Quasars: What turns them off?

Abstract

(Abridged) We explore the idea that the anti-hierarchical turn-off observed in the quasar population arises from self-regulating feedback, via an outflow mechanism. Using a detailed hydrodynamic simulation we calculate the luminosity function of quasars down to a redshift of z=1 in a large, cosmologically representative volume. Outflows are included explicitly by tracking halo mergers and driving shocks into the surrounding intergalactic medium. Our results are in excellent agreement with measurements of the spatial distribution of quasars, and we detect an intriguing excess of galaxy-quasar pairs at very short separations. We also reproduce the anti-hierarchical turnoff in the quasar luminosity function, however, the magnitude of the turn-off falls short of that observed as well as that predicted by analogous semi-analytic models. The difference can be traced to the treatment of gas heating within galaxies. The simulated galaxy cluster L_X-T relationship is close to that observed for z~1 clusters, but the simulated galaxy groups at z=1 are significantly perturbed by quasar outflows, suggesting that measurements of X-ray emission in high-redshift groups could well be a "smoking gun" for the AGN heating hypothesis.

16 pages, 11 figures, submitted to ApJ, comments welcomed

References in corpus (3)

• The Gemini Deep Deep Survey: III. The abundance of massive galaxies 3-6 billion years after the Big Bang
• Definitive Identification of the Transition between Small- to Large-Scale Clustering for Lyman Break Galaxies
• The Small-Scale Environment of Quasars

Cited by in corpus (14)

• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• A unified model for AGN feedback in cosmological simulations of structure formation
• Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4
• Direct cosmological simulations of the growth of black holes and galaxies
• The Discovery of 1000 km/s Outflows in Massive Post-starburst Galaxies at z=0.6
• The Self-Regulated Growth of Supermassive Black Holes
• Simulating Subhalos at High Redshift: Merger Rates, Counts, and Types
• Dynamics of Rotating Accretion Flows Irradiated by a Quasar
• Measuring AGN Feedback with the Sunyaev-Zel'dovich Effect
• Effects of Quasar Feedback in Galaxy Groups
• The Clustering and Host Halos of Galaxy Mergers at High Redshift
• Three-Dimensional Simulations of Inflows Irradiated by a Precessing Accretion Disk in Active Galactic Nuclei: Formation of Outflows
• Anisotropic AGN Outflows and Enrichment of the Intergalactic Medium
• Simulations of the Sunyaev-Zeldovich Effect from Quasars