A team of astrophysicists led by Indian-born Aayush Saxena at the Leiden Observatory in the Netherlands has discovered the farthest known radio galaxy at a distance of 12 billion light years. The discovery sets a new record for the farthest known radio galaxy, a record that has remained untouched for nearly 20 years. The radio galaxy was apparently created within the first 7 percent of the universe’s current known lifespan.
For the discovery, the team used three telescopes. The first was the Giant Meterwave Radio Telescope located near Pune which was used to initially identify the galaxy. The distance to the galaxy was measured using the Gemini telescope in Hawaii. However, the age of the galaxy was measured using the Large Binocular Telescope in Arizona. The distance of radio galaxies is measured in redshift, which is the frequency of light becoming longer in wavelength, that is, towards the red end of the visible light spectrum. Redshifts are denoted by the letter z, followed by a number. If the number is positive, then it means the observed object is moving away from the point of observation (redshift) and if the number has a negative value (blueshift) then it means its moving closer.
In the case of this newest discovery, the redshift value is z=5.72, meaning that the galaxy is perceived as it was when the universe was only a billion years old. The previous record for the farthest object was held by a radio galaxy with a redshift of z=5.19 discovered in 1999. This also means that the light is perceived on Earth by the team is roughly 12 billion years old.
The existence of such galaxies so far away in the distant Universe has surprised astronomers. The discovery of such galaxies at such large distances is important for the understanding of the formation and evolution of galaxies. Studying these radio galaxies in detail also sheds light on the formation of primordial black holes, which have driven and regulated the growth of galaxies. Radio galaxies are rare celestial objects as they are colossal galaxies with a supermassive black hole at their core. The supermassive black hole violently pulls gas and dust from its surroundings, causing the creation of high energy jetstreams which can accelerate charged particles in the vicinity to the speed of light