Collection: Hourglass SMBs
A radio source with two oppositely directed symmetric lobes. Sometimes these will be joined together by the outer contours, other times they will appear separate. Often there will be an infrared galaxy somewhere near half way between the lobes. These are the most powerful black hole eruptions in the Universe, technically known to astronomers as Fanaroff-Riley Type II radio sources, defined as those objects for which the distance between the places of brightest radio emission is more than half the size of the entire radio source. They are sometimes called “edge-brightened” sources.