The Milky Way galaxy is known for its violent history filled with repeated collisions. Over the Universe’s 13.8-billion-year lifespan, the galaxy has subsumed multiple other galaxies and is continually merging with new smaller satellite galaxies. The galaxy is currently merging with the Sagittarius Dwarf Spheroidal Galaxy and the Large and Small Magellanic Clouds. However, a group of astronomers has now found out that the ones being subsumed now has eaten another galaxy in the past.
A team of astronomers led by Alessio Mucciarelli of the University of Bologna in Italy has found evidence that the Large Magellanic Cloud (LMC) is also a cannibal, which merged with another galaxy at some point in its past, which is yet to be learnt. According to the astronomers, the findings represent fascinating support for scientists’ understanding of how galaxies grow. The galaxies are believed to have grown by consuming other smaller galaxies.
Currently, the Magellanic Clouds orbit each other, and then together they orbit the larger Milky Way. The LMC is about twice the size of the Small Magellanic Cloud and has a total mass of up to 250 billion solar masses. Moreover, four to six small, ultra-faint galaxies have been associated with the LMC, which hints that the galaxy had many other smaller galaxies around it in the past.
Astronomers find proof on assembly history of galaxies
Astronomers in 2018 had found a small number of stars in the LMC orbit counter-clockwise to the grain, against the majority of the stellar flow. This was proof of a giant merger that took place between the galaxies in the ancient past. Now, the team led by Mucciarelli have found a globular cluster named NGC 2005, which comprise hundreds of thousands to millions of stars, tightly bound together by gravity into a spherical shape, with a dense concentration of stars in the centre.
The stars based on their same old age and chemical composition have been thought to be ‘fossils’ of the early Universe. This has led to hints unlocking the history of star formation. The Milky Way has around 150 such clusters, and the Large Magellanic Cloud has around 60 which powers the study that the galaxies have eaten smaller ones in the past.
Following the new finding, Mucciarelli and his colleagues have compared NGC 2005 to other such clusters and found that its chemical abundance ratios were wildly different from other clusters in the study. According to the researchers, NGC 2005 is the surviving witness of the ancient merger event that involved the Large Magellanic Cloud. The astronomers have claimed that the finding has opened a new way to investigate the assembly history of galaxies beyond the Milky Way.
Image: Twitter
The Milky Way galaxy is known for its violent history filled with repeated collisions. Over the Universe’s 13.8-billion-year lifespan, the galaxy has subsumed multiple other galaxies and is continually merging with new smaller satellite galaxies. The galaxy is currently merging with the Sagittarius Dwarf Spheroidal Galaxy and the Large and Small Magellanic Clouds. However, a group of astronomers has now found out that the ones being subsumed now has eaten another galaxy in the past. A team of astronomers led by Alessio Mucciarelli of the University of Bologna in Italy has found evidence that the Large Magellanic Cloud (LMC) is also a cannibal, which merged with another galaxy at some point in its past, which is yet to be learnt. According to the astronomers, the findings represent fascinating support for scientists’ understanding of how galaxies grow. The galaxies are believed to have grown by consuming other smaller galaxies. Currently, the Magellanic Clouds orbit each other, and then together they orbit the larger Milky Way. The LMC is about twice the size of the Small Magellanic Cloud and has a total mass of up to 250 billion solar masses. Moreover, four to six small, ultra-faint galaxies have been associated with the LMC, which hints that the galaxy had many other smaller galaxies around it in the past. Astronomers find proof on assembly history of galaxies Astronomers in 2018 had found a small number of stars in the LMC orbit counter-clockwise to the grain, against the majority of the stellar flow. This was proof of a giant merger that took place between the galaxies in the ancient past. Now, the team led by Mucciarelli have found a globular cluster named NGC 2005, which comprise hundreds of thousands to millions of stars, tightly bound together by gravity into a spherical shape, with a dense concentration of stars in the centre. The stars based on their same old age and chemical composition have been thought to be ‘fossils’ of the early Universe. This has led to hints unlocking the history of star formation. The Milky Way has around 150 such clusters, and the Large Magellanic Cloud has around 60 which powers the study that the galaxies have eaten smaller ones in the past. Following the new finding, Mucciarelli and his colleagues have compared NGC 2005 to other such clusters and found that its chemical abundance ratios were wildly different from other clusters in the study. According to the researchers, NGC 2005 is the surviving witness of the ancient merger event that involved the Large Magellanic Cloud. The astronomers have claimed that the finding has opened a new way to investigate the assembly history of galaxies beyond the Milky Way. Image: Twitter