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The X-ray and ultraviolet absorbing outflow in 3C 351
(IOP Publishing, 1994)
3C 351 (z = 0.371), and X-ray-'quiet' quasar, is one of the few quasars showing signs of a 'warm absorber' in its X-ray spectrum; i.e., partially ionized absorbing material in the line of sight whose opacity depends on its ...
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 ...
The complex optical to soft x-ray spectrum of the low-redshift radio-quiet quasars
(IOP Publishing, 1994)
Eight high signal-to-noise ROSAT Position Sensitive Proportional Counter (PSPC) observations of six low-redshift (o.048 less than z less than 0.155) radio-quiet quasars have been analyzed to study ant soft excess. All the ...
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, ...
Consistency of spherical, gravity-dominated dynamics with quasar high-ionization emission-line profiles
(IOP Publishing, 1993)
Line profile data are used to test a simple kinematic model - spherically symmetric gravitational free fall - in which the number of free parameters is limited by requiring physical self-consistency. The predictions of ...
PKS 0483-436 - A high-redshift quasar with strong X-ray absorption
(IOP Publishing, 1992)
The first X-ray spectrum of a high-redshift (z = 2.85) quasar is reported. The Rosat PSPC spectrum of PKS 0438-436, covering 0.3-9 keV in the quasar's rest frame, reveals unexpected absorption of about 1 x 10 exp 22/sq cm, ...
The ROSAT spectrum of 3C 351 - A warm absorber in an X-ray-'quiet' quasar?
(IOP Publishing, 1993)
3C 351 is one of the most X-ray-quiet radio quasars (alpha(ox) about 1.6). We have observed 3C 351 with the ROSAT position sensitive proportional counter (PSPC) and find a complex X-ray spectrum which is not well reproduced ...
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 ...
X-ray absorption toward the red quasar 3C 212
(IOP Publishing, 1994)
A Roentgen Satellite (ROSAT) X-ray spectrum of the z = 1.049 'red quasar' 3C 212 has a strong low-energy cutoff. The spectrum can be fitted with a power law (of energy index 1.4(+0.8, -0.6) with low-energy photoelectric ...
EXOSAT X-ray spectra of quasars
(IOP Publishing, 1992)
Measurements of the X-ray spectra in the 0.1-10-keV energy range for 17 AGN (mostly PG quasars) using the Exosat Low and Medium Energy arrays are presented. For each object, the best-fit spectral parameters in the medium-energy ...