An international team of astronomers has discovered the most distant ‘Radio-Loud’ Quasar with the help of the European Southern Observatory’s Very Large Telescope (ESO’s VLT).
- Quasars are very luminous objects in faraway galaxies that emit jets at radio frequencies.
- The word quasar is short for “quasi-stellar radio source”.
- The name, which means star-like emitters of radio waves, was given in the 1960s when quasars were first detected.
- The name is retained today, even though astronomers now know most quasars are faint radio emitters. In addition to radio waves and visible light, quasars also emit ultraviolet rays, infrared waves, X-rays, and gamma-rays.
- Most quasars are larger than our solar system. A quasar is approximately 1 kiloparsec in width.
- They are only found in galaxies that have supermassive blackholes which power these bright discs.
- Black hole refers to a point in space where matter is so compressed as to create a gravity field from which even light cannot escape.
- Most active galaxies have a supermassive black hole at the centre which sucks in surrounding objects.
- Quasars are formed by the energy emitted by materials swirling around a blackhole right before being sucked into it.
- They are further categorised into the “radio-loud” and the “radio-quiet” classes.
- They are with powerful jets that are strong sources of radio-wavelength emission.
- These make up about 10% of the overall quasar population.
- They are those quasars lacking powerful jets, with relatively weaker radio emission than the radio-loud population.
- The majority of quasars (about 90%) are radio-quiet.