Indian team discovers rare ‘bow and arrow’ radio galaxy two billion light years from Earth
Twelve Indian researchers across three countries have discovered a rare, nonconformist radio galaxy, shaped like a bow and arrow and 1.8 million light years wide
Twelve Indian researchers across three countries have discovered a rare, nonconformist radio galaxy, shaped like a bow and arrow and 1.8 million light years wide, located approximately 2 billion light years from Earth. A light year is about 5.88 trillion miles. A radio galaxy, powered by supermassive black holes at its core, is a type of active galaxy that emits very high amounts of energy in the form of radio waves. The newly discovered arc-like system has been named RAD-BAARG, where RAD stands for RAD@home Astronomy Collaboratory, India’s first citizen science research platform in astronomy based at Kharghar in Navi Mumbai. BAARG expands to Bow And Arrow Radio Galaxy. The research team’s paper, titled “RAD@home discovery of a bow-and-arrow radio galaxy tracing a ∼560 kpc bow-shock structure in a multi-halo environment”, was published in the journal Monthly Notices of the Royal Astronomical Society on June 22. According to the paper, the “highly unusual” and asymmetric structure is unlike those seen in standard radio galaxies. Kpc is short for kiloparsec, a unit of astronomical distance equal to 1,000 parsecs, or about 3,260 light-years. The lead author of the study is Ananda Hota of the University of Mumbai and the founder-director of the 13-year-old RAD@home, which enables university students and others to conduct extragalactic research and make astronomical discoveries from the comfort of their homes.
The other authors — all associated with RAD@home — are Pratik Dabhade of the Poland-based Centre for Nuclear Research; Shubhrangshu Ghosh of Sikkim’s Shri Ramasamy Memorial (SRM) University; Mitali Damle of New York University Abu Dhabi; Souvik Manik and Sabyasachi Pal of West Bengal’s Midnapore City College; C. Konar of Noida-based Amity University; Sagar Sethi of Poland’s University of Warmia and Mazury; and Pranim Limbo, Aditya Sahasranshu, Sravani Vaddi, and Arundhati Purohit. Supersonic fall The RAD-BAARG was found using ultra-sensitive images from the LOFAR (Low Frequency Array) Two-metre Sky Survey, one of the deepest radio surveys ever conducted at low frequencies. Its discovery follows the team’s 2025 identification of the farthest and most powerful Odd Radio Circle known at that time. According to Mr. Ghosh, the huge black holes in radio galaxies launch enormous jets of relativistic magnetised plasma into intergalactic space. In the RAD-BAARG, one of the jets appears to interact with a large bow-shock-like structure formed as the host galaxy falls through the surrounding hot gas toward a nearby cluster of galaxies. “Similar to the shock wave formed ahead of a supersonic aircraft, a galaxy moving faster than the speed of sound in the surrounding intra-cluster medium can compress the ambient gas and generate a large-scale shock front.
The BriefWire