Experts: Unprecedented galaxy collision was worse than train wreck in early universe


    Experts and astronomers are of the view that unprecedented galaxy collision was worse than train wreck in early universe and these galaxies were far bigger than anything astronomers have watched before

    In an event that could possibly help to unravel the mystery behind the birth of the universe, two distant galaxies sped up to cover 1.5 billion years of time to become one. This rare event of a massive and rare merging of two galaxies was captured by the Herschel space observatory, a joint collaboration between European Space Agency mission and NASA.

    It is believed that eventually both the galaxies would settle down to form one super-giant elliptical galaxy. The study that is published in the May 22 online issue of Nature, clearly suggest that massive mergers are responsible for the giant elliptical galaxies.

    The galaxies called HXMM01 are located about 11 billion light-years from Earth, during a time when our universe was about 3 billion years old. When the pictures were initially beamed back home by the Herschel the astronomers thought the two galaxies were just warped, mirror images of one galaxy as lensed galaxies are fairly common in astronomy and occur when the gravity from a foreground galaxy bends the light from a more distant object. However, following a closer examination, the team realized that it was rather a massive galaxy merger.

    Subsequently it was also found that the merging galaxies are churning out the equivalent of 2,000 stars a year which is much higher that the Milky Way that produces about two to three stars a year. The total number of stars in both colliding galaxies averages out to about 400 billion.

    Speaking about the findings,  Hai Fu, of the University of California at Irvine, who is lead author of a new study describing the results, said: “We’re looking at a younger phase in the life of these galaxies — an adolescent burst of activity that won’t last very long. These merging galaxies are bursting with new stars and completely hidden by dust. Without Herschel’s far-infrared detectors, we wouldn’t have been able to see through the dust to the action taking place behind.”

    It is pertinent to mention here that the follow-up studies undertaken by other telescopes including NASA’s Hubble Space Telescope and Spitzer Space Telescope, have given indications of the two faraway galaxies intertwined and furiously making stars. In fact several telescopes have teamed up to discover a rare and massive merging of two galaxies that took place when the universe was just 3 billion years old.

    It may be noted that mergers are fairly common in the cosmos, but this particular event is unusual because of the prolific amounts of gas and star formation, and the sheer size of the merger at such a distant epoch. The results produced by the present merger have gone against the more popular model explaining how the biggest galaxies arise: through minor acquisitions of small galaxies.

    Herschel that became operational operated four years ago was designed to primarily see the longest-wavelength infrared light. Recently it ran out of the liquid coolant needed to chill its delicate infrared instruments, marking the end of its mission in space. However, the astronomers are still analyzing the data delivered by Herschel to unearth further discoveries.