English
Related papers

Related papers: High Frequency Peakers

200 papers

Radio sources with peaked spectra (peaked spectrum sources, PSS) and compact symmetric objects (CSO) are powerful, compact, and presumably young AGNs and therefore particularly suitable to study aspects of the AGN-host connection. We use a…

Astrophysics of Galaxies · Physics 2023-11-28 H. Meusinger , M. Mhaskey

We report first X-ray Chandra observations of a sample of seven low luminosity compact (LLC) sources. They belong to a class of young compact steep spectrum (CSS) radio sources. Four of them have been detected, the other three have upper…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 M. Kunert-Bajraszewska , A. Labiano , A. Siemiginowska , M. Guainazzi

Young radio-loud active galactic nuclei form an important tool to investigate the evolution of extragalactic radio sources. To study the early phases of expanding radio sources, we have constructed CORALZ, a sample of 25 compact…

Astrophysics of Galaxies · Physics 2015-05-13 N. de Vries , I. A. G. Snellen , R. T. Schilizzi , K. -H. Mack , C. R. Kaiser

We present Very Large Array observations at 1.4 and 5 GHz of a sample of 16 quasi-stellar objects (QSOs) at z = 1.78 to 2.71. Half of the chosen quasars are bright at mm wavelengths (250 or 350 GHz) while the other half were not detected at…

Astrophysics · Physics 2008-11-26 A. Petric , C. L. Carilli , F. Bertoldi , A. Beelen , P. Cox , A. Omont

A relativistic radio component, which moves in a direction close to the sky plane, will increase in flux density when it decelerates. This effect is the basis for the qualitative model for GPS galaxies we present in this paper, which can…

Astrophysics · Physics 2007-05-23 I. A. G. Snellen , R. T. Schilizzi , A. G. de Bruyn , G. K. Miley

We have observed a small sample of powerful double radio sources (radio galaxies and quasars) at frequencies around 90 GHz with the BIMA millimetre array, with the intention of constraining the resolved high-frequency spectra of radio…

Astrophysics · Physics 2009-11-13 M. J. Hardcastle , L. W. Looney

This paper argues that repeating and apparently non-repeating Fast Radio Bursts are distinct classes of events produced by distinct classes of sources. I review the evidence for that division, and then discusses the statistics of these…

High Energy Astrophysical Phenomena · Physics 2024-09-12 J. I. Katz

We present intermediate resolution, wide wavelength coverage spectra for a complete sample of 14 compact radio sources taken with the aim of investigating the impact of the nuclear activity on the circumnuclear (ISM) in the early stages of…

Astrophysics · Physics 2009-11-13 J. Holt , C. N. Tadhunter , R. Morganti

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

We present high-resolution radio observations of a sample of 65 radio sources at low Galactic latitudes. The sources were all observed at 5 GHz with the Very Large Array A-array. MERLIN observations at 5 GHz of the ultracompact HII region…

Astrophysics · Physics 2009-11-10 D. J. Saikia , P. Thomasson , S. Roy , A. Pedlar , T. W. B. Muxlow

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

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

We present four Mpc-sized radio galaxies which consist of a pair of double-lobed radio sources, aligned along the same axis, and with a coinciding radio core. We have called these peculiar radio sources `double-double' radio galaxies (DDRG)…

Knowledge of the population of radio sources in the range ~2-200 GHz is important for understanding their effects on measurements of the Cosmic Microwave Background power spectrum. We report measurements of the 30 GHz flux densities of 605…

Characterising spectral variability of radio sources is a technique that offers the ability to determine the astrophysics of the intervening media, source structure, emission and absorption processes. We present broadband (0.072--10 GHz)…

Astrophysics of Galaxies · Physics 2022-04-06 K. Ross , N. Hurley-Walker , N. Seymour , J. R. Callingham , T. J. Galvin , M. Johnston-Hollitt

From an on-going survey of the Galactic bulge, we have discovered a number of compact, steep spectrum radio sources. In this present study we have carried out more detailed observations for two of these sources, located 43 arcmin and 12.7…

High Energy Astrophysical Phenomena · Physics 2021-07-21 S. D. Hyman , D. A. Frail , J. S. Deneva , N. E. Kassim , S. Giacintucci , J. E. Kooi , T. J. W. Lazio , I. Joyner , W. M. Peters , V. Gajjar , A. P. V. Siemion

We discuss our current understanding of the nature of the faint, high-frequency radio sky. The Tenth Cambridge (10C) survey at 15.7 GHz is the deepest high-frequency radio survey to date, covering 12 square degrees to a completeness limit…

Astrophysics of Galaxies · Physics 2016-03-01 Imogen H. Whittam , Julia M. Riley , David A. Green , Matt J. Jarvis

A search for HI absorption has been made in 23 radio galaxies using the ATCA, the VLA and the WSRT. In five galaxies HI absorption was detected. We investigate how the detection rate is distributed among galaxies with different radio and…

Astrophysics · Physics 2009-10-31 R. Morganti , T. A. Oosterloo , C. N. Tadhunter , G. van Moorsel , N. Killeen , K. A. Wills

Green Peas (GPs) are young, compact, star-forming dwarf galaxies, and local (z~0.3) analogues of the early galaxies (z>6) considered to be mainly responsible for the reionisation of the Universe. Recent X-ray observations of GPs have…

[Abridged] Physical and evolutionary properties of the sub-mJy radio population are not entirely known. The radio/optical analysis of the ATESP 5 GHz sample has revealed a significant class of compact flat/inverted radio-spectrum sources…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 I. Prandoni , H. R. de Ruiter , R. Ricci , P. Parma , L. Gregorini , R. D. Ekers