Results 181 to 190 of about 18,849 (212)

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
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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
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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 ...
V. K. Kapahi, D. J. Saikia
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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
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Intrinsic variations of the double quasar 0957 + 56 AB

Nature, 1981
Spectroscopic evidence strongly suggests that the two quasars 0957 + 56 A and B are images produced by the gravitational lensing of a single distant quasar (at z = 1.41) by a giant elliptical galaxy and its attendant cluster (at z = 0.36)1–6. It has also been suggested that the quasar is an intrinsic variable7,8.
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Microlensing constraints on MACHO masses from the double quasar Q0957+561

New Astronomy Reviews, 1998
Abstract Gravitational lensing can be used to determine whether the dark matter in galactic halos is in the form of objects of stellar or sub-stellar mass. Searches for these MACHOs (MAssive Compact Halo Objects) have become popular in our own Milky Way from studies of the rare events of a MACHO magnifying a star in the Large Magellanic Cloud.
Joachim Wambsganss, Robert Schmidt
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Double peaked broad line profiles — edge on accretion disks or double quasar nuclei?

2008
It is pointed out that a significant fraction (over 50%) of quasars do not show smooth symmetric “logarithmic” broad line profiles, but instead show double broad line peaks, usually unequal in brightness, always one blueshifted and one redshifted relative to the systemic velocity.
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93.double quasar image

2022
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Estimation of model parameters in the selected double imaged quasars

Astronomical and Astrophysical Transactions
This article presents the results of modeling based on observations of the gravitationally lensed quasars SDSS J0806+2006 and SDSS J2124+1632 observed at the Maidanak Observatory in 2017-2022 and 2018-2022. The value of the Hubble constant H0= 61.4±7 for the SDSS J0806+2006 GLK is estimated, and the redshift of the lensing galaxy for the SDSS J2124 ...
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Double gravitationally lensed quasar J1721+8842 observed at the Maidanak observatory

Astronomical and Astrophysical Transactions
This paper presents the results of observations and the light curve of the unique doubly gravitationally lensed quasar J1721+8842, observed at the Maidanak observatory from 2018 to 2024. It also includes the results of best image reduction using a deconvolution method that separates 6 lensed point-like images.
I.M. ASFANDIYAROV, S.A. EHGAMBERDIEV, O.A. BURKHONOV   +2 more
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