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We report new continuum observations of fourteen z~6 quasars at 250 GHz and fourteen quasars at 1.4 GHz. We summarize all recent millimeter and radio observations of the sample of the thirty-three quasars known with 5.71<=z<=6.43, and present a study of the rest frame far-infrared (FIR) properties of this sample. These quasars were observed with the Max Plank Millimeter Bolometer Array (MAMBO) at 250 GHz with mJy sensitivity, and 30% of them were detected. We also recover the average 250 GHz flux density of the MAMBO undetected sources at 4 sigma, by stacking the on-source measurements. The derived mean radio-to-UV spectral energy distributions (SEDs) of the full sample and the 250 GHz non-detections show no significant difference from that of lower-redshift optical quasars. Obvious FIR excesses are seen in the individual SEDs of the strong 250 GHz detections, with FIR-to-radio emission ratios consistent with that of typical star forming galaxies. Most 250 GHz-detected sources follow the L_{FIR}--L_{bol} relationship derived from a sample of local IR luminous quasars (L_{IR}>10^{12}L_{odot}), while the average L_{FIR}/L_{bol} ratio of the non-detections is consistent with that of the optically-selected PG quasars. The MAMBO detections also tend to have weaker Lyalpha emission than the non-detected sources. We discuss possible FIR dust heating sources, and critically assess the possibility of active star formation in the host galaxies of the z~6 quasars. The average star formation rate of the MAMBO non-detections is likely to be less than a few hundred M_{odot} yr^{-1}, but in the strong detections, the host galaxy star formation is probably at a rate of gtrsim10^{3} M_{odot} yr^{-1}, which dominates the FIR dust heating.
We report observations of three SDSS z>6 QSOs at 250 GHz (1.2mm) using the 117-channel Max-Planck Millimeter Bolometer (MAMBO-2) array at the IRAM 30-meter telescope. J1148+5251 (z=6.41) and J1048+4637 (z=6.23) were detected with 250 GHz flux densiti
We present observations of four z>= SDSS quasars at 350 micron with the SHARC-II bolometer camera on the Caltech Submillimeter Observatory. These are among the deepest observations that have been made by SHARC-II at 350 micron, and three quasars are
The highest-redshift quasars are still rare and valuable objects for observational astrophysics and cosmology. They provide important constraints on the growth of the earliest supermassive black holes in the Universe, and information on the physical
We study the far-infrared emission from the nearby spiral galaxy M33 in order to investigate the dust physical properties such as the temperature and the luminosity density across the galaxy. Taking advantage of the unique wavelength coverage (100, 1
We test emission models of circum-nuclear dust torii around quasars, at low and high redshifts, by using a large collection of photometric data for an unbiased sample of 120 optically-selected objects with millimetric and sub-millimetric fluxes, incl