Hydra A at Low Radio Frequencies

Abstract

We present new, low-frequency images of the powerful FR I radio galaxy Hydra A (3C 218). Images were made with the Very Large Array (VLA) at frequencies of 1415, 330, and 74 MHz, with resolutions on the order of 20". The morphology of the source is seen to be more complex and even larger than previously known, and extends nearly 8' (530 kpc) in a North-South direction. The southern lobe is bent to the east and extends in that direction for nearly 3' (200 kpc). In addition, we find that the northern lobe has a flatter spectral slope than the southern lobe, consistent with the appearance of greater confinement to the south. We measure overall spectral indices α^{330}_{74} = -0.83 and α^{1415}_{330} = -0.89.