Sciencio.com

Almost all massive galaxies have at least one major merger, since the Universe was 6 billion years old, revealed the largest study on the form and structure to the present.

The reconstruction of how the galaxies have merged is an essential part of the understanding of their development.
But the study could also help in the decades of intense debate over whether the episodes of Star Formation, known as star bursts, triggered by large galactic mergers or processes within the individual galaxies.

The study uses data from the Hubble Space Telescope to a massive 21,902 galaxies as they appear when the universe - now about 13.7 million years ago - 5.2 million to 11.2 billion years ago.

More mergers in the galaxy with an asymmetric clumpy appearance, and on the basis of an analysis of these characteristics, Christopher Conselice astrophysicist at the University of Nottingham, UK, and his colleagues found proof of at least 2000 merger of that era.

Scientist discovered a close correlation between the time of the merger and the Starburst episodes.

Mr Conselice added that a sharp decline in concentration, when the universe was about 7 million years ago, with a decrease in the time before stars.

Since each of the galaxy was photographed in a moment in its development, the team extrapolated their findings to the conclusion that almost all galaxies have undergone  merger by the present day.