A population of dust-rich quasars at z ∼ 1.5

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 d...

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Xehetasun bibliografikoak
Egile Nagusiak: Dai, Y, Bergeron, J, Elvis, M, Omont, A, Huang, J, Bock, J, Cooray, A, Fazio, G, Hatziminaoglou, E, Ibar, E, Magdis, G, Oliver, S, Page, M, Perez-Fournon, I, Rigopoulou, D, Roseboom, I, Scott, D, Symeonidis, M, Trichas, M, Vieira, J, Willmer, C, Zemcov, M
Formatua: Journal article
Hizkuntza:English
Argitaratua: Institute of Physics Publishing 2012
Deskribapena
Gaia: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 25-60K, with a mean of 34K. The FIR luminosities range from 1011.3 to 1013.5 L, 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 1mm. However, their FIR properties cannot be predicted from shorter wavelengths (0.3-20 μm, rest frame), and the bolometric luminosities derived using the 5100Å 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. © 2012. The American Astronomical Society. All rights reserved.