Discovery of a spiral-host episodic radio-galaxy
  We report the discovery of a unique radio galaxy at z=0.137, which could
possibly be the second spiral-host large radio galaxy and also the second
triple-double episodic radio galaxy. The host galaxy shows signs of recent star
formation in the UV but is optically red and is the brightest galaxy of a
possible cluster. The outer relic radio lobes of this galaxy, separated by ~1
Mpc, show evidence of spectral flattening and a high fraction of linear
polarisation. We interpret that these relic lobes have experienced
re-acceleration of particles and compression of the magnetic field due to
shocks in the cluster outskirts. From the morphology of the relics and galaxy
distribution, we argue that re-acceleration is unlikely to be due to a
cluster-cluster merger and suggest the possibility of accretion shocks. The
source was identified from SDSS, GALEX, NVSS and FIRST survey data but we also
present follow up optical observations with the Lulin telescope and 325 MHz low
frequency radio observations with the GMRT. We briefly discuss the scientific
potential of this example in understanding the evolution of galaxies and
clusters by accretion, mergers, star formation, and AGN feedback.
