Results 181 to 190 of about 1,391,040 (211)

Radio structure of the ‘double quasar’ 4C11.50

Nature, 1974
WAMPLER et al.1 have recently announced the discovery of a close pair of optical quasars associated with the radio source 4C11.50. The brighter quasar (a) has a redshift of 0.436, whereas its companion (b), 4.8 arc s away in position angle 95°, has a much larger redshift of 1.901.
D. STANNARD, P. N. WILKINSON, R. S. WARWICK, R. J. DAVIS   +3 more
openaire   +1 more source

Relativistic beaming in the central components of double radio quasars

Journal of Astrophysics and Astronomy, 1982
Using a large sample of 78 well-observed double quasars, we have investigated several consequences of the relativistic beaming model. In this model the ratio of the strengths of the central component and outer lobes of a double source depends on whether the jet axis lies close to or away from the line of sight, If this is the actual situation, the ...
Dhruba Jyoti Saikia, V K Kapahi
exaly   +2 more sources

Gravitationally lensed quasars in Gaia – II. Discovery of 24 lensed quasars [PDF]

Monthly Notices of the Royal Astronomical Society, 2018
We report the discovery, spectroscopic confirmation, and preliminary characterization of 24 gravitationally lensed quasars identified using Gaia observations.
Richard G. McMahon, Cameron Lemon, Matthew W Auger   +2 more
exaly   +3 more sources

Superluminal motion in the double-lobed quasar 3C263

Nature, 1987
The detection of superluminal motion in the quasar 3C263 is reported. The milliarcsecond structure of this source consists of two nearly unresolved components whose separation is increasing at a rate of 0.06 + or - 0.02 marcsec/yr. This corresponds to an expansion speed of 2.7 + or - 0.9 c (H/0/ = 55 km/s/Mpc, q/0/ = 0.05).
J. A. Zensus, D. H. Hough, R. W. Porcas
openaire   +1 more source

Variability of the double quasar 0957 + 561 A, B

Nature, 1981
Evidence suggests that the double nature of the quasar 0957 + 561 A, B results from the influence of an intervening gravitational lens on the light from a more distant, single quasar. The nearly identical spectral characteristics of the two objects have been established1–3 and have been the incentive for interpreting the two apparent objects as images ...
Joseph S. Miller, Robert R. J. Antonucci, William C. Keel   +2 more
openaire   +1 more source

Quasar image doubling associated with absorption systems

Nature, 1979
Ever since their discovery the origin of quasar absorption lines has been a subject of considerable controversy (see ref. 1). In this note we consider the consequences of the hypothesis that at least some of the absorption lines arise in galaxies. These galaxies could be ordinary ones with 50–100 kpc haloes2, or perhaps more compact but more common (at
Julian H. Krolik, John Kwan
openaire   +1 more source

Ton 155 and 156: a Double Quasar?

Nature Physical Science, 1972
Janes and Lynds1 have shown that Ton 156 is a quasar, although they were unable to determine a satisfactory redshift. My spectroscopic observations made with the Mauna Kea 224 cm telescope, have shown that Ton 155, located at about 35″ arc north preceding Ton 156, is also a quasar and have allowed redshifts to be determined for both objects.
openaire   +1 more source

“Double quasar” could be gravity effect

Physics Today, 1979
Earlier this year observations of a close pair of visible astronomical sources previously identified with a quasar candidate from low-resolution radio data appeared to indicate that the pair is actually a single object doubled by the effect of a “gravitational lens.” More recent radio observations make some difficulties for the hypothesis, but do not ...
openaire   +1 more source

Superluminal quasar 3C179 with double radio lobes

Nature, 1981
VLBI observations of the quasar 3C179 reveal that its two milli arc second components have an apparent relative velocity of 7.6 times the velocity of light. This is the fifth radio source in which ‘superluminal’ motion has been reported but the first which also exhibits double lobe structure on the arc second scale. Statistical arguments which apply to
openaire   +1 more source

The Double Quasar 0957+561: A Radio Study at 6-Centimeters Wavelength

Science, 1979
The optical double quasar 0957+561 has been interpreted as the gravitational double image of a single object. A radio map made with the Very Large Array of the National Radio Astronomy Observatory shows unresolved sources coincident with the optical images as well as a complex of related extended emission.
D H, Roberts, P E, Greenfield, B F, Burke   +2 more
openaire   +2 more sources