A POPULATION OF DUST-RICH QUASARS AT z ∼ 1.5

We report Herschel SPIRE (250, 350, and 500 mu m) 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 mu m 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 10(11.3) to 10(13.5) L-circle dot, 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 similar to 1 mm. However, their FIR properties cannot be predicted from shorter wavelengths (0.3-20 mu m, rest frame), and the bolometric luminosities derived using the 5100 angstrom 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.