Collision or merger of two galaxies, mostly one large galaxy and several small ones is common in the Universe. Astronomers have also observed some major mergers among the pair of galaxy similar in size.
But, US team of astronomers observed one of the biggest galaxy collisions ever using NASA’s Spitzer and Chandra Space Telescope. Spitzer spotted four-way merger in a giant galaxy cluster, called CL0958+4702, located nearly five billion light years away.
In one of the largest cosmic smash-ups ever, Spitzer first observed a massive fan shaped plume of light coming out of a gathering of four blob-shaped, or elliptical, galaxies. Three of the galaxies equaled our own Milky Way in size, while the fourth was found three times as big.
In this merger, billions of old stars flung out creating a huge plume. At the end of this ongoing collision, all the four galaxies will merge to create the biggest galaxy, up to 10 times as big as our Milky Way, in the Universe.
Co-author Kenneth Rines, of the Harvard-Smithsonian Center for Astrophysics, in Cambridge, US, said:
Most of the galaxy mergers we already knew about are like compact cars crashing together, what we have here is like four sand trucks smashing together, flinging sand everywhere. It’s the first one that I know about. So far, nobody has written to me to say they’ve found another four-way merger.
The plume contained incredible amount of material tossed up and there were more stars in the plume than there are in our Milky Way. Later on, the galaxy will pull back half of these stars inside the boarder of giant left.
This observation, helped astronomers, explains a puzzle regarding the formation of new stars in such mergers. Astronomers are of the opinion that there are two kind of merger, gas-rich and gas-poor mergers. Stars are formed in the gas-rich mergers while gas-poor mergers end without any new birth. This new quadruple merger was found gas-poor hence involved no star formation and contained only old stars.
The team used two ground-based observatories, MMT and WIYN in Tucson, Arizona, along with Spitzer and Chandra to analyze this rare moment.
Image Credit: Wikimedia
Via: BBC
