Radio Galaxy : Discovery
Astronomers recently reported the discovery of 63 new giant 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’ centre.
- Radio galaxies are driven by non-thermal emissions.
- They are much bigger than most of the other galaxies in the universe.
- The first radio galaxy to be discovered, and still the brightest, is called Cygnus A.
- 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.
- Some radio galaxies have a single lobe, but more often, the lobes are double, arrayed on both sides of the optical galaxy.
- Core-halo radio galaxies: