Compact Symmetric Objects and the Evolution of Powerful Extragalactic Radio Sources

Readhead, A. C. S.; Taylor, G. B.; Pearson, T. J.; Wilkinson, P. N.

doi:10.1086/176997

Cited by 248 publications

(239 citation statements)

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“…Such a conclusion is consistent with CSOs being orientated close to the plane of the sky and with their hotspot-core arm-length ratio being close to one (Readhead et al 1996). However the total source expansion could be also affected by interaction with the ISM.…”

Section: Introductionsupporting

confidence: 80%

Soon After the Birth of Radio Sources

Owsianik

Conway²,

Polatidis³

2001

Symp. - Int. Astron. Union

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Abstract.Compact Symmetric Objects (CSOs) represent an early stage in the life of radio galaxies. Our kinematic studies over a 20 year timebase have unambiguously demonstrated that they expand fast and that the radio activity is recently born. The CSO evolution with time is however still a matter of investigation. If they are progenitors of the "classical double" radio sources, then in order to fit the the observed statistics of radio sources, CSOs must have decrease their luminosity and expansion speed with time. It is also possible that CSOs represent a phase of periodic activity of the central engine; in this case the presence of the old activity in the form of extended weak emission, should be observed.

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Section: Introductionsupporting

confidence: 80%

Soon After the Birth of Radio Sources

Owsianik

Conway²,

Polatidis³

2001

Symp. - Int. Astron. Union

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“…The parametric solutions use a simplified assumption that the separation velocity of the hotspot remains constant during the early evolution Readhead et al 1996;Carvalho 1998;Kaiser & Alexander 1997). However, constant-velocity models may not be representative for observed source behavior.…”

Section: The Size and Velocity Of The Hot Spotsmentioning

confidence: 99%

The Dynamic Evolution of Young Extragalactic Radio Sources

Baan

2012

ApJ

204

241

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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 evolution of sources with non-standard (flaring) morphology. In addition, cessation or restarting of the jet power and obstruction of the jet will also result in distinct morphological structures. The radio source population may thus be classified in morphological types that indicate the prevailing physical processes. Compact symmetric objects (CSOs) occupy the earliest evolutionary phase of symmetric radio sources and their dynamical behavior is fundamental for any further evolution. Analysis of CSO dynamics is presented for a sample of 24 CSOs with known redshift and hotspot separation velocity and with a large range of radio power. Observables such as radio power, separation between two hotspots, hotspot separation velocity, and kinematic age of the source are found to be generally consistent with the self-similar predictions for individual sources that reflect the varying density structure of the ambient interstellar medium. Individual sources behave different from the group as a whole. The age and size statistics confirm that a large fraction of CSOs does not evolve into extended doubles.

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“…Evolutionary scenarios require that the radio luminosity of GPS sources decreases with evolution, not to exceed the number of observed FR II galaxies (Readhead et al 1996). Recently, Stawarz et al (2008) have proposed an evolutionary model for GPS sources, which explicitly predicts the dependency of the broadband Spectral Energy Distribution on the source linear size.…”

Section: Evolution Of Gps Sourcesmentioning

confidence: 99%

The X-ray view of giga-hertz peaked spectrum radio galaxies

Tengstrand

Guainazzi

Siemiginowska

et al. 2009

A&A

100

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Context. This paper presents the X-ray properties of a flux-and volume-limited complete sample of 16 giga-hertz peaked spectrum (GPS) galaxies. Aims. This study addresses three basic questions in our understanding of the nature and evolution of GPS sources: a) What is the physical origin of the X-ray emission in GPS galaxies? b) Which physical system is associated with the X-ray obscuration? c) What is the "endpoint" of the evolution of compact radio sources? Methods. We discuss in this paper the results of the X-ray spectral analysis, and compare the X-ray properties of the sample sources with radio observables. Results. We obtain a 100% (94%) detection fraction in the 0.5-2 keV (0.5-10 keV) energy band. GPS galaxy X-ray spectra are typically highly obscured ( N GPS H = 3 × 10 22 cm −2 ; σ N H 0.5 dex). The X-ray column density is larger than the HI column density measured in the radio by a factor 10 to 100. GPS galaxies lie well on the extrapolation to high radio powers of the correlation between radio and X-ray luminosity known in low-luminosity FR I radio galaxies. On the other hand, GPS galaxies exhibit a comparable X-ray luminosity to FR II radio galaxies, notwithstanding their much larger radio luminosity. Conclusions. The X-ray to radio luminosity ratio distribution in our sample is consistent with the bulk of the high-energy emission being produced by the accretion disk, as well as with dynamical models of GPS evolution where X-rays are produced by Compton upscattering of ambient photons. Further support to the former scenario comes from the location of GPS galaxies in the X-ray to O[iii] luminosity ratio versus N H plane. We propose that GPS galaxies are young radio sources, which would reach their full maturity as classical FR II radio galaxies. However, column densities ∼ > 10 22 cm −2 could lead to a significant underestimate of dynamical age determinations based on the hotspot recession velocity measurements.

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Compact Symmetric Objects and the Evolution of Powerful Extragalactic Radio Sources

Cited by 248 publications

References 0 publications

Soon After the Birth of Radio Sources

Soon After the Birth of Radio Sources

The Dynamic Evolution of Young Extragalactic Radio Sources

The X-ray view of giga-hertz peaked spectrum radio galaxies

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