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Absorption in X-ray spectra of high-redshift quasars
(IOP Publishing, 1994)
We present evidence that X-ray absorption is common in high-redshift quasars. We have studied six high-redshift (z approximately 3) quasars with the ROSAT Position Sensitive Proportional Counter (PSPC) of which four are ...
Infrared to x-ray spectral energy distributions of high redshift quasars
(IOP Publishing, 1994)
We have observed 14 quasars with z greater than 2.8 with the ROSAT-PSPC, and detected 12 of them, including the z=4.11 quasar 0000-263. We present the first x-ray spectrum of a radio quiet quasar with z greater than 3, ...
X-ray spectral evolution of high redshift quasars
(IOP Publishing, 1994)
At z approx. equals 3, the x-ray spectra of radio-loud and radio-quiet quasars are different. High-redshift radio-quiet quasars either have large absorbing columns, NH, and steeper power law spectral indices, alphaepsilon, ...
Atlas of quasar energy distributions
(IOP Publishing, 1994)
We present an atlas of the spectral energy distributions (SEDs) of normal, nonblazar, quasars over the whole available range (radio to 10 keV X-rays) of the electromagnetic spectrum. The primary (UVSX) sample includes 47 ...