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Related papers: RAiSE II: resolved spectral evolution in radio AGN

200 papers

The appearance of active galactic nuclei (AGN) depends so strongly on orientation that our current classification schemes are dominated by random pointing directions instead of more interesting physical properties. Light from the centers of…

Astrophysics · Physics 2011-07-18 C. Megan Urry , Paolo Padovani

Powerful extended radio galaxies in the 3CR survey are observed out to redshifts of about 2. For redshifts greater than about 0.3, the average lobe-lobe size of the sources decreases monotonically with redshift for all reasonable…

Astrophysics · Physics 2016-08-17 Erick J. Guerra , Ruth A. Daly

We model the evolution of active galactic nuclei by constructing their radio luminosity functions. We use a set of surveys of varying area and depth, namely the deep COSMOS survey of $1,916$ AGN sources, the wide shallow 3CRR, 7C and 6CE…

Astrophysics of Galaxies · Physics 2023-12-25 B. Šlaus , V. Smolcic , Ž. Ivezic , S. Fotopoulou , C. J. Willott , P. Pendo , C. Vignali , L. Chiappetti , M. Pierre

Extragalactic radio sources have been classified into two classes, Fanaroff-Riley I and II, which differ in morphology and radio power. Strongly emitting sources belong to the edge-brightened FR II class, and weakly emitting sources to the…

High Energy Astrophysical Phenomena · Physics 2016-12-07 S. Massaglia , G. Bodo , P. Rossi , S. Capetti , A. Mignone

Fast Radio Bursts (FRBs) are a promising tool for studying the low-density universe as their dispersion measures (DM) are extremely sensitive probes of electron column density. Active Galactic Nuclei (AGN) inject energy into the…

Astrophysics of Galaxies · Physics 2022-03-14 Adam J. Batten , Alan R. Duffy , Chris Flynn , Vivek Gupta , Emma Ryan-Weber , Nastasha Wijers

GPS sources are the objects of choice to study the initial evolution of extragalactic radio sources, since it is most likely that they are the young counterparts of large scale radio sources. Correlations found between their peak frequency,…

We present a comparison of radio observations of the archetypal powerful radio galaxy Cygnus A and 2-D numerical hydrodynamical simulations. We characterize some global trends in the observed radio properties and compare them with the…

Astrophysics · Physics 2009-11-10 J. C. Carvalho , R. A. Daly , M. P. Mory , C. P. O'Dea

We present a study of variability time scales in a large sample of Active Galactic Nuclei at several frequencies between 4.8 and 230 GHz. We investigate the differences of various AGN types and frequencies and correlate the measured time…

In the framework of hierarchical structure formation AGN feedback shapes the galaxy luminosity function. Low luminosity, galaxy-scale double radio sources are ideal targets to investigate the interplay between AGN feedback and star…

Astrophysics of Galaxies · Physics 2015-06-18 Volker Heesen , Judith H. Croston , Jeremy J. Harwood , Martin J. Hardcastle , Ananda Hota

In this study we investigate 179 radio-IR galaxies drawn from a sample of spectroscopically-confirmed galaxies that are detected in radio and mid-infrared (MIR) in the redshift range of $0.55 \leq z \leq 1.30$ in the Observations of…

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

The existing theoretical framework for the energies stored in the synchrotron-emitting lobes of radio galaxies and quasars doesn't properly account for the curved spectral shape that many of them exhibit. We characterise these spectra using…

Astrophysics of Galaxies · Physics 2015-06-03 Peter Duffy , Katherine M. Blundell

After a brief introduction to the morphological properties of FRI radio sources, we discuss the possibility that FRI jets are relativistic at their bases and decelerate quickly to non-relativistic velocities. From two-frequency data we…

Astrophysics · Physics 2009-10-31 P. Parma , M. Murgia , H. R. de Ruiter , R. Fanti

The enormous sizes and variability of emission of radio-loud AGNs arise from the relativistic flows of plasma along two oppositely directed jets. We use the Athena hydrodynamics code to simulate an extensive suite of 54 propagating…

Astrophysics of Galaxies · Physics 2018-12-19 Yutong Li , Paul J. Wiita , Terance Schuh , Geena Elghossain , Shaoming Hu

There is increasing evidence to suggest that AGN activity may be episodic, with a wide range of possible time scales. Radio galaxies exhibit the most striking examples of episodic activity, with two or three distinct pairs of lobes on…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 D. J. Saikia , M. Jamrozy , C. Konar , S. Nandi

We have developed an economical, effective numerical scheme for cosmic-ray transport suitable for treatment of electrons up to a few hundreds of GeV in multidimensional simulations of radio galaxies. The method follows the electron…

Astrophysics · Physics 2009-10-31 T. W. Jones , I. L. Tregillis , Dongsu Ryu

Active galactic nuclei (AGN) at the centres of galaxies can cycle between periods of activity and of quiescence. Characterising the duty-cycle of AGN is crucial for understanding their impact on the evolution of the host galaxy. For radio…

Active Galactic Nuclei (AGN) are ideal sources for multi-wavelength studies as their emission can cover almost 20 orders of magnitude in frequency from the radio to the gamma-ray band. After reviewing their basic properties, I will assess…

Astrophysics · Physics 2007-05-23 Paolo Padovani

Large-scale cosmological simulations suggest that feedback from active galactic nuclei (AGN) plays a crucial role in galaxy evolution. In this study, we directly test this hypothesis utilising SDSS spectra of a sample of 48 low redshift…

Astrophysics of Galaxies · Physics 2024-09-25 Patricia S. Bessiere , Cristina Ramos Almeida , Luke R. Holden , Clive N. Tadhunter , Gabriela Canalizo

The dominant source of radio continuum emissions at low frequencies is synchrotron radiation, which originates from star-forming regions in disk galaxies and from powerful jets produced by active galactic nuclei (AGN). We studied the Bootes…

Astrophysics of Galaxies · Physics 2023-08-22 Akriti Sinha , Abhirup Datta