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Related papers: Signatures of restarted activity in core-dominated…

200 papers

Maintenance-mode feedback from low-accretion rate AGN, manifesting itself observationally through radio-loudness, is invoked in all cosmological galaxy formation models as a mechanism that prevents excessive star-formation in massive…

Odd radio circles (ORCs) are newly discovered extragalactic radio objects with unknown origin. In this work, we carry out three-dimensional cosmic-ray (CR) magnetohydrodynamic simulations using the FLASH code and predict the radio…

High Energy Astrophysical Phenomena · Physics 2024-08-22 Yen-Hsing Lin , H. -Y. Karen Yang

We present results from the highest resolution polarization imaging survey of a complete sample of extragalactic radio sources carried out to date. Our sample consists of a statistically complete flat-spectrum subset of 32 AGNs from the…

Astrophysics · Physics 2009-11-07 Matthew L. Lister

We examine the fate of a dead radio source in which jet injection from the central engine has stopped at an early stage of its evolution ($t = t_j \lesssim 10^5$ yr). To this aim, we theoretically evaluate the evolution of the emission from…

High Energy Astrophysical Phenomena · Physics 2015-06-10 Hirotaka Ito , Motoki Kino , Nozomu Kawakatu , Monica Orienti

This is the fourth paper of a series investigating the AGN fuelling/feedback processes in a sample of eleven nearby low-excitation radio galaxies (LERGs). In this paper we present follow-up Atacama Large Millimeter/submillimeter Array…

Astrophysics of Galaxies · Physics 2021-12-15 I. Ruffa , I. Prandoni , T. A. Davis , R. A. Laing , R. Paladino , V. Casasola , P. Parma , M. Bureau

The energy released by an active galactic nucleus (AGN) has a strong impact on the surrounding interstellar medium (ISM). This feedback is considered to be the regulating factor for the growth of the central massive black hole, and for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Raffaella Morganti , Judit Fogasy , Zsolt Paragi , Tom Oosterloo , Monica Orienti

We discuss how the interaction between the electrons in a relativistic jet and the Cosmic Microwave Background (CMB) affects the observable properties of radio-loud AGN at early epochs. At high z the magnetic energy density in the radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 G. Ghisellini , A. Celotti , F. Tavecchio , F. Haardt , T. Sbarrato

We report the results of high-resolution 5 GHz Very Long Baseline Array and European VLBI Network observations of 36 nearby galaxies, an extension of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies (LeMMINGs) survey. Our sample…

High Energy Astrophysical Phenomena · Physics 2025-02-19 Xiaopeng Cheng , Tao An , Willem Baan , Raneri D. Baldi , David R. A. Williams-Baldwin , Bong Won Sohn , Robert Beswick , Ian M. Mchardy

The existence of double-double radio galaxies (DDRGs) is evidence for recurrent jet activity in AGN, as expected from standard accretion models. A detailed study of these rare sources provides new perspectives for investigating the AGN duty…

We report the radio continuum structure of the barred galaxy NGC 3367 with an angular resolution of 4''.5. The radio structure indicates emission from the disk and from a triple source consisting of the nucleus straddled by extended sources…

Astrophysics · Physics 2009-10-30 J. A. Garcia-Barreto , L. Rudnick , J. Franco , M. Martos

We present the results of VLBA observations of the radio galaxy 3C317, associated with the cD galaxy UGC 09799 at the centre of the cooling core cluster of galaxies A2052. These observations were carried out at 1.7 GHz, 4.9 GHz and 8.3 GHz,…

Astrophysics · Physics 2009-11-10 T. Venturi , D. Dallacasa , F. Stefanachi

Radio galaxies are a subclass of active galactic nuclei in which accretion onto the supermassive black hole releases energy via relativistic jets. The jets are not constantly active throughout the life of the host galaxy and alternate…

Astrophysics of Galaxies · Physics 2023-08-30 S. Candini , M. Brienza , A. Bonafede , K. Rajpurohit , N. Biava , M. Murgia , F. Loi , R. J. van Weeren , F. Vazza

We have used the VLBA at 15 GHz to image the structure of 132 strong compact AGN and quasars with a resolution better than one milliarcsecond and a dynamic range typically exceeding 1000 to 1. These observations were made as part of a…

Astrophysics · Physics 2009-10-30 K. I. Kellermann , R. C. Vermeulen , J. A. Zensus , M. H. Cohen

Cluster-central gigahertz peak and compact steep spectrum (CSS) sources offer an opportunity to study the earliest phases of AGN feedback, but few have yet been examined in detail. We present results from radio and X-ray observations of…

We study the particle energy distribution in the cocoon surrounding Cygnus A, using radio images between 151 MHz and 15 GHz and a 200 ks Chandra ACIS-I image. We show that the excess low frequency emission in the the lobe further from Earth…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 K. C. Steenbrugge , I. Heywood , K. M. Blundell

Radio-loud AGN are characterized by relativistic jets originating near the central supermassive black hole and forming large-scale radio sources at parsec to kiloparsec to Megaparsec distances. The jets are energetically significant, in…

Astrophysics · Physics 2007-05-23 Meg Urry

Mrk 1498 is part of a sample of galaxies with extended emission line regions (extended outwards up to a distance of $\sim$7 kpc) suggested to be photo-ionized by an AGN that has faded away or that is still active but heavily absorbed.…

We present detailed observations of MRC 0116+111, revealing a luminous, mini radio-halo of ~240 kpc diameter located at the centre of a cluster of galaxies at redshift z = 0.131. Our optical and multi-wavelength GMRT and VLA radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Joydeep Bagchi , Joe Jacob , Gopal-Krishna , Norbert Werner , Nitin Wadnerkar , Jaydeep Belapure , A. C. Kumbharkhane

In order to identify the dominant nuclear outflow mechanisms in Active Galactic Nuclei, we have undertaken deep, high resolution observations of two compact radio sources (PKS 1549-79 and PKS 1345+12) with the Advanced Camera for Surveys…

According to a currently popular paradigm, nuclear activity in quasars is sustained via accretion of material onto super-massive black holes located at the quasar nuclei. A useful tracer of the gravitational field in the vicinity of such…

Astrophysics · Physics 2007-05-23 R. Srianand , Gopal-Krishna