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The constructive and destructive interference in different layers of the James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) detector arrays modulate the detected signal as a function of wavelength. Additionally, sources of…

The mJy variable extragalactic radio sky is known to be broadly non-changing with approximately $3\%$ of persistent radio sources exhibiting variability which is largely AGN-related. In the faint (<mJy) flux density regime, it is widely…

A Double-Double Radio Galaxy (DDRG) is defined as consisting of a pair of double radio sources with a common centre. In this paper we present an analytical model in which the peculiar radio structure of DDRGs is caused by an interruption of…

Astrophysics · Physics 2009-10-31 Christian R. Kaiser , A. P. Schoenmakers , H. J. A. Rottgering

We present a multi-wavelength study into the nature of faint radio sources in a deep radio image with the Giant Meterwave Radio Telescope at 612\,MHz covering 1.2 deg$^2$ of the ELAIS N1 region. We detect 2800 sources above…

Astrophysics of Galaxies · Physics 2017-04-12 E. F. Ocran , A. R. Taylor , M. Vaccari , D. A. Green

Bent-double radio sources have been used as a probe to measure the density of intergalactic gas in galaxy groups. We carry out a series of high-resolution, 3D simulations of AGN jets moving through an external medium with a constant density…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Brian J. Morsony , Jacob J. Miller , Sebastian Heinz , Emily Freeland , Eric Wilcots , Marcus Brueggen , Mateusz Ruszkowski

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

Before we have determined that giant radio structure is typical for steep-spectrum sources detected with Ukrainian T-shaped Radio Telescope of model 2 (UTR-2). To estimate the jet propagation velocity and environment density of giant radio…

Astrophysics of Galaxies · Physics 2019-06-05 Alla Miroshnichenko

This work studies the correlation among environmental density and radio AGN presence up to $z = 2$. Using data from the photometric COSMOS survey and its radio 1.4 GHz follow-up (VLA-COSMOS), a sample of radio AGNs has been defined. The…

Astrophysics of Galaxies · Physics 2016-09-09 Nicola Malavasi , Sandro Bardelli , Paolo Ciliegi , Olivier Ilbert , Lucia Pozzetti , Elena Zucca

I summarize Xray properties of high redshift radio galaxies, beginning with a brief review of what has been learned from Xray observations of low redshift powerful radio galaxies (in particular, Cygnus A), and then turning to Chandra…

Astrophysics · Physics 2009-11-07 C. L. Carilli

Radio-loud active galaxies (RLAGN) can exhibit various morphologies. The Fanaroff-Riley (FR) classifications, which are defined by the locations of peaks in surface brightness, have been applied to many catalogues of RLAGN. The FR…

We present results of a numerical integration of the hydrodynamical equations governing the self-similar, two-dimensional gas flow behind the bow shock of an FRII radio source embedded in an IGM with a power law density profile. The model…

Astrophysics · Physics 2009-10-31 Christian R. Kaiser , Paul Alexander

Relativistic jets originating at the center of AGN are embedded in extreme environments with strong magnetic fields and high particle densities, which makes them a fundamental tool for studying the physics of magnetized plasmas. We aim to…

High Energy Astrophysical Phenomena · Physics 2025-06-04 V. Bartolini , D. Dallacasa , J. L. Gómez , M. Giroletti , R. Lico , J. D. Livingston

Fanaroff-Riley class I (FRI) radio galaxies show centre-brightened emission from disrupted lower power jets, while traditionally more luminous class II (FRIIs), are edge-brightened, with relativistic jets terminating in hotspots. Population…

Astrophysics of Galaxies · Physics 2026-05-11 B. Barkus , J. H. Croston , B. Mingo , M. J. Hardcastle , G. Gürkan , V. H. Mahatma

We focus on a comparison of the space densities of FRI and FRII extended radio sources at different epochs, and find that FRI and FRII sources show similar space density enhancements in various redshift ranges, possibly implying a common…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Melanie A. Gendre , Jasper V. Wall , Philip N. Best

This is the second in a series of papers presenting an analytical model for the evolution of FRII radio sources. In this paper we evaluate the expected radio emission from a radio source incorporating energy loss processes for the…

Astrophysics · Physics 2015-06-24 Christian R. Kaiser , Jane Dennett-Thorpe , Paul Alexander

Giant radio sources, including galaxies and quasars (hereafter GRGs), are active galactic nuclei (AGN) hosting relativistic jets with source sizes exceeding the projected length of 0.7 Mpc. They are crucial to understanding the evolution of…

High Energy Astrophysical Phenomena · Physics 2025-07-08 Vaidehi S. Paliya , D. J. Saikia , Gabriele Bruni , Alberto Dominguez , C. S. Stalin

Many of the powerful radio galaxies observed at high redshift are very small, presumably because they are very young. A simple model, which treats the radio source as a bubble expanding into a radially stratified medium, is capable of…

Astrophysics · Physics 2007-05-23 Mitchell C. Begelman

I present four-frequency radio observations of the wide-angle tail radio galaxy 3C130. By a technique of simulated observations, I assess the systematic errors in the data due to the varying uv plane coverage in the different observations…

Astrophysics · Physics 2007-05-23 M. J. Hardcastle

A comprehensive search for variable and transient radio sources has been conducted using ~55,000 snapshot images of the FIRST survey. We present an analysis leading to the discovery of 1,627 variable and transient objects down to mJy levels…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Nithyanandan Thyagarajan , David J. Helfand , Richard L. White , Robert H. Becker

Previous analyses of the space densities of extragalactic radio sources have proceeded on the assumption of two populations: flat-spectrum and steep-spectrum objects, compact and extended in radio structure respectively. It is now generally…

Astrophysics · Physics 2007-05-23 C A Jackson