Leiden astronomers have discovered the largest radio galaxy ever

The discovery casts doubt on popular ideas about the growth of radio galaxies. The researchers will soon publish their findings in the journal Astronomy and astrophysics.

There is a supermassive black hole in the center of many galaxies, which prevents the formation of new stars and therefore has a significant impact on the life course of the entire galaxy. Sometimes things get turbulent: the black hole then creates two jet streams, spewing building material for young stars out of the galaxy at nearly the speed of light. Stellar dust gets so hot that it breaks down into plasma and emits ‘radio light’. The team of researchers from Leiden, Hertfordshire, Oxford and Paris has now captured this light using the European Lofer Telescope, whose core is located in the Netherlands.

The picture of Rishi’s plasma is special, because such a large structure has never before been seen by a single galaxy. The discovery shows that the fields of influence of some galaxies extend far beyond their immediate surroundings. To what extent exactly? It’s hard to determine. Astronomical images do not contain depth. Therefore, only a minimum length of the radio array can be given. But even this lower bound, which is over 16 million light-years away, is huge.

Primordial Heaven Deity

The “radio giant” is three billion light-years away. Despite this amazing distance, it looks as large as the moon in the sky. This in itself was an indication that the structure should have a standard length. The fact that the LOFAR telescope’s radio eyes only now observed the giant has something to do with the fact that the plasma plumes are relatively faint.

Researchers have named the giant structure Alcyoneus after the son of Ouranos, the ancient Greek god of heaven. This legendary Alcyoneus was a giant who fought against Heracles and other Olympians for supremacy over the universe. What Alcyoneus owes its record size, remains a mystery at present.

Photo: Martijn Oei et al.