The Luminosity Function of high-redshift QSOs - A combined analysis of GOODS and SDSS

Abstract

Aims: In this work the luminosity function of QSOs is measured in the redshift range 3.5<z<5.2 for the absolute magnitude interval -21<M_{145}<-28. The determination of the faint end of the luminosity function at these redshifts provides important constraints on models of joint evolution of galaxies and AGNs. Methods: We have defined suitable criteria to select faint QSOs in the GOODS fields, checking in detail their effectiveness and completeness. Spectroscopic follow-up of the resulting QSO candidates has been carried out. The confirmed sample of faint QSOs is compared with a brighter one derived from the SDSS. We have used a Monte-Carlo technique to estimate the properties of the luminosity function, checking various parameterizations for its shape and evolution. Results: Models based on Pure Density Evolution show better agreement with observation than models based on Pure Luminosity Evolution. However a different break magnitude with respect to z~2.1 is required at 3.5<z<5.2. Models with a steeper faint end score a higher probability. We do not find any evidence for a flattening of the bright end at redshift z>3.5. Conclusions: The estimated space density evolution of QSOs indicates a suppression of the formation and/or feeding of Supermassive Black Holes at these redshifts. The QSO contribution to the UV background is insufficient to ionize the IGM at 3.5<z<5.2.

17 pages, 13 ps figures, A&A accepted. Updated to journal version

References in corpus (1)

• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges

Cited by in corpus (34)

• A New Calculation of the Ionizing Background Spectrum and the Effects of HeII Reionization
• Cosmic X-ray Surveys of Distant Active Galaxies: The Demographics, Physics, and Ecology of Growing Supermassive Black Holes
• The Bolometric Quasar Luminosity Function at z = 0-7
• A Survey of z~6 Quasars in the SDSS Deep Stripe: I. a Flux-Limited Sample at z_{AB}<21
• Quasars Are Not Light-Bulbs: Testing Models of Quasar Lifetimes with the Observed Eddington Ratio Distribution
• New Constraints on the Lyman Continuum Escape Fraction at z~1.3
• The Far-Ultraviolet Continuum Slope as a Lyman Continuum Escape Estimator at High-redshift
• The VVDS type-1 AGN sample: The faint end of the luminosity function
• A submillimetre galaxy at z=4.76 in the LABOCA survey of the Extended Chandra Deep Field South
• Modeling the cosmological co-evolution of supermassive black holes and galaxies: I. BH scaling relations and the AGN luminosity function
• High redshift quasars in the COSMOS survey: the space density of z>3 X-ray selected QSOs
• Supermassive Black Holes in the Hierarchical Universe: A General Framework and Observational Tests
• The History and Morphology of Helium Reionization
• Triggering Active Galactic Nuclei in Hierarchical Galaxy Formation: Disk instability vs. Interactions
• Peering through the holes: the far UV color of star-forming galaxies at z~3-4 and the escaping fraction of ionizing radiation
• High-Redshift QSOs in the SWIRE Survey and the z~3 QSO Luminosity Function
• Quasar UV luminosity function evolution up to z=8
• Modelling the luminosities and sizes of radio galaxies: radio luminosity function at z = 6
• The Pan-STARRS1 $\mathbf{z}>5.6$ Quasar Survey: III. The $\mathbf{z}\approx 6$ Quasar Luminosity Function
• On the AGN nature of two UV bright sources at z_spec~5.5 in the CANDELS fields: an update of the AGN space density at M1450~-22.5
• Fluctuations in the Ionizing Background During and After Helium Reionization
• AGN-driven helium reionization and the incidence of extended HeIII regions at redshift z>3
• Anti-hierarchical evolution of the Active Galactic Nucleus space density in a hierarchical universe
• The spectroscopic follow-up of the QUBRICS bright quasar survey
• The Probabilistic Random Forest applied to the selection of quasar candidates in the QUBRICS Survey
• Quasar UV Luminosity Function at $3.5<z<5.0$ from SDSS Deep Imaging Data
• The ALPINE-ALMA [CII] survey: double stellar population and AGN activity in a galaxy at $z\sim 5.5$
• The Intrinsic Quasar Luminosity Function: Accounting for Accretion Disk Anisotropy
• On the Evolution of High-Redshift Active Galactic Nuclei
• Candidate z ~ 2.5 Lyman Continuum Sources in the GOODS Fields
• Spitzer's View of the Candidate Cluster and Protocluster Catalog (CCPC)
• Detecting quasars at very high redshift with next generation X-ray telescopes
• The optical luminosity function of LOFAR radio-selected quasars at $1.4\le z\le 5.0$ in the NDWFS-Boötes field
• EMU/GAMA: A new approach to characterising radio luminosity functions