Luminous and Obscured Quasars and Their Host Galaxies
Journal article, 2018

The most heavily-obscured, luminous quasars might represent a specific phase of the evolution of the actively accreting supermassive black holes and their host galaxies, possibly related to mergers. We investigated a sample of the most luminous quasars at z approximate to 1 - 3 in the GOODS fields, selected in the mid-infrared band through detailed spectral energy distribution (SED) decomposition. The vast majority of these quasars (-80%) are obscured in the X-ray band and 30% of them to such an extent, that they are undetected in some of the deepest (2 and 4 Ms) Chandra X-ray data. Although no clear relation is found between the star-formation rate of the host galaxies and the X-ray obscuration, we find a higher incidence of heavily-obscured quasars in disturbed/merging galaxies compared to the unobscured ones, thus possibly representing an earlier stage of evolution, after which the system is relaxing and becoming unobscured.

quasars: supermassive black holes

galaxies: star formation

infrared: galaxies

X-rays: galaxies

galaxies: active

quasars: general


Agnese Del Moro

Max Planck Society

David M. Alexander

Durham University

Franz E. Bauer


Pontificia Universidad Catolica de Chile

Space Science Institute

Millennium Institute of Astrophysics

Emanuele Daddi

Paris Diderot University

Dale D. Kocevski

University of Kentucky

Flora Stanley

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Extragalactic Astrophysics

Daniel H. McIntosh

University of Missouri

Frontiers in Astronomy and Space Sciences

2296-987X (ISSN)

Vol. 4

Subject Categories

Inorganic Chemistry

Astronomy, Astrophysics and Cosmology

Condensed Matter Physics



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