Related papers: FIRST `Winged' and `X'-shaped Radio Source Candida…

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 do not fully understand the dynamics and evolution of a radio galaxy. Models of classical double (Type II) sources are in a reasonable state, but these objects are rare. Non-type II sources (generically called Type I) are far more…

Signatures of the re-occurrence of activity in radio-loud AGNs, indicated either by the so-called double-double or X-shaped structures, have been observed in a number of radio sources. All such objects known to date have linear sizes of the…

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)…

Context. X-shaped radio galaxies (XRGs) exhibit a pair of bright primary lobes and a pair of weak secondary lobes (wings), which are oriented with an angle that gives the structure a cross-like shape. Though several theoretical models have…

We present a low-frequency imaging study of an extended sample of X-shaped radio sources using the Giant Metrewave radio telescope (GMRT) at two frequencies (610 and 240 MHz). The sources were drawn from a Very Large Array FIRST-selected…

Jet precession is sometimes invoked to explain asymmetries in radio galaxy (RG) jets and "X/S/Z-shape" radio galaxies, caused by the presence of a binary black hole companion to the source active galactic nucleus (AGN) or by accretion…

X-shaped Radio Galaxies (XRGs) develop when certain extra-galactic jets deviate from their propagation path. An asymmetric ambient medium (Back-flow model) or complex Active Galactic Nuclei activity (Jet-reorientation model) enforcing the…

We present new 144-MHz LOFAR observations of the prototypical `X-shaped' radio galaxy NGC 326, which show that the formerly known wings of the radio lobes extend smoothly into a large-scale, complex radio structure. We argue that this…

We present results from a survey for gravitationally lensed radio lobes. Lensed lobes are a potentially richer source of information about galaxy mass distributions than lensed point sources, which have been the exclusive focus of other…

We present some results from an archival VLA study of ultraluminous X-ray source s (ULXs). These unresolved non-nuclear X-ray sources have luminosities (L_X >= 1 0^39 ergs/sec) which may require somewhat exotic explanations, such as…

A comparison of the recent LOFAR 144 MHz map of the radio source 3C 223.1 (J094124.028+394441.95) with the VLA maps at 4.9 GHz and 8.3 GHz that we built based on archival data, establishes this X-shaped radio galaxy (XRG) as a singularly…

Coalescence of super massive black holes (SMBH's) in galaxy mergers is potentially the dominant contributor to the low frequency gravitational wave background (GWB). IIt was proposed by Merritt and Ekers (2002) that X-shaped radio galaxies…

This review provides the background and current perspective of some of the striking asymmetries exhibited by extragalactic double-lobed radio sources, paying special attention to the reported interrelationships among some of them. We…

To investigate the origins of wide-angle tailed radio sources (WATs), we have compiled a sample of these systems in Abell clusters for which X-ray data exist. Contrary to conventional wisdom, the WATs are found to be significantly displaced…

Taking a clue from their sharp-edged (strip-like) morphology observed in several cases, a new mechanism is proposed for the formation of the emission gaps seen between the radio lobes of many powerful extragalactic double radio sources.…

The origin and evolution of supernova remnants of the mixed-morphology class is not well understood. Several remnants present distorted radio or X-ray shells with jet-like structures. G290.1-0.8 (MSH 11-61A) belongs to this class. We aim to…

We have made a deep search for radio emission from all the northern hemisphere supersoft X-ray sources using the VLA and MERLIN telescopes, at 5 and 8.4 GHz. Three previously undetected sources: T Pyx, V1974 Cygni and RX J0019.8+2156 were…

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 have formed a new sample which consists of extended extragalactic radio sources without obvious active galactic nuclei (AGN) in them. Most of these sources appear to be dead double radio sources. These sources with steep spectra ($\alpha…