Pune radio telescope helps discover farthest galaxy




Aayush Saxena, a researcher at a Dutch observatory, and his colleagues from various countries have found the most distant radio galaxy yet discovered — 12 billion lightyears from Earth — with initial data derived from a sky survey done at India’s Giant Metrewave Radio Telescope (GMRT) seven years ago.


GMRT is an array of 30 fully steerable parabolic radio telescopes of 45m diametre located in Khodad, about 60km from here, and operated by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research.

Saxena and his colleagues from institutes in Leiden (the Netherlands), Brazil, Italy and the UK discovered the radio galaxy in June, and named it TGSS1530. The galaxy was perceived as it appeared when the universe was only 800 million years old, just 7% of its current age, stated a study accepted by the journal, Monthly Notices, of the Royal Astronomical Society.

“GMRT had done an allsky survey at 150mghz around seven years ago. This was the lowest frequency at which a survey has been done. The survey is like a gold mine and people are discovering new things from it,” GMRT observatory dean Yashwant Gupta told TOI on Thursday.

The observation by researchers in the Netherlands was a chain of inferences that started from identifying likely objects from a 150mghz survey. “This discovery is the first signature of the GMRT data and researchers have made different follow-up observations to confirm it,” he said. “This activity initiates launch of high-energy jet streams that are capable of accelerating charged particles around the super-massive black hole to almost the speed of light. These jets are observed at radio wavelengths. The fact that such galaxies exist in the distant universe has surprised astronomers,” he said.

Radio galaxies are galaxies that contain a super-massive black hole of millions of solar mass and emit copious amount of radio waves.

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