Origin of the ring structures in Hercules A

The prominent radio source Hercules A features complex structures in its lobes. Although it is one of the most comprehensively studied sources sky, origin ring lobes remains an open question. We present first sub-arcsecond angular resolution images at low frequencies (<300 MHz) A, made with International LOFAR Telescope. With addition data from Karl G. Jansky Very Large Array, we mapped structure 144 MHz to 7 GHz. explore rings within and test whether their properties are best described by a shock model, where waves produced jet propagating lobe, or inner-lobe formed decelerated jetted plasma. From spectral index mapping our large frequency coverage reveals that curvature different spectra increases distance away central active galactic nucleus. demonstrate shape consistent synchrotron aging, which speaks favor model deposition material past periods intermittent core activity.