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Related papers: Small and young radio sources

200 papers

We have explored, in the general framework of the ``young source'' scenario, evolutionary models for GHz Peaked Spectrum (GPS) galaxies and quasars which reproduce the observed counts, redshift and peak frequency distributions of currently…

Astrophysics · Physics 2007-05-23 G. De Zotti , G. L. Granato , L. Silva , D. Maino , L. Danese

According to a generally accepted paradigm, small intrinsic sizes of Compact Steep Spectrum (CSS) radio sources are a direct consequence of their youth, but in later stages of their evolution they are believed to become large-scale sources.…

Astrophysics · Physics 2009-11-13 Andrzej Marecki , Magdalena Kunert-Bajraszewska , Ralph E. Spencer

Aims: The ``bright'' High Frequency Peakers (HFPs) sample is a mixture of blazars and intrinsically small and young radio sources. We investigate the polarimetric characteristics of 45 High Frequency Peakers, from the ``bright'' HFP sample,…

Astrophysics · Physics 2009-11-13 M. Orienti , D. Dallacasa

Context. The majority of bright extragalactic gamma-ray sources are blazars. Only a few radio galaxies have been detected by Fermi/LAT. Recently, the GHz-peaked spectrum source PKS 1718-649 was confirmed to be gamma-ray bright, providing…

High Energy Astrophysical Phenomena · Physics 2016-09-28 C. Müller , P. R. Burd , R. Schulz , R. Coppejans , H. Falcke , H. Intema , M. Kadler , F. Krauß , R. Ojha

GPS and CSS radio sources are the objects of choice to investigate the evolution of young radio-loud AGN. Previous investigations, mainly based on number counts and source size distributions, indicate that GPS/CSS sources decrease…

Astrophysics · Physics 2009-11-07 I. A. G. Snellen , K. -H. Mack , R. T. Schilizzi , W. Tschager

Gigahertz-Peaked Spectrum (GPS) sources are probably the precursors of local radio galaxies.Existing GPS source samples are small (<200). It is necessary to extend the availabe sample of the Gigahertz-Peaked Spectrum (GPS) and High…

Astrophysics · Physics 2009-11-13 B. Vollmer , T. P. Krichbaum , E. Angelakis , Y. Y. Kovalev

We are entering a new era of sensitive, large-area and multi-frequency radio surveys that will allow us to identify Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources over a wide range in radio luminosity and…

Astrophysics of Galaxies · Physics 2016-03-16 Elaine M. Sadler

Up till now very few dying sources were known, presumably because the dying phase is short at centimeter wavelengths. We therefore have tried to improve the statistics on sources that have ceased to be active, or are intermittently active.…

Astrophysics · Physics 2009-11-13 P. Parma , M. Murgia , H. R. de Ruiter , R. Fanti , K. -H. Mack , F. Govoni

Based on the FIRST and SDSS catalogues a flux density limited sample of weak Compact Steep Spectrum (CSS) sources with radio luminosity below 10^26 [W/Hz] at 1.4 GHz has been constructed. Our previous multifrequency observations of CSS…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-11 Magdalena Kunert-Bajraszewska , Peter Thomasson

We present a new sample of Compact Steep Spectrum (CSS) sources with radio luminosity below 10^26 W/Hz at 1.4 GHz called the low luminosity compact (LLC) objects. The sources have been selected from FIRST survey and observed with MERLIN at…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 M. Kunert-Bajraszewska , M. P. Gawronski , A. Labiano , A. Siemiginowska

Recent studies have shown that both 21cm HI absorption and soft X-ray absorption serve as excellent tracers of the dense and dusty gas near the active nucleus of young radio galaxies, offering new insight into the physical nature of the…

Astrophysics of Galaxies · Physics 2022-01-05 Emily F. Kerrison , Vanessa A. Moss , Elaine M. Sadler , James R. Allison

We define a complete sample of thirty-three GHz-Peaked-Spectrum (GPS) radio sources based on their spectral properties. We present measurements of the radio spectra and polarization of the complete sample and a list of additional GPS…

Astrophysics · Physics 2016-08-30 C. Stanghellini , C. P. O'Dea , D. Dallacasa , S. A. Baum , R. Fanti , C. Fanti

We consider the high radio frequency (15 GHz - 353 GHz) properties and variability of 35 Brightest Cluster Galaxies (BCGs). These are the most core-dominated sources drawn from a parent sample of more than 700 X-ray selected clusters, thus…

Multifrequency radio continuum observations (1.4-22 GHz) of a sample of reddened QSOs are presented. We find a high incidence (13/16) of radio spectral properties, such as low frequency turnovers, high frequency spectral breaks or steep…

High Energy Astrophysical Phenomena · Physics 2012-01-20 A. Georgakakis , M. Grossi , J. Afonso , A. M. Hopkins

M17 JVLA 35 is a radio source detected in projection against the M17 HII region. In recent observations, its spectrum between 4.96 and 8.46 GHz was found to be positive and very steep, with $\alpha \geq 2.9 \pm 0.6$ ($S_\nu \propto…

Astrophysics of Galaxies · Physics 2015-06-22 L. F. Rodriguez , C. Carrasco-Gonzalez , G. Montes , M. Tapia

Spectral variability of radio sources encodes information about the conditions of intervening media, source structure, and emission processes. With new low-frequency radio interferometers observing over wide fractional bandwidths, studies…

Astrophysics of Galaxies · Physics 2020-12-23 K. Ross , J. R. Callingham , N. Hurley-Walker , N. Seymour , P. Hancock , T. M. O. Franzen , J. Morgan , S. V. White , M. E. Bell , P. Patil

Radio galaxies with a projected linear size > 1 Mpc are classified as giant radio sources. According to the current interpretation these are old sources which have evolved in a low-density ambient medium. Since radiative losses are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 E. Orrù , M. Murgia , L. Feretti , F. Govoni , G. Giovannini , W. Lane , N. Kassim , R. Paladino

Global VLBI observations at 5 GHz have been performed to study the source morphology in 10 compact steep-spectrum (CSS) sources selected from the Peacock & Wall catalogue with the aim of finding asymmetric structures produced by the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 D. Dallacasa , M. Orienti , C. Fanti , R. Fanti , C. Stanghellini

We present XMM-Newton observations of a complete sample of five archetypal young radio-loud AGN, also known Gigahertz Peaked Spectrum (GPS) sources. They are among the brightest and best studied GPS/CSO sources in the sky, with radio powers…

Astrophysics · Physics 2009-11-11 Jacco Vink , Ignas Snellen , Karl-Heinz Mack , Richard Schilizzi

Gigahertz Peaked Spectrum (GPS) radio galaxies are generally thought to be the young counterparts of classical extended radio sources and live in massive ellipticals. GPS sources are vital for studying the early evolution of radio-loud AGN,…

Astrophysics · Physics 2009-11-13 N. de Vries , I. A. G. Snellen , R. T. Schilizzi , M. D. Lehnert , M. N. Bremer