ISO continuum observations of quasars at z = 1 - 4 ⋆ I . Spectral energy distributions of quasars from the UV to far - infrared
نویسنده
چکیده
Eight luminous quasars with −30 < MB < −27 at z = 1.4 3.7 have been observed in the midand far-infrared using ISO. All the quasars have been detected in the mid-infrared bands of ISOCAM, while no far-infrared detections have been made with ISOPHOT. SEDs (Spectral Energy Distributions) from the UV to far-infrared have been obtained while supplementing ISO observations with photometry in the optical and nearinfrared made from the ground within 17 months. The SEDs are compared with the MED (Mean spectral Energy Distributions) of low-redshift quasars with −27 < MB < −22. It is shown that our far-infrared observations were limited by confusion noise due to crowded sources.
منابع مشابه
How many active galaxies and QSOs will future Space Missions detect ?
Averaged spectral energy distributions (SEDs) of active and starburst galaxies from the 12μm sample in the Local Universe and quasars, from an optically selected sample at a mean redshift 〈z〉=0.7 are built from optical, near-IR and far-IR (IRAS and ISO) photometric observations. These SEDs are then used to predict at various redshifts the number of Seyfert type 1 and type 2, starburst, normal g...
متن کاملThe far-infrared emission of radio loud and radio quiet quasars
Continuum observations at radio, millimetre, infrared and soft X-ray energies are presented for a sample of 22 quasars, consisting of flat and steep spectrum radio loud, radio intermediate and radio quiet objects. The primary observational distinctions, among the different kinds of quasars in the radio and IR energy domains are studied using large observational datasets provided by ISOPHOT on b...
متن کاملA search for signatures of quasar evolution: Comparison of the shapes of the rest-frame optical/UV continua of quasars at z> 3 and z ∼ 0.1 1
A search for signatures of quasar evolution: Comparison of the shapes of the rest-frame optical/UV continua of quasars at z > 3 and z ∼ 0.1 ABSTRACT For 15 bright (V< 17.5), high redshift (z > 3) quasars, we have obtained infrared spectra and photometry, and optical spectrophotometry and photometry, which we use to construct their spectral energy distributions (SEDs) from λ rest ∼ 1285 − 5100Å....
متن کاملMicron Dust Emission from High Redshift Quasars
We report detections of six high-redshift (1.8 ≤ z ≤ 6.4), optically luminous, radio-quiet quasars at 350 μm, using the SHARC II bolometer camera at the Caltech Submillimeter Observatory. Our observations double the number of high-redshift quasars for which 350 μm photometry is available. By combining the 350 μm measurements with observations at other submillimeter/millimeter wavelengths, for e...
متن کاملDust in PG quasars as seen by ISO
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 e...
متن کامل