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Related papers: Constraining the evolution of young radio-loud AGN

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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

We discovered an X-ray cluster in a recent pointed Chandra observation of the radio-loud compact-steep-spectrum source 1321+045 at the redshift of 0.263. 1321+045 is part of larger survey which aims to study the X-rays properties of weak…

Astrophysics of Galaxies · Physics 2013-11-18 Maciej Ceglowski , Magdalena Kunert-Bajraszewska , A. Siemiginowska , A. Labiano , M. Guainazzi

The vast majority of extragalactic compact continuum radio sources are associated with star formation or jets from (super)massive black holes and, as such, are more likely to be found in association with starburst galaxies or early-type…

High Energy Astrophysical Phenomena · Physics 2023-12-20 D. Vohl , H. K. Vedantham , J. W. T. Hessels , C. G. Bassa , D. O. Cook , D. L. Kaplan , T. W. Shimwell , C. Zhang

We positionally match the 6 cm GB6, 20 cm FIRST and NVSS, and 92 cm WENSS radio catalogs and find 16,500 matches in ~3,000 deg2 of sky. Using this unified radio database, we construct radio "color-magnitude-morphology" diagrams and find…

We report the results of multifrequency-VLBI observations of GHz-Peaked-Spectrum (GPS) radio sources. The VLBI structure and component spectra of some GPS sources are presented. Our VLBI results show that about 80% of the GPS galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-20 X. Liu , H. -G Song , L. Cui

In the past decade, high sensitivity radio surveys have revealed that the local radio AGN population is dominated by moderate-to-low power sources with emission that is compact on galaxy scales. High-excitation radio galaxies (HERGs) with…

Astrophysics of Galaxies · Physics 2020-03-04 Jonathon C. S. Pierce , Clive N. Tadhunter , Raffaella Morganti

The faint radio-source population includes sources dominated both by star formation and active galactic nuclei (AGN), encoding the evolution of activity in the Universe. To investigate its nature, we probabilistically classified 4,471 radio…

Extended radio emission detected around a sample of GHz Peaked Spectrum (GPS) radio sources is discussed. Evidence for extended emission which is related to the GPS source is found in 6 objects out of 33. Three objects are associated with…

Astrophysics · Physics 2009-11-11 C. Stanghellini , C. P. O'Dea , D. Dallacasa , P. Cassaro , S. A. Baum , R. Fanti , C. Fanti

We use highly spectroscopically complete observations of the radio sources from the VLA 1.4 GHz survey of the HDF-N region to study the faint radio galaxy population and its evolution. We spectrally classify the sources into four spectral…

Astrophysics · Physics 2011-02-11 A. J. Barger , L. L. Cowie , W. -H. Wang

They are weak, they are small, and they are often overlooked, but they are numerous and an ubiquitous sign of accreting black holes: compact radio cores and jets in low-power AGN. Here I summarize our work concerning these radio cores and…

Astrophysics · Physics 2007-05-23 Heino Falcke

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

In this paper we analyse whether `giant' radio galaxies (GRGs) differ from `normal'-size galaxies (NSGs) except for the linear extent of their radio structure. We compare a number of properties of GRGs with the corresponding properties of…

Astrophysics · Physics 2009-11-11 J. Machalski , M. Jamrozy

Kinematic and spectral studies are improving our knowledge of the age distribution in compact radio sources, providing evidence that small sources are generally very young. The properties of jets in objects spanning the size range from a…

Astrophysics · Physics 2007-07-25 M. Giroletti

Following previous work, we further confirm that the cosmic evolution of steep-spectrum radio-loud AGNs (active galactic nuclei) can be reproduced by a simple combination of density evolution (DE) and luminosity evolution (LE). This mixture…

High Energy Astrophysical Phenomena · Physics 2018-10-31 Zunli Yuan , Jiancheng Wang , Ming Zhou , Longhua Qin , Jirong Mao

This paper analyses the radio properties of a subsample of optically obscured (R>25.5) galaxies observed at 24um by the Spitzer Space Telescope within the First Look Survey. 96 F[24um]>0.35 mJy objects out of 510 are found to have a radio…

Astrophysics · Physics 2009-11-13 M. Magliocchetti , P. Andreani , M. A. Zwaan

At bright radio powers ($P_{\rm 1.4 GHz} > 10^{25}$ W/Hz) the space density of the most powerful sources peaks at higher redshift than that of their weaker counterparts. This paper establishes whether this luminosity-dependent evolution…

Astrophysics of Galaxies · Physics 2015-09-16 E. E. Rigby , J. Argyle , P. N. Best , D. Rosario , H. J. A. Röttgering

We present a study of the extended radio emission in a sample of 8434 low redshift (z < 0.35) broad line active galactic nuclei (AGN) from the Sloan Digital Sky Survey (SDSS). To calculate the jet and lobe contributions to the total radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Stephen E. Rafter , D. Michael Crenshaw , Paul J. Wiita

We combine deep optical and radio data, from the Hyper Suprime-Cam and the Low-Frequency Array (LOFAR) respectively, to study 78 radio AGN in nearby (z<0.5) dwarf galaxies. Comparison to a control sample, matched in stellar mass and…

Astrophysics of Galaxies · Physics 2022-02-16 F. Davis , S. Kaviraj , M. J. Hardcastle , G. Martin , R. A. Jackson , K. Kraljic , K. Malek , S. Peirani , D. J. B. Smith , M. Volonteri , L. Wang

We discuss the properties of compact nuclear radio components in Seyfert galaxies from the extended 12-micron AGN sample of Rush et al.(1993). Our main results can be summarised as follows. Type 1 and type 2 Seyferts produce compact radio…

Astrophysics · Physics 2009-11-06 Andy Thean , Alan Pedlar , Marek J. Kukula , Stefi A. Baum , Christopher P. O'Dea

The study on the dynamic evolution of young supernova remnants (SNRs) is an important way to understand the density structure of the progenitor's circumstellar medium. We have reported the acceleration or deceleration, proper motion and…

Astrophysics of Galaxies · Physics 2022-12-14 Xianhuan Lei , Hui Zhu , Haiyan Zhang , Wenwu Tian
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