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arXiv · 1008.2706

Double-double radio galaxies: further insights into the formation of the radio structures

Catherine Brocksopp·Christian Kaiser·Arno Schoenmakers·Ger de Bruyn
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Abstract

Double-double radio galaxies (DDRGs) offer a unique opportunity for us to study multiple episodes of jet activity in large-scale radio sources. We use radio data from the Very Large Array and the literature to model two DDRGs, B1450+333 and B1834+620, in terms of their dynamical evolution. We find that the standard Fanaroff-Riley II model is able to explain the properties of the two outer lobes of each source, whereby the lobes are formed by ram-pressure balance of a shock at the end of the jet with the surrounding medium. The inner pairs of lobes, however, are not well-described by the standard model. Instead we interpret the inner lobes as arising from the emission of relativistic electrons within the outer lobes, which are compressed and re-accelerated by the bow-shock in front of the restarted jets and within the outer lobes. The predicted rapid progression of the inner lobes through the outer lobes requires the eventual development of a hotspot at the edge of the outer lobe, causing the DDRG ultimately to resemble a standard Fanaroff-Riley II radio galaxy. This may suggest that DDRGs are a brief, yet normal, phase of the evolution of large-scale radio galaxies.

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Catherine Brocksopp, Christian Kaiser, Arno Schoenmakers, Ger de Bruyn. 2010-08-16. Double-double radio galaxies: further insights into the formation of the radio structures. https://doi.org/10.1111/j.1365-2966.2010.17456.x

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