Radio Galaxies : Discovery

Radio Galaxies : Discovery

A team of astronomers from the National Centre of Radio Astrophysics (NCRA) Tata Institute of Fundamental Research (TIFR) Pune; Physical Research Laboratory (PRL) Ahmedabad; and the University of Oxford recently discovered several ‘elusive dying radio galaxies’.

• Radio Galaxies, also known as radio-luminous galaxies or radio-loud galaxies, are a particular type of active galaxy that emits more light at radio wavelengths than at visible wavelengths.
• These happen through the interaction between charged particles and strong magnetic fields related to supermassive black holes at the galaxies’ center.
• Radio galaxies are driven by non-thermal emissions.
• They are much bigger than most of the other galaxies in the universe.
• There are two broad classes of radio galaxies:
  • Core-halo radio galaxies:
    • They exhibit radio emission from a region concentrated around the nucleus of the galaxy.
    • The region of radio emission is comparable in size to the optically visible galaxy.
  • Lobed radio galaxies:
    • They display great lobes of radio emission extending, in some cases, for millions of light years beyond the optical part of the galaxy.