A team led by Indian radio astronomers has discovered 34 new giant radio sources (GRSs), some of which are among the most distant ever identified. The discovery, announced by the National Centre for Radio Astrophysics, Tata Institute of Fundamental Research (NCRS-TIFR), highlights these colossal cosmic phenomena as some of the largest objects in the universe.
The GRSs were identified using the Giant Metrewave Radio Telescope (GMRT), located near Khodad village in Pune. This telescope, built and operated by NCRS-TIFR, played a crucial role in the discovery. The research team, including PhD students Netai Bhukta and Souvik Manik, along with astronomers Sabyasachi Pal and Sushanta K. Mondal, utilized data from the TIFR GMRT Sky Survey, which is particularly effective at low frequencies.
“GRSs represent the final stage of radio galaxy evolution due to their vast sizes,” said Pal. “The enormous projected lengths of these sources make them key candidates for understanding the evolution of radio galaxies and the intergalactic medium that confines their lobes far from their parent galaxies.”
Pal explained that these GRSs stretch across millions of light-years, equivalent to lining up tens of thousands of Milky Ways in a row. At the core of these radio sources lies a supermassive black hole, with a mass ranging from ten million to one billion times that of the Sun. This black hole acts as the central engine, pulling in surrounding matter, which becomes ionized and creates powerful electromagnetic forces. These forces propel material outward, producing vast jets of hot plasma and massive lobes of radio emissions that extend far beyond the visible size of the galaxy.
Interestingly, two of the newly discovered GRSs challenge existing theories by growing in environments that were previously thought to be low-density, suggesting that factors other than environmental conditions may influence their size.
This groundbreaking discovery not only emphasizes India’s growing capabilities in space research but also promises to deepen our understanding of the universe. The researchers plan to present new samples with detailed physical properties based on multi-wavelength observations, further illuminating these cosmic giants.