TRINITY – III. Quasar luminosity functions decomposed by halo, galaxy, and black hole masses as well as Eddington ratios from z = 0–10

We present the redshift evolution of quasar luminosity functions (QLFs) decomposed by halo mass, galaxy mass, supermassive black hole (SMBH) mass, and Eddington ratio, as well as SMBH/radiative energy output ratios from TRINITY, a flexible empirical model that self-consistently infers the halo–galaxy–SMBH connection that match observational data. Key findings include: (1) The normalization of quasar luminosity function increases by ∼3–4 dex from z ∼ 10 to z ∼ 4, due to the fast mass build-up of different SMBH populations; (2) From z ∼ 4 to z ∼ 1, less massive galaxies and SMBHs make up bigger and bigger fractions of QLFs, due to the active galactic nuclei (AGNs) downsizing effect; (3) At z ∼ 0, massive haloes/galaxies/SMBHs are responsible for most bright quasars due to low Eddington ratios among all SMBHs; (4) The bright ends of QLFs are dominated by SMBHs that are at least 0.3 dex overmassive relative to the median SMBH mass–galaxy mass relation; (5) QLFs at z ∼ 6–7 are dominated by SMBHs accreting at Eddington ratios 0.1 < η_rad < 1, but super-Eddington AGNs contribute more significantly to QLFs towards z ∼ 9–10.