Results 11 to 20 of about 17,110 (224)
Frontiers in Astronomy and Space Sciences, 2022 Given their extremely large distances and small apparent sizes, quasars are generally considered as objects with near-zero parallax and proper motion.
Qi-Qi Wu +15 more
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Quasars Probing Quasars. I. Optically Thick Absorbers near Luminous Quasars [PDF]
The Astrophysical Journal, 2006 With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We search 149 moderate resolution background quasar spectra, from Gemini, Keck, the MMT, and the SDSS to survey Lyman Limit Systems (LLSs) and Damped Ly-alpha systems (DLAs) in the vicinity of 1.8 < ...
Hennawi, Joseph F. +13 more
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A HUBBLE DIAGRAM FOR QUASARS [PDF]
The Astrophysical Journal, 2015 ApJ ...
Lusso E., RISALITI, GUIDO
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Science, 1986 In the quarter century since the first optical identification of a "radio star" (3C 48), astronomers have come to general agreement that the underlying quasar energy source is accretion onto a massive black hole. There is much less agreement on the detailed physics of the processes by which this energy is converted to the forms observed, but this has ...
Trimble, Virginia, Woltjer, Lodewijk
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Two Close Separation Quasar-Quasar Pairs in the Large Bright Quasar Survey [PDF]
The Astronomical Journal, 1998 Accepted for publication in the Astronomical Journal, Paper, 4 Figures + 1 ...
Hewett, Paul C. +3 more
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Galaxies, 2021 The radiative and jet power in active galactic nuclei is generated by accretion of material on to supermassive galactic-centre black holes. For quasars, where the radiative power is by definition very high, objects with high radio luminosities form 10 ...
Gülay Gürkan +5 more
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The Astrophysical Journal Letters, 2023 Studies of rest-frame optical emission in quasars at z > 6 have historically been limited by the wavelengths accessible by ground-based telescopes. The James Webb Space Telescope (JWST) now offers the opportunity to probe this emission deep into the ...
Jinyi Yang +55 more
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Massive ionized outflows in quasars [PDF]
, 2017 The most luminous quasars in the Hamburg- ESO (HE) survey show, at a high prevalence, CIV λ1549 and [OIII]λλ4959,5007 emission line profiles with high-amplitude blueshifts which indicate outflows occurring over a wide range of spatial scales.
Del Olmo, Ascension +6 more
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The Pan-STARRS1 z > 5.6 Quasar Survey. II. Discovery of 55 Quasars at 5.6 < z < 6.5
The Astrophysical Journal Supplement Series, 2023 The identification of bright quasars at z ≳ 6 enables detailed studies of supermassive black holes, massive galaxies, structure formation, and the state of the intergalactic medium within the first billion years after the Big Bang.
Eduardo Bañados +22 more
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Proceedings of the International Astronomical Union, 2014 AbstractAlthough the extragalactic nature of 3C 48 and other quasi stellar radio sources was discussed as early as 1960 by John Bolton and others, it was rejected largely because of preconceived ideas about what appeared to be unrealistically high radio and optical luminosities.
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