of the accretion onto the black holes, allowing us to understand the impacts of extremely high accretion and more mild accretion and the relative frequency and the environmental impacts of both.
Our German SKA collaboration is centrally involved in these complementary surveys, and so we are well positioned to play leading roles in these SKA driven scientific discoveries. The German involvement in the DLR supported Euclid optical and NIR imaging mission and the eROSITA X-ray mission couple to our involvement in the South Pole Telescope, the Dark Energy Survey and the Rubin Observatory. Together with SKA these surveys provide a rich fabric of multi-wavelength cosmic observations that will feed scientific discoveries for decades to come.