Observing Ionized Nebulae around Quasars with JWST
Our recent JWST Cycle 2 GO proposal aims to shed new light on the formation and growth of supermassive black holes in the early universe. Our standard black hole growth model requires very long timescales for the black hole growth of billions of years. However, we have recently shown that new estimates of the quasars' lifetimes - the times that galaxies shine as luminous quasars and during which the bulk of the black hole growth is believed to occur - indicate much shorter lifetimes of only a million years. Such short lifetimes and the rapid concurrent black hole growth can be explained by invoking either highly radiatively inefficient ``super-Eddington’’ accretion rates, or obscured, dust-enshrouded black hole growth phases. In order to break this degeneracy, our proposal aims to spatially map the ionizing imprint of the quasars’ emission on the surrounding circumgalactic gas, in order to provide a model-independent lifetime estimate perpendicular to our sightline to the quasar, based on the light travel time of the quasar’s radiation.
Our recent JWST Cycle 2 GO proposal aims to shed new light on the formation and growth of supermassive black holes in the early universe. Our standard black hole growth model requires very long timescales for the black hole growth of billions of years. However, we have recently shown that new estimates of the quasars' lifetimes - the times that galaxies shine as luminous quasars and during which the bulk of the black hole growth is believed to occur - indicate much shorter lifetimes of only a million years. Such short lifetimes and the rapid concurrent black hole growth can be explained by invoking either highly radiatively inefficient ``super-Eddington’’ accretion rates, or obscured, dust-enshrouded black hole growth phases. In order to break this degeneracy, our proposal aims to spatially map the ionizing imprint of the quasars’ emission on the surrounding circumgalactic gas, in order to provide a model-independent lifetime estimate perpendicular to our sightline to the quasar, based on the light travel time of the quasar’s radiation.