Results 11 to 20 of about 166 (155)
The Radio Properties of Radio-Quiet Quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 1997 3 pages, Latex, presented at the ESO/IAC conference on `Quasar Hosts' 24-27 September 1996, (uses the LAMUPHYS macro from Springer-Verlag)
Kukula, M +3 more
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On the origin of radio emission in radio-quiet quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 2008 The radio emission in radio loud quasars originates in a jet carrying relativistic electrons. In radio quiet quasars (RQQs) the relative radio emission is ~10^3 times weaker, and its origin is not established yet. We show here that there is a strong correlation between the radio luminosity (L_R) and X-ray luminosity (L_X) with L_R~10^-5L_X, for the ...
Laor, Ari, Behar, Ehud
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The radio structure of radio-quiet quasars [PDF]
Astronomy & Astrophysics, 2006 14 pages, 15 figures, accepted for publication in A& ...
Leipski, C. +3 more
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Jetted radio-quiet quasars at z > 5 [PDF]
Astronomy & Astrophysics, 2021 We report on the JVLA observations of three high-redshift active galactic nuclei (AGNs) that have black hole masses estimated to be among the largest known. Two of them, SDSS J0100+2802 and SDSS J0306+1853 at redshift 6.326 and 5.363, respectively, are radio-quiet AGNs according to the classic definition, while the third (B2 1023+25 at z = 5.284) is a ...
T. Sbarrato +3 more
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On the Origin of Radio Core Emission in Radio-quiet Quasars [PDF]
The Astrophysical Journal, 2007 We present a model for the radio emission from radio-quiet quasar nuclei. We show that a thermal origin for the high brightness temperature, flat spectrum point sources (known as radio ``cores'') is possible provided the emitting region is hot and optically-thin.
Blundell, K, Kuncic, Z
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What drives the radio slopes in radio-quiet quasars? [PDF]
Monthly Notices of the Royal Astronomical Society, 2018 The origin of the radio emission in Radio Quiet (RQ) quasars is not established yet. Important hints can be provided by the spectral slope, and its relation to other emission properties. We compiled the highest resolution 5 and 8.4 GHz VLA observations available of the RQ optically selected PG quasars at z<0.5. We derive the 5-8.4 GHz spectral slope,
Ari Laor, Ranieri D Baldi, Ehud Behar
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Accretion and star formation in ‘radio-quiet’ quasars [PDF]
Proceedings of the International Astronomical Union, 2019 AbstractRadio observations allow us to identify a wide range of active galactic nuclei (AGN), which play a significant role in the evolution of galaxies. Amongst AGN at low radio-luminosities is the ‘radio-quiet’ quasar (RQQ) population, but how they contribute to the total radio emission is under debate, with previous studies arguing that it is ...
White, Sarah +6 more
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Optically Quiet Quasars – Radio and Optical Investigations [PDF]
Symposium - International Astronomical Union, 1994 The activity in the nuclei of bright galaxies could arise from a number of sources: they may contain compact variable radio sources, they may be strong IR/optical/X–ray continuum sources, or they may have strong emission lines. Usually but not always these properties go together as in radio loud quasars.
Chidi E. Akujor +3 more
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Radio and Optical Observations of “Optically Quiet Quasars” [PDF]
Symposium - International Astronomical Union, 1986 In recent years a number of very steep spectrum, compact radio sources have been discovered (e.g. Cotton 1983, Cotton and Owen 1985, Ulvestad 1985) which have no optical counterpart to the limit of the Palomar Sky Survey. VLBI observations of a number of these have confirmed the very compact (<10 mas) nature of several of these sources.
W. D. Cotton, F. N. Owen, M. J. Mahoney
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Dependence of the Radio Emission on the Eddington Ratio of Radio-quiet Quasars
The Astrophysical Journal, 2022 Abstract Roughly 10% of quasars are “radio-loud,” producing copious radio emission in large jets. The origin of the low-level radio emission seen from the remaining 90% of quasars is unclear. Observing a sample of eight radio-quiet quasars with the Very Long Baseline Array, we discovered that their radio properties depend strongly on ...
Abdulla Alhosani +6 more
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