Results 201 to 210 of about 512 (214)

“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 ...
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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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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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The nature of double-peaked lines in Sy 1 and quasars

AIP Conference Proceedings, 2001
We have analyzed the Lyα, Hβ and Hα line profiles of three active galactic nuclei: quasar 3C390.3 and two Seyfert 1 galaxies; Akn 120 and III Zw2. The blue- and red-shifted broad Gaussian components which are present in all considered 3C390.3 and Akn 120 lines cannot be explained by an accretion disk model because of the lines’ variation on longer time-
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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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93.double quasar image

2022
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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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An improved test of the binary black hole hypothesis for quasars with double-peaked broad Balmer lines

Monthly Notices of the Royal Astronomical Society, 2020
Anh Doan, Michael Eracleous, Jessie C Runnoe   +2 more
exaly  

Gravitationally lensed quasars inGaia– III. 22 new lensed quasars fromGaiadata release 2

Monthly Notices of the Royal Astronomical Society, 2019
C Lemon, Matthew W Auger, Richard G Mcmahon   +2 more
exaly