FIRST winged radio galaxies with X and Z symmetry
  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.
