Fabian Walter (MPIA Heidelberg): "Illuminating the Dark Ages: Luminous Quasars and Their Massive Host Galaxies in the Reionization Epoch"

Quasars are the brightest, non-transient objects observed at the highest redshifts, z>7, which makes them unique probes of the evolution of black holes, massive galaxies and the intergalactic medium. The density of high redshift quasars puts powerful constraints on the mechanisms that are required to seed and grow supermassive, >10^9 solar mass black holes less than a Gyr after the Big Bang. Observations in the (sub)millimeter can constrain the gas and dust content, star formation rate and masses of the galaxies hosting these luminous quasars. I will present the results of various multi-wavelength follow-up programmes of the most distant quasars currently known, focusing on our recent high-resolution ALMA observations of quasar host galaxies at z~7 and discuss the implications of the findings on massive galaxy formation, the black hole - galaxy coevolution and cosmic reionization.