The host galaxies of luminous quasars

摘要: We present the results of a deep Hubble Space Telescope (HST)/Wide Field and Planetary Camera 2 imaging study 17 quasars at z ≃ 0.4, designed to determine properties their host galaxies. The sample consists with absolute magnitudes in range -24 ≥ M V - 28, allowing us investigate galaxy across decade quasar luminosity, but single redshift. Our previous studies active galactic nuclei hosts have focused primarily on moderate most powerful objects current powers comparable luminous found high redshifts. find that galaxies all radio-loud quasars, radio-quiet our nuclear luminosities < -24, are massive bulge-dominated galaxies, confirming extending trends deduced from studies. From best-fitting model we estimated spheroid hence black hole (BH) masses, efficiency (with respect Eddington luminosity) which each emits radiation. largest inferred mass is BH 3 x 10 9 ○. , holes centres M87 Cygnus A. no evidence for super-Eddington accretion rates even (0.05 L/L Edd 1.0). role scatter hole-spheroid relation determining ratio host-galaxy by generating simulated populations lying Schechter function. Within subsample highest-luminosity observed variation nuclear-host luminosity consistent being result relation. Quasars ratios can be explained terms sub-Eddington high-mass tail imply that, owing function cut-off, should not continue increase linearly very highest luminosities. Any more than = -27 elliptical hosts, day would -24.5.