Strange glowing 'bow-and-arrow' structure may be a giant cosmic shock wave created by a supersonic galaxy collision

A bizarre radio galaxy discovered by a citizen scientist has left astronomers puzzled, revealing a never-before-seen "bow-and-arrow" structure that could offer rare insight into how galaxies are reshaped by colossal shock waves as they plunge through galaxy clusters. Named RAD-BAARG (short for Radio Bow-And-Arrow Radio Galaxy), the object spans nearly 1.8 million light-years across, making it almost 18 times wider than the Milky Way . Its unusual structure was first identified by a citizen scientist participating in the RAD@home Astronomy Collaboratory, which allows volunteers to review telescope data and flag unusual features that might otherwise be missed. Astronomers say they haven't seen anything like it. "The structure of this source is unlike that of any radio galaxy I have seen in the last 25 years," the University of Mumbai's Ananda Hota said in a statement published by the Royal Astronomical Society. The statement adds that astronomers believe the structure may be "one of the clearest known radio signatures of a giant bow shock generated by a galaxy falling supersonically into a cluster environment." Following its discovery, researchers studied the object using observations from the LOFAR (Low Frequency Array) Two-meter Sky Survey (LoTSS), one of the deepest low-frequency radio surveys ever conducted and particularly well suited to detecting faint, diffuse radio emissions. …