PICONCELLI, EnricoEnricoPICONCELLIVignali, C.C.VignaliBianchi, S.S.BianchiZAPPACOSTA, LucaLucaZAPPACOSTAFritz, J.J.FritzLANZUISI, GiorgioGiorgioLANZUISIMiniutti, G.G.MiniuttiBONGIORNO, ANGELAANGELABONGIORNOFeruglio, C.C.FeruglioFIORE, FabrizioFabrizioFIOREMaiolino, R.R.Maiolino2020-12-172020-12-1720150004-6361http://hdl.handle.net/20.500.12386/28953We thank the anonymous referee for helpful comments. E.P. and A.B. acknowledge financial support from INAF under the contract PRIN-INAF-2012.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<SUP>47</SUP> erg s<SUP>-1</SUP>), 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 (Γ ~ 0.8) as typically seen in heavily obscured AGN. This, along with the presence of strong Fe Kα emission, clearly suggests a reflection-dominated spectrum due to Compton-thick absorption. In this scenario, the observed luminosity of L<SUB>2-10</SUB>~ 2 × 10<SUP>44</SUP> erg s<SUP>-1</SUP> is a fraction (<10%) of the intrinsic one, which is estimated to be ≳ 5 × 10<SUP>45</SUP> erg s<SUP>-1</SUP> 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 M<SUB>☉</SUB> yr<SUP>-1</SUP>). 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.STAMPAenArticle10.1051/0004-6361/2014253242-s2.0-84922458042000349467000157https://www.aanda.org/articles/aa/abs/2015/02/aa25324-14/aa25324-14.html2015A&A...574L...9PFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation