August 17, 2022
A galaxy measuring 16.3 light miles across may be the largest galaxy ever discovered

A galaxy measuring 16.3 light miles across may be the largest galaxy ever discovered

Astronomers led by Martin Uwe of the Leiden Observatory in the Netherlands have discovered a giant radioactive galaxy located 3 billion light-years from Earth. Called Alcyoneus, it reaches 5 megaparsecs in length, 16.3 million light-years in length, making it the largest known structure of galactic origin.

For astronomers, the discovery could help to better understand radio galaxies, a type of giant galaxy much brighter than “normal” galaxies.

Radio galaxies are another mystery in a being Still full of unanswered questions. It is very luminous and consists of a host galaxy – a group of stars orbiting around one of them Black hole Extremely massive, like our Milky Way galaxy – as well as huge jets and lobes looming in its center.

According to astronomers, these jets and lobes come from the supermassive black hole at the center of the galaxy and can travel long distances before splitting into lobes that emit radio waves.

This process is completely natural, not least because the Milky Way galaxy where we live also has radio lobes. What caught the attention of scientists in this case was the fact that it was not yet known why some galaxies have gigantic lobes the size of a megaparsec. In these cases, they are called “radio giant galaxies,” and the most extreme of them may help explain this growth.

“If there are features of the host galaxies that are an important reason for the growth of radio-giant galaxies, the hosts of the largest are likely to have them. Likewise, if there are special, large-scale environments that are very conducive to the growth of radio-giant galaxies, the largest of them are likely to be present in them,” The astronomers wrote in the study.

Details of the radio galaxy Alcyoneus

Data from the radio galaxy Alcyoneus was processed to remove radio emissions that could interfere with the radio lobe detections. The images of this process represent the search for radioactive lobes of a galaxy with high sensitivity and through the analysis of the material the researchers discovered the largest structure formed by a single galaxy, Alcyoneus.

After taking the lobe measurements, the team of astronomers used the Digital Sky Survey to try to understand the properties of the host galaxy. They found that it is an ordinary elliptical galaxy, with a mass about 240 billion times the mass of our Sun, and that it contains a supermassive black hole with a mass of 400 million times the mass of the Sun. Alcyoneus and its host have both a stellar mass and a wormhole. Stars smaller than those in intermediate radio giant galaxies.

“In addition to geometry, Alcyoneus and its host are strangely common: the total low-frequency luminosity density, stellar mass, and black hole supermass are all inferior to giant radio galaxies, albeit similar,” the astronomers wrote.

They further explained that very massive galaxies or supermassive black holes within them would not necessarily give rise to giant objects. Therefore, they suggest that Alcyoneus is in a space region of low intermediate density, which may allow its expansion. And they still believe that Alcyoneus continues to grow.

*With information from ArXiv, astronomy and astrophysics