One Millimeter Continuum Observations of High Redshift Quasars
نویسنده
چکیده
Upper limits to the one-millimeter continuum flux densities of the high redshift quasars 82 1225 + 31, Ton 490, and PHL 957 are presented. The upper limit to the power observed from these quasars at I mm is, on average, ! the observed power in the continuum at La. These observations are used to constrain the temperature of a hypoth'etical dust shell which reddens the quasar line and continuum emission by an extinction optical depth sufficient to account for the anomalously low La/Ha emission line ratio observed in each of these quasars. For the quasars studied, dust shell temperatures between 25 K and 50 to 95 K are prohibited by the present data. A dust shell at a temperature within this span reradiating all the power absorbed from the quasar ultraviolet continuum would produce a one-millimeter flux density greater than the measured upper limit. The average radius of the model dust shell cannot be between 70 kpc and I Mpc.
منابع مشابه
Estimating the continuum of quasars using the articial neural networks
A lot of absorption lines are in the bluewards of Lyα emission line of quasar which is well-known as Lyαforest. Most of absorption lines in this forest belong to the Lyα absorption of the neutral hydrogen in the inter-galactic medium (IGM). For high redshift quasars and in the continuum with low and medium resolution, there are no many regions without absorption, so that, the quasar continuum i...
متن کاملFour Quasars above Redshift 6 Discovered by the Canada-france High-z Quasar Survey
The Canada-France High-z Quasar Survey (CFHQS) is an optical survey designed to locate quasars during the epoch of reionization. In this paper we present the discovery of the first four CFHQS quasars at redshift greater than 6, including the most distant known quasar, CFHQS J2329-0301 at z = 6.43. We describe the observational method used to identify the quasars and present optical, infrared, a...
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 کاملMicron Dust Emission from High Redshift Objects
We report observations of a sample of high redshift sources (1.8 ∼< z ∼< 4.7), mainly radio-quiet quasars, at 350μm using the SHARC bolometer camera at the Caltech Submillimeter Observatory. Nine sources were detected (∼> 4σ) and upper limits were obtained for 11 with 350μm flux density limits (3 σ) in the range 30 125mJy. Combining published results at other far-infrared and millimeter wavelen...
متن کاملDust emission and star formation toward a redshift 5.5 QSO
We report observations of the low-luminosity z = 5.50 quasar RD J030117+002025 (RD0301 hereafter) at 250 GHz (1.20 mm) using the Max-Planck Millimeter Bolometer (MAMBO) array at the IRAM 30-meter telescope. The quasar was detected with a 1.2 mm flux density of 0.87 ± 0.20 mJy. The lack of detectable 1.4 GHz radio emission indicates that the millimeter emission is of thermal nature, making RD030...
متن کامل