Speaker
Description
Light from Active Galactic Nuclei contaminates the Spectral Energy Distribution (SED) 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 and is difficult to solve, because we lack independent access to a ground truth stellar mass. We present a novel benchmark data set where host galaxy masses and AGN properties are known. This is a data driven approach blending the light of pure galaxies with that of quasars without assuming a true model of the AGN. We test a variety of SED fitting codes and critically evaluate their ability to infer stellar mass. Finally, we present an unbiased SED fitting method, GRAHSP, Grasping Reliably the AGN Host Stellar Population, and its application to the eROSITA surveys.
