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Related papers: Intermittent radio galaxies and source statistics

200 papers

The study of both neutral and ionized gas in young radio sources is providing key information on the effect the radio plasma has on the ISM of these objects. We present results obtained for the compact radio sources PKS1549-79, 4C12.50 and…

Astrophysics · Physics 2009-11-07 R. Morganti , C. Tadhunter , T. Oosterloo , J. Holt , A. Tzioumis , K. Wills

This paper describes an investigation of the early evolution of extragalactic radio sources using samples of faint and bright Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio galaxies. Correlations found between their…

We have used VLBA fringe visibility data obtained at 15 GHz to examine the compact structure in 250 extragalactic radio sources. For 171 sources in our sample, more than half of the total flux density seen by the VLBA remains unresolved on…

We present first results from a new, multiyear, time domain survey of young stars in the North America Nebula complex using the Palomar Transient Factory. Our survey is providing an unprecedented view of aperiodic variability in young stars…

Solar and Stellar Astrophysics · Physics 2026-04-01 Krzysztof Findeisen , Lynne Hillenbrand , Eran Ofek , David Levitan , Branimir Sesar , Russ Laher , Jason Surace

The relation between parameters the D/sqrt(I) and Ic/Isum and radiation patterns of the optical and radio components of an extended radio source is analyzed, where D and I are the apparent size and observed radiation intensity of the source…

Astrophysics of Galaxies · Physics 2016-12-21 V. R. Amirkhanyan

In a growing number of galaxy clusters diffuse extended radio sources have been found. These sources are not directly associated with individual cluster galaxies. The radio emission reveal the presence of cosmic rays and magnetic fields in…

High Energy Astrophysical Phenomena · Physics 2019-02-13 R. J. van Weeren , F. de Gasperin , H. Akamatsu , M. Brüggen , L. Feretti , H. Kang , A. Stroe , F. Zandanel

We make a new estimate of the extragalactic radio background down to kHz frequencies based on the observed luminosity functions and radio spectra of normal galaxies and radio galaxies. We have constructed models for the spectra of these two…

Astrophysics · Physics 2010-11-30 R. J. Protheroe , P. L. Biermann

As a part of the ISOPHOT CIRB (Cosmic Infrared Background Radiation) project we have searched for point-like sources in eight fields mapped at two or three wavelengths between 90 and 180um. Most sources are previously unknown and based on…

Astrophysics · Physics 2007-05-23 M. Juvela , K. Mattila , D. Lemke

We present the analysis of serendipitous sources in a deep, 500 ksec, hard X-ray observation of the Coma cluster region with the IBIS instrument onboard INTEGRAL. In addition to the Coma cluster, the final 20-50 keV image contains 12…

Astrophysics · Physics 2009-11-10 R. Krivonos , A. Vikhlinin , E. Churazov , A. Lutovinov , S. Molkov , R. Sunyaev

We estimate ages and physical properties of powerful radio galaxies. An analysis of new multi-wavelength VLA observations of eleven very powerful classical double (FRIIb) radio galaxies with redshifts between 0.4 and 1.3 is presented. We…

Transient astronomical sources are typically powered by compact objects and usually signify highly explosive or dynamic events. While radio astronomy has an impressive record of obtaining high time resolution observations, usually it is…

Astrophysics · Physics 2009-11-10 S. D. Hyman , T. J. W. Lazio , N. E. Kassim , P. S. Ray , C. B. Markwardt , F. Yusef-Zadeh

Over a decade ago it was established that the remarkable high energy transients, known as soft gamma-ray repeaters (SGRs), are a Galactic population and originate from neutron stars with intense (<~ 10^15 G) magnetic fields ("magnetars").…

We present 1 - 12 GHz Karl G. Jansky Very Large Array observations of 9 off-nuclear persistent radio sources (PRSs) in nearby (z < 0.055) dwarf galaxies, along with high-resolution European very-long baseline interferometry (VLBI) Network…

Fast (~1000 km/s) outflows of neutral gas (from 21-cm HI absorption) are detected in strong radio sources. The outflows occur, at least in some cases, at distances from the radio core that range between few hundred parsecs and kpc. These HI…

Astrophysics · Physics 2007-05-23 Raffaella Morganti , Clive Tadhunter , Tom Oosterloo , Joanna Holt , Bjorn Emonts

We consider the effects of radio-wave scattering by cool ionized clumps ($T\sim 10^4\,$K) in circumgalactic media (CGM). The existence of such clumps are inferred from intervening quasar absorption systems, but have long been something of a…

Astrophysics of Galaxies · Physics 2018-12-19 H. K. Vedantham , E. S. Phinney

Radio sources with steep and ultra-steep spectra, identified through a series of surveys of the Cold experiment using the RATAN-600 radio telescope, formed the basis of the Big Trio program aimed at discovering distant radio galaxies. With…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-02 Olga Zhelenkova , Adelina Temirova , Yurij Parijskij , Natalia Soboleva

Nonlinear radio waves modulate the plasma, scatter on the modulations, and develop an intermittent power spectrum -- perhaps. Rudiments of theory, numerical simulations, and qualitative modeling of nonlinear scattering are presented.…

High Energy Astrophysical Phenomena · Physics 2020-02-10 Andrei Gruzinov

We consider the incidence of HI absorption in intrinsically small sub-galactic sized extragalactic sources selected from sources classified as Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources. We find that the…

Astrophysics · Physics 2009-11-07 Y. M. Pihlstroem , J. E. Conway , R. C. Vermeulen

X-ray emission traces the gaseous environments of radio sources. The medium must be present for jet confinement, but what are its influence on jet fuelling, dynamics, propagation, and disruption? The observational situation is both…

Astrophysics · Physics 2009-10-31 D. M. Worrall

We summarize results from flux density monitoring campaigns performed with the 100 meter radio-telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties of the rapid variability from…

Astrophysics · Physics 2009-11-07 T. P. Krichbaum , A. Kraus , L. Fuhrmann , G. Cimo , A. Witzel