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This is the first paper of a series exploring the multi-frequency properties of a sample of eleven nearby low excitation radio galaxies (LERGs) in the southern sky. We are conducting an extensive study of different galaxy components (stars,…

We present observations of two radio galaxies, J1835+620 and 3C338, both with signs of having passed through different stages of core activity. The former presents two symmetric and bright components within a typical FR II structure,…

Structures of radio galaxies have the potential to reveal inconstancy in the axis of the beams, which reflect the stability in the spin axis of the supermassive black hole at the centre. We present radio observations of the giant radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 L. Saripalli , J. M. Malarecki , R. Subrahmanyan , D. H. Jones , L. Staveley-Smith

The radio jets of an active galactic nucleus (AGN) can heat up the gas around a host galaxy and quench star formation activity. The presence of a radio jet could be related to the evolutionary path of the host galaxy and may be imprinted in…

Astrophysics of Galaxies · Physics 2023-05-03 Xuechen Zheng , Huub Röttgering , Arjen van der Wel , Michele Cappellari

Within the MOJAVE VLBA program (Monitoring of Jets in AGN with VLBA Experiments), we have accumulated observational data at 15 GHz for hundreds of jets in $\gamma$-ray bright active galactic nuclei since the beginning of the Fermi…

High Energy Astrophysical Phenomena · Physics 2021-12-23 I. G. Kramarenko , A. B. Pushkarev , Y. Y. Kovalev , M. L. Lister , T. Hovatta , T. Savolainen

Less than $200$ radio-loud active galactic nuclei (AGN) are known above redshift $4$. Around $40$ of them have been observed at milliarcsecond (mas) scale resolution with very long baseline interferometry (VLBI) technique. Some of them are…

Jets of high-redshift active galactic nuclei (AGNs) can be used to directly probe the activity of the black holes in the early Universe. Radio sources with jets misaligned with respect to the line of sight are expected to dominate the…

High Energy Astrophysical Phenomena · Physics 2021-08-18 Yingkang Zhang , Tao An , Sándor Frey , Xiaolong Yang , Máté Krezinger , Oleg Titov , Alexey Melnikov , Pablo de Vicente , Fengchun Shu , Ailing Wang

Using recent high-resolution radio observations of a large sample of Seyfert galaxies (Roy et al. 1994), we analyze the relations between the compact radio core emission and several nuclear and host galaxy properties. Seyfert nuclei hosted…

Astrophysics · Physics 2008-11-26 Giuliano Giuricin , Dario Fadda , Marino Mezzetti

Seyfert galaxies and quasars were first discovered through optical and radio techniques, but in recent years high-energy emission, that can penetrate central gas and dust, has become essentially the defining characteristic of an AGN. AGNs…

Astrophysics · Physics 2007-05-23 D. M. Worrall

(Abridged) In this article, we discuss the state of ``AGN feedback'' in radio-quiet (RQ) AGN. This study involves heterogeneous samples of nearby Seyfert and LINER galaxies as well as QSOs that have been observed at low radio frequencies…

Astrophysics of Galaxies · Physics 2023-02-15 Preeti Kharb , Silpa Sasikumar

Many low-luminosity active galactic nuclei (AGNs) contain a compact radio core which can be observed with high angular resolution using very long baseline interferometry (VLBI). Combining arcsec-scale structural information with…

Astrophysics of Galaxies · Physics 2020-04-06 Máté Krezinger , Sándor Frey , Zsolt Paragi , Roger Deane

Winged, or X-shaped, radio sources form a small class of morphologically peculiar extragalactic sources. We present multi-frequency radio observations of two such sources. We derive maximum ages since any re-injection of fresh particles of…

Astrophysics · Physics 2009-11-07 J. Dennett-Thorpe , P. A. G. Scheuer , R. A. Laing , A. H. Bridle , G. G. Pooley , W. Reich

We have analyzed the parsec-scale jet kinematics of 447 bright radio-loud AGN, based on 15 GHz VLBA data obtained between 1994 August 31 and 2019 August 4. We present new total intensity and linear polarization maps obtained between 2017…

High Energy Astrophysical Phenomena · Physics 2021-12-14 M. L. Lister , D. C. Homan , K. I. Kellermann , Y. Y. Kovalev , A. B. Pushkarev , E. Ros , T. Savolainen

We have surveyed two large samples of nearby low-luminosity AGN with the VLA to search for flat-spectrum radio cores, similar to Sgr A* in the Galactic Center. Roughly one third of all galaxies are detected (roughly one half if HII…

Astrophysics · Physics 2015-06-24 Heino Falcke , Neil M. Nagar , Andrew S. Wilson , Luis C. Ho , Jim S. Ulvestad

A small number of double-lobed radio galaxies (17 from our own census of the literature) show an additional pair of low surface brightness `wings', thus forming an overall `X'-shaped appearance. The origin of the wings in these radio…

Astrophysics · Physics 2008-11-26 C. C. Cheung

We present a study of the radio properties of the dominant early-type galaxies in 26 galaxy groups, the high-richness sub-sample of the Complete Local-volume Groups Sample (CLoGS). Combining new 610 MHz and 235 MHz observations of 21 groups…

Astrophysics of Galaxies · Physics 2018-07-31 Konstantinos Kolokythas , Ewan O'Sullivan , Somak Raychaudhury , Simona Giacintucci , Myriam Gitti , Arif Babul

We present sub-arcsecond resolution multi-frequency (8 and 22 GHz) VLA images of five low power compact (LPC) radio sources, and phase referenced VLBA images at 1.6 GHz of their nuclear regions. At the VLA resolution we resolve the…

Astrophysics · Physics 2009-11-11 M. Giroletti , G. Giovannini , G. B. Taylor

The cocoons surrounding powerful radio sources can be extensive if the jet that feeds the cocoon is light and supersonic. They have been shown to remain overpressured with respect to the ambient medium for most of the life time of the…

Astrophysics · Physics 2015-06-24 Biman B. Nath

We have examined a subset of 11 active galactic nuclei (AGN) drawn from a sample of 87 objects that possess double-peaked optical emission line spectra, as put forward by Wang et al. (2009a) and are detectable in the FIRST survey at radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 S. J. Tingay , R. B. Wayth

We investigate radio-mode AGN activity among post-starburst galaxies from the Sloan Digital Sky Survey to determine whether AGN feedback may be responsible for the cessation of star formation. Based on radio morphology and radio-loudness…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Min-Su Shin , Michael A. Strauss , Rita Tojeiro
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