Durham University, UK | 2019 Aug 06
Astronomers have identified a rare moment in the life of some of the universe’s most energetic objects.
Quasars were first observed 60 years ago, but their origins still remain a mystery. Now researchers at Durham University, UK, have spotted what they suggest is a “brief transition phase” in the development of these galactic giants that could shed light on how quasars and their host galaxies evolve.
Quasars are powered by the energy from supermassive black holes at their centres as they feed on surrounding gases. They are thousands of times brighter than galaxies like our Milky Way, and the majority are blue in colour. However, a significant number are red as they are viewed through huge clouds of dust and gas that obscure them from view.
The conventional view of red quasars is that they are actually blue quasars that are angled away from our line-of-sight. Instead, the Durham team has ruled this model out and have shown that red quasars are likely to be the result of a brief, but violent, phase in the evolution of galaxies when the black hole ejects a large amount of energy into the surrounding clouds of dust and gas. This injection of energy blows away the dust and gas to reveal a blue quasar. ...
Fundamental Differences in the Radio Properties of Red and Blue Quasars:
Evolution Strongly Favoured over Orientation ~ Lizelke Klindt et al