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Related papers: Identifying Compact Symmetric Objects from the VLB…

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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

We present VLBA observations at 15 GHz of ten GHz Peaked Spectrum (GPS) radio sources. The cores are often difficult or impossible to locate. When likely cores are found, they account for a small fraction of the flux density in GPS galaxies…

Astrophysics · Physics 2009-11-07 C. Stanghellini , D. Dallacasa , C. P. O'Dea , S. A. Baum , R. Fanti , C. Fanti

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

We defined a sub-sample of twelve GPS sources which have not been observed with the VLBI before, from the Parkes half-Jansky sample, and carried out VLBI observations at 1.6 GHz and 5 GHz with the European VLBI Network (EVN) in 2006 and…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-25 L. Cui , X. Liu , J. Liu , H. -G. Song , Z. Ding

This paper addresses, for the first time, a key aspect of the phenomenology of Compact Symmetric Objects (CSOs) -- the characteristics of their radio spectra. We present a radio-spectrum description of a complete sample of high luminosity…

Among radio galaxies, compact sources are a class of objects not yet well understood, and most of them cannot be included in classical populations of compact radio sources (flat spectrum AGN or compact steep spectrum sources). Our main goal…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 E. Liuzzo , S. Buttiglione , G. Giovannini , M. Giroletti , S. Capetti , G. B. Taylor

Compact steep-spectrum (CSS) and peaked spectrum (PS) radio sources are compact, powerful radio sources. The multi-frequency observational properties and current theories are reviewed with emphasis on developments since the earlier review…

Astrophysics of Galaxies · Physics 2021-04-07 Christopher P. O'Dea , D. J. Saikia

We have obtained 8.4 GHz VLBA observations of a 31-GHz complete sample of ~100 sources between 10 and 100 mJy. The main goals of these observations are: to determine the angular size, radio spectra and identification for a weak sample of…

Astrophysics · Physics 2008-06-19 W. A. Majid , E. B. Fomalont , D. S. Bagri

We present the results of multi-epoch global VLBI observations of the Compact Symmetric Object (CSO), 0710+439 at 5 GHz. Analysis of data spread over 13 years shows strong evidence for an increase in the separation of the outer components…

Astrophysics · Physics 2007-05-23 Izabela Owsianik , John E. Conway

Compact symmetric objects (CSOs) are thought to be short-lived radio sources with two lobes of emission that are separated by less than a kpc in projection. However, studies of such systems at high redshift is challenging due to the limited…

Astrophysics of Galaxies · Physics 2025-10-10 J. P. McKean , C. Spingola , D. M. Powell , S. Vegetti

Compact Symmetric Objects (CSOs) are a distinct category of jetted active galactic nuclei whose high-energy emission is not well understood. We examined the X-ray characteristics of 17 bona fide CSOs using observations from Chandra,…

High Energy Astrophysical Phenomena · Physics 2025-01-22 Subhashree Swain , C. S. Stalin , Vaidehi S. Paliya , D. J. Saikia

The evolution of symmetric extragalactic radio sources can be characterized by four distinct growth stages of the radio luminosity versus size of the source. The interaction of the jet with the ambient medium results in the formation and…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-09 Tao An , Willem A. Baan

VLBA observations at 18 cm are presented for 28 Compact Steep-spectrum radio Sources (CSSs) from the B3-VLA CSS sample. These sources were unresolved in previous VLA observations at high frequencies or their brightness distribution was…

Astrophysics · Physics 2009-11-07 D. Dallacasa , S. Tinti , C. Fanti , R. Fanti , L. Gregorini , C. Stanghellini , M. Vigotti

We present a new sample of 30 nearby (z<0.2) BL Lacs, selected to study the nuclear as well as the large scale properties of low power radio sources. In this first paper, we show and discuss new radio data taken with the VLA (19 objects at…

Astrophysics · Physics 2009-11-10 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

We investigate the sample of 213 GPS sources selected from simultaneous multi-frequency 1-22 GHz observations obtained with RATAN-600 radio telescope. We use publicly available data to characterize parsec-scale structure of the selected…

Astrophysics of Galaxies · Physics 2009-01-23 K. V. Sokolovsky , Y. Y. Kovalev

Aims - We report new Very Large Array polarimetric observations of Compact Steep-Spectrum (CSS) sources at 8.4, 15, and 23GHz. Methods - Using multi-frequency VLA observations we have derived sub-arcsecond resolution images of the total…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 F. Mantovani , A. Rossetti , W. Junor , D. J. Saikia , C. J. Salter

Context: The Deep Extragalactic VLBI-Optical Survey (DEVOS) aims at constructing a large sample of compact radio sources up to two orders of magnitude fainter than those studied in other Very Long Baseline Interferometry (VLBI) surveys.…

Astrophysics · Physics 2008-01-09 S. Frey , L. I. Gurvits , Z. Paragi , L. Mosoni , M. A. Garrett , S. T. Garrington

A short overview is given of the status of research on young extragalactic radio sources. We concentrate on Very Long Baseline Interferometric (VLBI), and space-VLBI results obtained with the VLBI Space Observatory Programme (VSOP). In…

Astrophysics · Physics 2008-02-15 I. A. G. Snellen

Broad absorption line quasars (BAL QSOs) belong to a class of objects not well-understood as yet. Their UV spectra show BALs in the blue wings of the UV resonance lines, owing to ionized gas with outflow velocities up to 0.2 c. They can…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-17 G. Bruni , D. Dallacasa , K. -H. Mack , F. M. Montenegro-Montes , J. I. González-Serrano , J. Holt , F. Jiménez-Luján

Data from a recent Australia Telescope Compact Array (ATCA) program of multi-frequency, multi-epoch monitoring of 202 active galactic nuclei with declinations < +10 degrees have been searched for GHz Peaked Spectrum (GPS) and Compact Steep…

Astrophysics · Physics 2009-11-10 P. G. Edwards , S. J. Tingay