Thursday, May 10, 2012

1205.1808 (Y. Sophia Dai et al.)

A Population of Dust-Rich Quasars at z ~ 1.5    [PDF]

Y. Sophia Dai, Jacqueline Bergeron, Martin Elvis, Alain Omont, Jia-Sheng Huang, Jamie Bock, Asantha Cooray, Giovanni Fazio, Evanthia Hatziminaoglou, Edo Ibar, Georgios E. Magdis, Seb J. Oliver, Mathew J. Page, Ismael Perez-Fournon, Dimitra Rigopoulou, Isaac G. Roseboom, Douglas Scott, Myrto Symeonidis, Markos Trichas, Joaquin D. Vieira, Christopher N. A. Willmer, Michael Zemcov
We report Herschel SPIRE (250, 350, and 500 micron) detections of 32 quasars with redshifts 0.5 < z < 3.6 from the Herschel Multi-tiered Extragalactic Survey. These sources are from a MIPS 24 micron 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 25K to 60K, with a mean of 34K. The FIR luminosities range from 10^{11.3} to 10^{13.5} Lsun, 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 micron, rest-frame), and the bolometric luminosities derived using the 5100 A 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.
View original: http://arxiv.org/abs/1205.1808

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