Issue |
A&A
Volume 574, February 2015
|
|
---|---|---|
Article Number | L9 | |
Number of page(s) | 4 | |
Section | Letters | |
DOI | https://doi.org/10.1051/0004-6361/201425324 | |
Published online | 05 February 2015 |
The hidden quasar nucleus of a WISE-selected, hyperluminous, dust-obscured galaxy at z ~ 2.3
1
Osservatorio Astronomico di Roma (INAF),
via Frascati 33, 00040
Monte Porzio Catone ( Roma),
Italy
e-mail:
piconcelli@mporzio.astro.it
2
Dipartimento di Fisica e Astronomia, Università di
Bologna, Viale Berti Pichat
6/2, 40127
Bologna,
Italy
3
Osservatorio Astronomico di Bologna (INAF), via Ranzani
1, 40127
Bologna,
Italy
4
Dipartimento di Matematica e Fisica, Università degli Studi Roma
Tre, via della Vasca Navale
84, 00146
Roma,
Italy
5
Sterrenkundig Observatorium Universiteit Gent,
Krijgslaan 281, S9,
9000
Gent,
Belgium
6
Centro de Astrobiologia (CSIC-INTA), Dep. de Astrofísica, ESAC, PO
Box 78, 28691 Villanueva de la Cañada, Madrid, Spain
7
Institute de Radioastronomie Millimétrique,
300 rue de la Piscine, 38406 St. Martin
d’Hères, Grenoble,
France
8
Cavendish Laboratory, University of Cambridge,
19 J. J. Thomson Avenue,
Cambridge
CB3 0HE,
UK
Received: 12 November 2014
Accepted: 5 December 2014
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 (≥1047 erg s-1), 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 L2−10~ 2 × 1044 erg s-1 is a fraction (<10%) of the intrinsic one, which is estimated to be ≳ 5 × 1045 erg s-1 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⊙ yr-1). 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.
Key words: galaxies: individual: WISE J183533.71+435549.1 / galaxies: active / galaxies: nuclei / submillimeter: galaxies / X-rays: galaxies
© ESO, 2015
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