Infrared to x-ray spectral energy distributions of high redshift quasars
نویسندگان
چکیده
منابع مشابه
Infrared/optical Energy Distributions of High-redshift Quasars
Measurements ~t 1.2, 1.~, and 2.2 μm have been combined with visual spectrophotometry o~ 21 quasai:s havmg. redshifts z ;:;: 2.66. T~e primary result of this study is that the rest frame vism~.l/ultravIC?let contmua of the high-redshift quasars are well described by a sum of a power-law contmuum with slope -.-0.~ ~nd a 3000 A bump. The rest frame visual/ultraviolet continua of these quasars are...
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We present the results of X-ray spectroscopic observations with XMM-Newton for four high-redshift radio-loud quasars at z > 4. Among these, three objects, namely, GBB1508+5714, PMNJ0324-2918, and PKSB1251-407 do not show soft X-ray spectral flattening; the derived upper limits on assumed intrinsic absorption are (3.3 − 17.3) × 10 cm, the least of which is among the most stringent limits for z >...
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We present results of an infrared-to-X-ray study of 76 bright soft X-ray selected Seyfert galaxies discovered in the ROSAT All-Sky Survey. These objects are characterized by steep X-ray spectra in the 0.2-2.0 keV bandpass with power law energy spectral indices in the range of 1.3 to 8 and a lack of internal absorption by neutral hydrogen. Our sample selection based on hardness ratio yields a me...
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We combine photometric observations of high-redshift (z > 4) quasars, obtained at submillimetre (submm) to millimetre wavelengths, to obtain a mean far-infrared (FIR) (rest-frame) spectral energy distribution (SED) of the thermal emission from dust, parameterised by a single temperature (T ) and power-law emissivity index (β). Bestfit values are T = 41 ± 5K, β = 1.95± 0.3. Our method exploits t...
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We have compiled the largest sample of multiwavelength spectral energy distributions (SEDs) of Broad Absorption Line (BAL) quasars to date, from the radio to the X-ray. We present new Spitzer MIPS (24, 70, and 160μm) observations of 38 BAL quasars in addition to data from the literature and public archives. In general, the mid-infrared properties of BAL quasars are consistent with those of non-...
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ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 1994
ISSN: 0004-6256
DOI: 10.1086/117076