A Population of Dust-rich Quasars at z ~ 1.5

Dai, Y. Sophia; Bergeron, Jacqueline; Elvis, Martin; Omont, Alain; Huang, Jia-Sheng; Bock, Jamie; Cooray, Asantha; Fazio, Giovanni; Hatziminaoglou, Evanthia; Ibar, Edo; Magdis, Georgios E.; Oliver, Seb J.; Page, Mathew J.; Pérez-Fournon, I.; Rigopoulou, Dimitra; Roseboom, Isaac G.; Scott, Douglas; Symeonidis, Myrto; Trichas, Markos; Vieira, Joaquin D.; Willmer, Christopher N. A.; Zemcov, Michael
Bibliographical reference

The Astrophysical Journal, Volume 753, Issue 1, article id. 33 (2012).

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7
2012
Number of authors
22
IAC number of authors
1
Citations
33
Refereed citations
30
Description
We report Herschel SPIRE (250, 350, and 500 μm) detections of 32 quasars with redshifts 0.5 <=z < 3.6 from the Herschel Multi-tiered Extragalactic Survey (HerMES). These sources are from a MIPS 24 μm flux-limited sample of 326 quasars in the Lockman Hole Field. The extensive multi-wavelength data available in the field permit construction of the rest-frame spectral energy distributions (SEDs) from ultraviolet to the mid-infrared for all sources, and to the far-infrared (FIR) for the 32 objects. Most quasars with Herschel FIR detections show dust temperatures in the range of 25-60 K, with a mean of 34 K. The FIR luminosities range from 1011.3 to 1013.5 L &sun;, qualifying most of their hosts as ultra- or hyper-luminous infrared galaxies. These FIR-detected quasars may represent a dust-rich population, but with lower redshifts and fainter luminosities than quasars observed at ~1 mm. However, their FIR properties cannot be predicted from shorter wavelengths (0.3-20 μm, rest frame), and the bolometric luminosities derived using the 5100 Å index may be underestimated for these FIR-detected quasars. Regardless of redshift, we observed a decline in the relative strength of FIR luminosities for quasars with higher near-infrared luminosities.
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Formation and Evolution of Galaxies: Observations in Infrared and other Wavelengths
This IAC research group carries out several extragalactic projects in different spectral ranges, using space as well as ground-based telescopes, to study the cosmological evolution of galaxies and the origin of nuclear activity in active galaxies. The group is a member of the international consortium which built the SPIRE instrument for the
Ismael
Pérez Fournon