X-shaped radio galaxies are a subclass of radio sources that exhibit a pair of secondary low surface brightness radio lobes oriented at an angle to the primary high surface brightness lobes. Sometimes, the secondary low brightened lobes emerge from the edges of the primary high brightened lobes and form a Z-symmetric morphology. We present a systematical search result for X-shaped radio galaxies (XRGs) and Z-shaped radio galaxies (ZRGs) from the VLA Faint Images of the Radio Sky at Twenty-Centimeters (VLA FIRST) Survey at 1.4 GHz. Our search yields a total of 296 number of radio sources, out of which 161 are XRGs and 135 are ZRGs. We have also made optical identification of these sources from the different available literature. J1124+4325 and J1319+0502 are the farthest known XRG and ZRG, respectively. We have estimated spectral index and radio luminosity of these radio sources and made a comparative study with previously detected XRGs and ZRGs. The average value of luminosities for XRGs is higher than that of ZRGs. With the help of a large sample size of the newly discovered XRGs and ZRGs, various statistical properties of these sources are studied. Out of 161 XRGs presented in the current paper, 70% (113) are FR II radio galaxies and 13% (20) are FR I radio galaxies. For 28 XRGs, the morphology is complex and could not be classified. For XRGs, the statistical studies are done on the angle between the major axis and minor axis and the relative size of the major and minor axes. For the ZRGs a statistical study is done on the angular size.
The head–tail (HT) morphology of radio galaxies is seen for a class of radio sources where the primary lobes are being bent in the intercluster weather due to strong interactions between the radio jets and their respective intracluster medium. A systematic search has been carried out for new HT radio galaxies from the Very Large Array Faint Images of the Radio Sky at Twenty-Centimeters survey database at 1400 MHz. Here, we present a catalog of 717 new HT sources, among which 287 are narrow-angle tail (NAT) sources whose opening angle between the two lobes is less than 90°, and 430 are wide-angle tail (WAT) whose the opening angle between the two lobes is greater than 90°. NAT radio sources are characterized by tails bent in a narrow “V”-like shape; the jet bending in the case of WAT radio galaxies are such that the WATs exhibit wide “C”-like morphologies. Optical counterparts are found for 359 HT sources. We report HT sources with luminosity ranges 1038 ≤ L 1.4 GHz ≤ 1045 erg s−1 and redshifts up to 2.01. The various physical properties of these HT sources are mentioned here. Some statistical studies have been done for this large number of newly discovered HT sources.
Miscellaneous Radio Galaxies (MRGs) are very rare kind of radio galaxies that exhibit unusual and different jet alignment and orientation from a typical radio galaxy. The peculiar and unique morphology of this type of radio source makes them a special case of study. In this paper, we report the identification of fifteen MRGs from VLA Faint Images of the Radio Sky at Twenty-Centimeters (VLA FIRST) Survey. The MRGs are identified manually by visual inspection of the FIRST database (December, 2017). The individual radio morphology of each sources are cross-checked at different frequencies from other surveys like TIFR GMRT Sky Survey at 150 MHz and Westerbork Northern Sky Survey at 325 MHz. We also identify the associated optical counterparts from the Sloan Digital Sky Survey (SDSS), where available. The different physical parameters like spectral index and radio luminosity of these MRGs are also estimated. An overview on the origin of these unique sources are also drawn.
A small number of extragalactic radio sources disclose a pair of low-surface-brightness radio lobes, known as “wings,” aligned at a certain angle to the primary jets. Such exotic sources are known as “winged” radio sources. Here we report the new identification of a total of 26 “winged” radio sources from the LOFAR Two-meter Sky Survey First Data Release (LoTSS DR1). Out of the 26 “winged” sources, 14 are identified as X-shaped radio galaxies and the remaining 12 as Z-shaped radio galaxies. The available optical counterpart of each radio galaxy is cataloged along with its estimated redshift. Among the 26 sources, 15 candidates are classified as FR-II radio galaxies, and two are classified as FR-I type. For nine candidates, no conclusions are drawn due to their complex morphology. We also calculate the physical parameters such as spectral index, radio luminosity, and power of the sources. We have made a statistical study of the spectral index by combining our estimated value with the spectral index collected from previous works. A mean value of spectral index of 0.71 is obtained.
Using the 144 MHz Low-Frequency Array (LOFAR) telescope, We undelook a search for Miscellaneous Radio Galaxies (MRGs) whose morphological structures are different from known structures. Reseaons of study of these type sources due to their unique and peculiar morphology. Here, we report four MRGs from LOFAR Two Metre Sky Survey first data release (LoTSS DR1) at 144 MHz frequency. The MRS is identified manual visual search (MVS) from LoTSS DR1 data catalogue. We also check their radio morphology from other surveys like The NRAO VLA Sky Survey (NVSS) at 1400 MHz. The corresponding optical counterparts are also identified from Sloan Digital Sky Survey (SDSS), where available. We have estimated different physical parameters like spectral index, radio luminosity, radio power of these MRGs.
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