AUTHOR=Del Moro Agnese , Alexander David M. , Bauer Franz E. , Daddi Emanuele , Kocevski Dale D. , Stanley Flora , McIntosh Daniel H. TITLE=Luminous and Obscured Quasars and Their Host Galaxies JOURNAL=Frontiers in Astronomy and Space Sciences VOLUME=4 YEAR=2018 URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2017.00067 DOI=10.3389/fspas.2017.00067 ISSN=2296-987X ABSTRACT=

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 ≈ 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.