Results 11 to 20 of about 4,973 (222)
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.
D. Kozieł-Wierzbowska +6 more
openaire +4 more sources
Search and Characterization of Remnant Radio Galaxies in the XMM-LSS Deep Field
The Astrophysical Journal, 2023 The remnant phase of a radio galaxy is characterized by the cessation of active galactic nuclei activity, resulting in the jets ceasing to feed plasma to the radio lobes.
Sushant Dutta +5 more
doaj +1 more source
The Astrophysical Journal, 2023 The sampling strategy of the Transiting Exoplanet Survey Satellite (TESS) makes TESS light curves extremely valuable for investigating the high cadence optical variability of active galactic nuclei (AGN).
Krista Lynne Smith, Lia F. Sartori
doaj +1 more source
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
openaire +3 more sources
FRAMEx. IV. Mechanical Feedback from the Active Galactic Nucleus in NGC 3079
The Astrophysical Journal, 2023 Using the Very Long Baseline Array, we observed the active galactic nucleus (AGN) in NGC 3079 over a span of six months to test for variability in the two main parsec-scale radio components, A and B , which lie on either side of the AGN.
Luis C. Fernandez +3 more
doaj +1 more source
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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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.
openaire +2 more sources
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.
Tombesi F. +7 more
openaire +4 more sources
Intraday radio variability in active galactic nuclei
New Astronomy Reviews, 1999 Rapid flux density variations on timescales of the order of a day or less (Intraday Variability, IDV) in the radio regime are a common phenomenon within the blazar class. Observations with the 100m telescope of the MPIfR showed that the variations occur not only in total intensity, but also in the polarized intensity and in polarization angle.
Kraus, A., Witzel, A., Krichbaum, T. P.
openaire +2 more sources
Jetted Active Galactic Nuclei [PDF]
, 2018 The term "blazar" refers to a cosmic source with a relativistic jet viewed at a small angle, so that the electromagnetic emission is affected by beaming.
Foschini, Luigi (5113958) +1 more
core +1 more source