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arXiv · 1412.3595

The hidden quasar nucleus of a WISE-selected, hyperluminous, dust-obscured galaxy at z ~ 2.3

E. Piconcelli·C. Vignali·S. Bianchi·L. Zappacosta·J. Fritz·G. Lanzuisi·G. Miniutti·A. Bongiorno·C. Feruglio·F. Fiore·R. Maiolino
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Abstract

We present the first X-ray spectrum of a Hot dust-obscured galaxy (DOG), namely W1835+4355 at z ~ 2.3. Hot DOGs represent a very rare population of hyperluminous (>= 10^47 erg/s), dust-enshrouded objects at z > 2 recently discovered in the WISE All Sky Survey. The 40 ks XMM-Newton spectrum reveals a continuum as flat (Gamma ~ 0.8) as typically seen in heavily obscured AGN. This, along with the presence of strong Fe Kalpha emission, clearly suggests a reflection-dominated spectrum due to Compton-thick absorption. In this scenario, the observed luminosity of L(2-10 keV) ~ 2 x 10^44 erg/s is a fraction (<10%) of the intrinsic one, which is estimated to be >~ 5 x 10^45 erg/s by using several proxies. The Herschel data allow us to constrain the SED up to the sub-mm band, providing a reliable estimate of the quasar contribution (~ 75%) to the IR luminosity as well as the amount of star formation (~ 2100 Msun/yr). Our results thus provide additional pieces of evidence that associate Hot DOGs with an exceptionally dusty phase during which luminous quasars and massive galaxies co-evolve and a very efficient and powerful AGN-driven feedback mechanism is predicted by models.

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E. Piconcelli, C. Vignali, S. Bianchi, L. Zappacosta, J. Fritz, G. Lanzuisi, G. Miniutti, A. Bongiorno, C. Feruglio, F. Fiore, R. Maiolino. 2014-12-11. The hidden quasar nucleus of a WISE-selected, hyperluminous, dust-obscured galaxy at z ~ 2.3. https://doi.org/10.1051/0004-6361%2F201425324

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