Hubble Space Telescope observations of obscuration rings in Hercules A: Implications for energy transport in powerful radio galaxies

We have used the Hubble Space Telescope to obtain snapshot images of Hercules A, the host galaxy to the powerful radio source 3C 348, through a broadband red filter. We report the discovery of interlocking, kiloparsec-scale rings of obscuration aligned near the radio axis and slightly offset from the galaxy's nucleus. We discuss possible models for these rings and their implications for models of energy transport in extragalactic radio jets.