Dust in PG quasars as seen by ISO
نویسندگان
چکیده
Infrared to millimeter spectral energy distributions (SEDs) have been obtained for a random sample of 17 Palomar Green quasars. The observations were carried out between 4.8 and 200 μm with ISO and supplemented for ten sources with IRAM at 1.3 mm. Eight sources were detected in the far infrared for the first time. The SEDs provide evidence for considerable dust emission and do not support the existence of dust-free, naked quasars. The SEDs resemble those of warm ultraluminous infrared galaxies (ULIRGs). The SEDs show a variety of shapes (power-law, mid-infrared dominated, and far-infrared dominated), suggesting the influence of different heating mechanisms. The midand far-infrared luminosities are correlated, suggesting a dependence between the heating mechanisms. The role of AGNs and starbursts for the dust heating is discussed, as well as the link between general ULIRGs and dust-enshrouded quasars.
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