相关论文: Two Types of Radio Galaxies: A New Approach

The tailed radio galaxies that have been called ``Type I'' are not a uniform set. To study their dynamics, we have used the Ledlow-Owen data set, which provides a new sample of 250 radio galaxies in nearby Abell clusters. These sources…

We describe the inter-dependence of four properties of classical double radio sources - spectral index, linear size, luminosity and redshift - from an extensive study based on spectroscopically-identified complete samples. We use these…

A small number of double-lobed radio galaxies (17 from our own census of the literature) show an additional pair of low surface brightness `wings', thus forming an overall `X'-shaped appearance. The origin of the wings in these radio…

We present a systematic search for two types of very unusual astronomical objects: Galactic stars and spiral galaxies with double radio lobes, i.e. radio emission on opposite sides of the optical object, suggesting the ejection of jets from…

This review discusses three ways in which radio galaxies and other high-redshift objects can give us information on the nature and statistics of cosmological inhomogeneities, and how they have evolved between high redshift and the present:…

The radio structures and optical identifications of a sample of 242 sources classified as double-double radio sources by Proctor (2011) from a morphological study of sources in the FIRST (Faint Images of the Radio Sky at Twenty centimeters)…

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)…

X-shaped radio galaxies are defined by their peculiar large-scale radio morphology. In addition to the classical double-lobed structure they have a pair of low-luminosity wings that straddles the nucleus at almost right angles to the active…

The simple, yet profoundly far-reaching classification scheme based on extended radio morphologies of radio galaxies, the Fanaroff-Riley classification has been a cornerstone in our understanding of radio galaxies. Over the decades since…

The majority of this paper is devoted to discrete radio sources, and their consequences for cosmology. Three main issues are considered: (i) what makes a galaxy radio loud?; (ii) what do we know about how the population of radio-loud…

Analytical models describing the dynamics of lobed radio sources are essential for interpretation of the tens of millions of radio sources that will be observed by the Square Kilometre Array and pathfinder instruments. We propose that…

Many of the powerful radio galaxies observed at high redshift are very small, presumably because they are very young. A simple model, which treats the radio source as a bubble expanding into a radially stratified medium, is capable of…

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…

We show that a dual-population unification scheme provides a successful paradigm with which to describe the evolution and beaming of all bright extragalactic radio sources. The paradigm consists of two intrinsic radio-source populations,…

The change in the slope of the radio source counts suggests the emergence of a new population of radio galaxies at mJy and sub-mJy levels. Our understanding of such faint radio sources has advanced over the last decade through increasingly…

Hybrid sources that present FR I - like jet on the one side of the radio core and FR II - like on the other are rare class of objects that may posses key to understanding the origin of FR division. We presents information connected with the…

We present in this paper a detailed study of a new sample of large angular size FR I and FR II radio galaxies and compare the properties of the two classes. As expected, a pure morphology based distinction of FR Is and FR IIs corresponds to…

Giant radio sources form the linear size extreme of the extra-galactic radio source population. Using the WENSS survey, we have selected a complete sample of these sources. We have investigated the properties of their radio structures. We…

In this paper we discuss the demographics of the radio blazar population: (i) what are their parent (`unbeamed') sources and (ii) what magnitude and/or type of evolution have they undergone ? The discussion is based on models of radio…

Determining the energy spectrum of an electron population can give key insights into the underlying physics of a radio source; however, the lack of high resolution, broad-bandwidth observations has left many ambiguities in our understanding…