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Related papers: Accretion mode versus radio morphology in the LOFA…

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We present an extensive X-ray spectral analysis of the cores of 19 FRII sources in the redshift range 0.5<z<1.0 which were selected to be matched in isotropic radio power. The sample consists of 10 radio galaxies and 9 quasars. We compare…

Astrophysics · Physics 2009-11-13 E. Belsole , D. M. Worrall , M. J. Hardcastle

Misaligned Active Galactic Nuclei (MAGNs), i.e., radio galaxies and quasars with the jet not directly pointing at the observer, are a new class of GeV emitters. In low power radio galaxies (i.e., FRIs), gamma-rays are mainly produced in…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Paola Grandi , Eleonora Torresi

We present a study of the low-frequency radio properties of star forming (SF) galaxies and active galactic nuclei (AGN) up to redshift $z=2.5$. The new spectral window probed by the Low Frequency Array (LOFAR) allows us to reconstruct the…

We report the discovery of a galaxy overdensity around a Compton-thick Fanaroff-Riley type II (FRII) radio galaxy at z=1.7 in the deep multiband survey around the z=6.3 QSO SDSS J1030+0524. Based on a 6hr VLT/MUSE and on a 4hr LBT/LUCI…

Understanding the evolution of accretion activity is fundamental to our understanding of how galaxies form and evolve over the history of the Universe. We analyse a complete sample of 27 radio galaxies which includes both high-excitation…

We have assembled a sample of 37 RLQs that have been imaged with the HST in order to investigate their black hole masses, accretion rates, and the structure of their accretion disks. The black hole masses were estimated from the…

Astrophysics · Physics 2009-11-10 Jian-Min Wang , Luis C. Ho , Ruediger Staubert

Context. Cosmic rays and magnetic fields are key ingredients in galaxy evolution, regulating both stellar feedback and star formation. Their properties can be studied with low-frequency radio continuum observations, free from thermal…

Two types of correlations between the radio and X-ray luminosities ($L_R$ and $L_X$) have been found in black hole X-ray binaries. For some sources, they follow the `original' type of correlation which is described by a single power-law.…

High Energy Astrophysical Phenomena · Physics 2016-01-20 Fu-Guo Xie , Feng Yuan

The dynamical evolution and radiative properties of luminous radio galaxies and quasars of the FRII type, are well understood. As a result, through the use of detailed modeling of the observed radio emission of such sources, one can…

Astrophysics of Galaxies · Physics 2021-12-08 Anna Wojtowicz , Lukasz Stawarz , Jerzy Machalski , Luisa Ostorero

We present a search for FRI radio galaxies between 1 < z < 2 in the COSMOS field. In absence of spectroscopic redshift measurements, the selection method is based on multiple steps which make use of both radio and optical constraints. The…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-12 Marco Chiaberge , Grant Tremblay , Alessandro Capetti , F. Duccio Macchetto , Paolo Tozzi , William B. Sparks

Powerful, radio-loud active galactic nuclei (AGN) are associated with one of the most important forms of AGN feedback, and understanding how they are triggered is key to properly incorporating them into models of galaxy evolution. Here, we…

The low-luminosity active galactic nuclei in NGC 3147, NGC 4203, and NGC 4579 have been imaged at four frequencies with the Very Long Baseline Array. The galaxies are unresolved at all frequencies, with size upper limits of $10^3-10^4$…

Astrophysics · Physics 2009-11-07 James S. Ulvestad , Luis C. Ho

We present in this paper a detailed study of a new sample of large angular size FR I and FR II radio galaxies and compare the properties of the two classes. As expected, a pure morphology based distinction of FR Is and FR IIs corresponds to…

Astrophysics · Physics 2009-11-10 L. Lara , G. Giovannini , W. D. Cotton , L. Feretti , J. M. Marcaide , I. Marquez , T. Venturi

We investigate the optical emission-line flux ratios of narrow-line regions, in order to determine whether the formation of AGN jets requires specific accretion conditions. We find that bright compact radio galaxies, which are powerful…

Astrophysics · Physics 2011-02-11 Nozomu Kawakatu , Tohru Nagao , Jong-Hak Woo

In this study, we examine over 14,000 radio galaxies finely selected from Radio Galaxy Zoo (RGZ) project and provide classifications for approximately 5,900 FRIs and 8,100 FRIIs. We present an analysis of these predicted radio galaxy…

A sample of FRII radio sources in rich clusters of galaxies, both at high (z$\sim$0.5) and low (z$\sim$0) redshift, has been constructed to study the effect of environment on radio sources. Comparisons are made between the properties of…

Astrophysics · Physics 2007-05-23 Lin Wan , Ruth A. Daly

Are the FRI and FRII radio galaxies representative of the radio-loud (RL) AGN population in the local Universe? Recent studies on the local low-luminosity radio sources cast lights on an emerging population of compact radio galaxies which…

Astrophysics of Galaxies · Physics 2016-12-07 Ranieri D. Baldi , Alessandro Capetti , Gabriele Giovannini

A new scenario is suggested to explain a large diversity of the AGN radio properties and their dependence on the galaxy morphology. The scenario is based on the assumption that the growth of supermassive BHs is dominated by the accretion…

Astrophysics · Physics 2009-11-13 M. Sikora

We present an analytical model for the cosmological evolution of the FRII source population. Based on an earlier model for the intrinsic radio luminosity - linear size evolution of these objects, we construct theoretical source samples. The…

Astrophysics · Physics 2009-10-30 Christian R. Kaiser , Paul Alexander

We present morphological and photometric properties of 79 low redshift (z<0.12) radio galaxies extracted from two radio flux limited samples of radio sources. All objects are imaged in the R band and for a subsample we have also obtained B…

Astrophysics · Physics 2007-05-23 F. Govoni , R. Falomo , G. Fasano , R. Scarpa