Speaker: Johannes Buchner (MPE)

Date: Wednesday 13 September 2023

Time: 14:00

Location: Physics 3.21 (Berry)

Super-massive black holes across cosmic time

Black holes of millions to billion solar masses in the centres of nearby galaxies raise the question how and when these black holes were created. I will give an overview of some investigations of the origin, growth and consequences of the presence of such black holes studied with X-ray surveys including from the new all-sky surveyor eROSITA and multi-wavelength information. In understanding the host galaxies growing their black holes, a on-going challenge is that light from Active Galactic Nuclei contaminates the emission of galaxies, making the measurement of stellar masses and star-formation rates notoriously unreliable. Overly high masses when the AGN model is incomplete are typical. This prevents evolutionary tests comparing black hole and host galaxy properties. Our group developed a novel data-driven benchmark data set where host galaxy masses and AGN properties are known, and tested a variety of SED fitting codes to critically evaluate their ability to infer host galaxy properties. Finally, we present an unbiased SED fitting method, GRAHSP, Grasping Reliably the AGN Host Stellar Population, to test the evolution of supermassive black holes in the centres of galaxies.