Scientists from an international team used data from the largest telescopes to study galaxies about 10 billion light years from Earth. They detected supermassive black holes inside them.
The Milky Way is filled with stars of all ages, including those that are just emerging. In other galaxies, however, called elliptical (due to their shape), all the stars are old and of a similar age, which indicates that they formed a lot of stars in the early stages of their existence, but that period suddenly ended, the scientists explained. SOKENDAI University of Japan.
It is not known why this happened. According to one possibility, supermassive black holes were influencing gas in some galaxies, disrupting new star formation.
Recall that a supermassive black hole is a black hole with a mass of millions or even billions of solar masses.
They studied galaxies that existed 10 billion years ago
To test their theory, researchers at SOKENDAI University and colleagues at other centers looked at old galaxies that existed about 10 billion years ago. This means that light from an object 10 billion light years away had to travel 10 billion years to reach Earth. For this reason, their signal is very weak and the images are not clear.
However, a team of researchers has found a way to deal with it. To study galaxies 9.5-12.5 billion light-years away, data from the Cosmic Evolution Survey (COSMOS) project was used. It combines data from the largest telescopes, including the Atacama Large Millimeter / submillimeter Array (ALMA) and the Subaru Telescope. It also includes research in the field of radio, infrared, visible and X-rays.
The image below in the center shows an image from the COSMOS project surrounded by images of the most distant galaxies under study.
Supermassive black holes in dying galaxies
Using observations in visible and infrared light, scientists identified two groups of galaxies. Among them, there were those in which star formation continued and those in which stars stopped forming. Researchers used radio and X-ray analysis to detect supermassive black holes. However, the signal strength of individual galaxies relative to the perturbation was too low due to the distance, so the team of scientists combined data from multiple galaxies to create images of an ‘average’ galaxy.
The images obtained confirm both the high strength of radio waves and X-rays emitted by galaxies in which star formation had previously stopped, indicating the presence of supermassive black holes, the scientists explain. The emissions were also too strong to be explained by the presence of stars. This is the first time such signals have been detected in galaxies more than 10 billion light years away.
These findings suggest that the abrupt end of star formation in the early Universe coincided with increased activity in supermassive black holes, as stated in a study published last month. The team of scientists notes that more research is needed to establish the details of this relationship.
PAP, nao.ac.jp, tvnmeteo.pl
Main photo source: DRINK