A team at the National Center for Radio Astrophysics in the western state of Maharashtra’s city of Pune found the galaxy – J021659-044920 – towards constellation Cetus, local media reported on Tuesday.
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Ghost of a rare giant radio galaxy was discovered by Indian astronomers from the National Centre for Radio Astrophysics (NCRA, TIFR) in Pune have discovered, using the Giant Metrewave Radio Telescope (GMRT).
Such galaxies with extraordinarily giant “radio measurement” are appropriately referred to as giant radio galaxies.
Under a few particular circumstances, the central black gap might cease producing the radio jet, after which the brilliant radio lobes fade away, inside a number of million years, resulting from lack of replenishment.
While discovering a galaxy that spans 100,000 light years is certainly an accomplishment in itself, it didn’t take the astronomers long to realize there was something even more extraordinary about their finding. That means it’s really old in cosmic terms (but not quite as old as the oldest object astronomers have ever found, a galaxy 13 billion light years away called UDFy-38135539). “So, the galaxy is seen by us today, as it was, when the universe was about one-third of its present age”. These galaxies release powerful radio waves and have a tendency of being roughly 4 million light years from end-to-end.
Image: J021659-044920. The red and yellow lobes are the galaxy’s radio lobes. These black holes produce twin jets, emitting lobes of radio waves out into interstellar space. This latter sequence leads to faint X-ray emission, which is seen to originate from the radio lobes of this galaxy.
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“The galaxy is a phase when radio emission are dying away, which makes it quite unique”, said Dr Yogesh Wadadekar, scientist at NCRA. This dying phase is where the radio jet appears to have switched off and the radio lobes have started fading. Tamhane and his colleagues published their discovery in the journal Monthly Notices of the Royal Astronomical Society. For their analysis, the team combined their GMRT observations with previous observations made with a slew of worldwide ground and space based telescope facilities – XMM-Newton Space Telescope in X-ray, the Japanese Subaru telescope in optical, UK’s Infrared Telescope in near-infrared, Nasa’s Spitzer Space Telescope in mid-infrared and the Jansky Very Large Array (USA) in high frequency radio bands.
