Systematic Collapse of the Accretion Disc Across the Supermassive Black Hole Population

Understand

The structure of the accretion flow onto supermassive black holes (SMBH) is not well understood.

• Standard disc models match to zeroth order in predicting substantial energy dissipation within optically-thick material producing a characteristic strong blue/UV continuum.
• However they fail at reproducing more detailed comparisons to the observed spectral shapes along with their observed variability.
• Based on stellar mass black holes within our galaxy, accretion discs should undergo a transition into an X-ray hot, radiatively inefficient flow, below a (mass scaled) luminosity of $\sim 0.02\,L_{\rm{Edd}}$.