It seems that a team of astronomers from the United Kingdom has revealed the process of formation of galaxies similar to the Milky Way, which occurred through the collision of different galaxies. Although they are considered among the largest objects in the universe, the formation of galaxies is an age-old question, and still without exact answers.
Galaxies in the nearby universe are quite diverse in shape and size: some, including the Milky Way, are spirals made up of more than a trillion stars, while others are large groups of stars in a ball or oval structure, without specific patterns. At the moment, the history of these large systems is unknown.
Galaxies can gain mass through mergers that occur when two of them collide and form a new galaxy. The merger process has been known for decades, but its role in the massive clumps seen in galaxies today remains unclear.
So, with that in mind, the authors analyzed how galaxies formed in the last 10 billion years. They worked with those who are in “pairs” who will, within a few billion years, merge and form new systems. By analyzing it during the fusion process, the study determined the history of its formation, with direct measurements of the process.
The authors conclude that mergers are one of the most important ways to form new galaxies. On average, the most massive galaxies in the past 10 billion years go through roughly three processes of merging with other galaxies, leaving more than twice the mass at the end of the process.
“This also indicates that the Milky Way has undergone at least one of these important mergers throughout history, which radically changed its shape and formation history,” explained Christopher Konsilis, lead author of the study. “Mortitions, such as those in this study, lead to star formation, which can be an original star formation event like the Sun and even the matter that feeds central black holes,” he said.
The article with the results of the study was published in the journal Astrophysical Journal.
source: Astrophysical Journal; Across: University of Manchester
