Radio Galaxy Zoo: discovery of a poor cluster through a giant wide-angle tail radio galaxy

We have discovered a previously unreported poor cluster of galaxies (RGZ-CL J0823.2+0333) through an unusual giant wide-angle tail radio galaxy found in the Radio Galaxy Zoo project. We obtained a spectroscopic redshift of \(z=0.0897\) for the E0-type host galaxy, 2MASX J08231289+0333016, leading to M\(_r = -22.6\) and a \(1.4\,\)GHz radio luminosity density of \(L_{\rm 1.4} = 5.5\times10^{24}\) W Hz\(^{-1}\). These radio and optical luminosities are typical for wide-angle tailed radio galaxies near the borderline between Fanaroff-Riley (FR) classes I and II. The projected largest angular size of \(\approx8\,\)arcmin corresponds to \(800\,\)kpc and the full length of the source along the curved jets/trails is \(1.1\,\)Mpc in projection. X-ray data from the XMM-Newton archive yield an upper limit on the X-ray luminosity of the thermal emission surrounding RGZ J082312.9+033301,at \(1.2-2.6\times10^{43}\) erg s\(^{-1}\) for assumed intra-cluster medium temperatures of \(1.0-5.0\,\)keV. Our analysis of the environment surrounding RGZ J082312.9+033301 indicates that RGZ J082312.9+033301 lies within a poor cluster. The observed radio morphology suggests that (a) the host galaxy is moving at a significant velocity with respect to an ambient medium like that of at least a poor cluster, and that (b) the source may have had two ignition events of the active galactic nucleus with \(10^7\,\)yrs in between. This reinforces the idea that an association between RGZ J082312.9+033301, and the newly discovered poor cluster exists.