Results 1 to 10 of about 23,272 (235)
The radio emission from active galactic nuclei [PDF]
Astronomy & Astrophysics, 2021 Context. For nearly seven decades, astronomers have been studying active galaxies, that is to say, galaxies with actively accreting central supermassive black holes: active galactic nuclei (AGN). A small fraction are characterized by luminous, powerful radio emission: This class is known as radio-loud AGN.
Pieter Barthel +8 more
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Identifying Radio-active Galactic Nuclei among Radio-emitting Galaxies [PDF]
The Astrophysical Journal, 2021 Abstract Basing our analysis on ROGUE I, a catalog of over 32,000 radio sources associated with optical galaxies, we provide two diagnostics to select the galaxies where the radio emission is dominated by an active galactic nucleus (AGN), referred to in the paper as radio-AGNs. Each of these diagnostics can be applied independently.
F. R. Herpich +8 more
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ENERGETICS AND LIFETIMES OF LOCAL RADIO ACTIVE GALACTIC NUCLEI [PDF]
The Astrophysical Journal, 2015 We present a model describing the evolution of Fanaroff-Riley type I and II radio AGN, and the transition between these classes. We quantify galaxy environments using a semi-analytic galaxy formation model, and apply our model to a volume-limited low redshift ($0.03 \leqslant z \leqslant 0.1$) sample of observed AGN to determine the distribution of jet
Ross J. Turner, Stanislav S. Shabala
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Recurrent radio activity in active galactic nuclei [PDF]
EPJ Web of Conferences, 2012 There has been a growing body of persuasive evidence to indicate that AGN activity, powered by mass accretion onto a supermassive black hole, can involve multiple episodes. Thus thinking of jet activity as occurring within a unique brief period in the life of a galaxy is no longer valid.
Jamrozy M.
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Low-luminosity radio-loud active galactic nuclei [PDF]
Proceedings of 8th European VLBI Network Symposium — PoS(8thEVN), 2007 I review observational properties of low power radio loud AGN. High resolution VLBI observations allow the estimate of the jet velocity and orientation with respect to the line of sight and the determination of the Doppler factor. These data reveal rich structures, including two-sided jets and secondary components. New results on 1144+35, a giant radio
Giovannini, Gabriele +1 more
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BeppoSAXView of Radio‐loud Active Galactic Nuclei [PDF]
The Astrophysical Journal, 2006 ApJ accepted, 33 pages, 6 ...
Mariateresa Fiocchi +3 more
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ON THE RADIO DICHOTOMY OF ACTIVE GALACTIC NUCLEI [PDF]
The Astrophysical Journal, 2016 ABSTRACT It is still a mystery why only a small fraction of active galactic nuclei (AGNs) contain relativistic jets. A strong magnetic field is a necessary ingredient for jet formation, however, the advection of the external field in a geometrically thin disk is inefficient.
Xinwu Cao
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Ultrafast outflows in radio-loud active galactic nuclei [PDF]
Monthly Notices of the Royal Astronomical Society, 2014 Recent X-ray observations show absorbing winds with velocities up to mildly-relativistic values of the order of ~0.1c in a limited sample of 6 broad-line radio galaxies. They are observed as blue-shifted Fe XXV-XXVI K-shell absorption lines, similarly to the ultra-fast outflows (UFOs) reported in Seyferts and quasars.
James Reeves +9 more
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The radio dichotomy of active galactic nuclei [PDF]
Publications of the Astronomical Society of Japan, 2022 Abstract The question of radio dichotomy in active galactic nuclei (AGNs) is still in debate, even though it has been discussed for more than 40 years. In order to solve this old riddle, we collect a sample of AGNs with optical B band and radio 6 cm wavelength data to analyze the radio loudness log R. Our results indicate a separation of
Xiao, Hubing +4 more
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Radio-loud and Radio-quiet Active Galactic Nuclei [PDF]
The Astronomical Journal, 1999 We generated a sample of 409 AGNs for which both the radio luminosity at 5 GHz and the line luminosity in [OIII] 5007 have been measured. The radio luminosity spans a range of ten orders of magnitude, and the [OIII] line luminosity spans a range of eight orders of magnitude --- both considerably larger than the ranges in previous studies.
Mario Livio +3 more
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