A team of astronomers captures the beginning of a 'War ... - I is interesting

Herschel space observatory of ESA has been an unusual encounter between two gas-rich galaxies presents the solution to the old problem of how large galaxies formed in the early universe passive.

Most large galaxies fall into one of two categories: the spiral galaxies , like our Milky Way, with a lot of gas and star formation activity, or elliptical galaxies , gas-poor, populated by old red stars and cold, with little sign of activity.

For a long time it was assumed that large elliptical galaxies we see in the universe today formed slowly merging through gravitational smaller galaxies. This hypothesis suggested that the gas in these galaxies would become progressively colder low-mass stars, to exhaust all its reserves, leaving a galaxy ‘red and dead’ .

When in the last decade it was discovered that large elliptical galaxies were able to form in the first 3-4 billion year history of the Universe, this hypothesis staggered. Somehow, within a very short time in cosmological terms, these galaxies had been able to quickly gather a lot of stars and then had ‘off’.

One possible explanation is that two spiral galaxies collide and be merged, resulting in a large elliptical galaxy. The collision would unleash a massive outbreak of star formation that quickly exhaust all gas reserves. With Herschel observations, a team of astronomers has been able to capture beginning of this process between two massive galaxies when the Universe was barely 3,000 million years .

This pair of galaxies was initially identified in the Herschel data as a single source, dubbed HXMM01. A closer look revealed that it was actually two galaxies, each with a stellar mass equal to 100,000 times the Sun and with an equivalent amount of gas.

galaxies are linked by a bridge of gas , indicating that you are merging. “This monstrous system interacting galaxies is the most efficient factory stars ever detected in the early Universe , when he barely had 3,000 million years,” says Hai went to the University of California, Irvine, United States, author of the study published in Nature.

“The system HXMM01 is very special, not only because of its large mass and intense star formation activity, but also because it is in an intermediate stage and fundamental the merger process, which will help us improve the current models describing the formation and evolution of galaxies “, adds Asantha Cooray, co-author of the publication and also a professor at the University of California, Irvine.

The beginning of melting has triggered a frantic star formation activity, reaching a rate equivalent to about 2,000 stars like our Sun per year . In comparison, a galaxy like the Milky Way form only current equivalent to a Sun every year.