Take a tripper to one of Disney ’s resorts in California or Florida , and you could find yourself at Galaxy ’s Edge . Well , Star Wars’Galaxy Edgeat least . The edge of our galaxy is far , far out . A new estimate , featured on the pre - print websitearXiv , has found that the Milky Way spans approximately 1.9 million calorie-free - twelvemonth in diameter , more than seven times wider than late approximation .
Last class , GAIA mapping data provided a fierce disc diam of 258,000 unaccented - geezerhood . However , astronomers acknowledged that there was a great big problem lallygag in the out grasp of the galaxy that makes these estimations problematic . obscure subject .
A vasthalo of dark matterappears to engross the visible thing in the Milky Way ’s disk and reach far beyond it as well . give that we ca n’t see it , the Milky Way ’s dark halo is a pretty surd thing to quantify . However , astronomers can infer its presence by studying the motion of cosmic objective around it , which is exactly how this latest estimate come about .
Dr Alis Deason , from Durham University , and her co-worker produced computer simulations of the sorry matter gloriole of Galax urceolata of a similar mint to the Milky Way . Not only were these mapped in closing off but also in situations where the galax was near to another – analogous to the Milky Way and our close gargantuan neighbor Andromeda . In these representative , the velocities of other small nearby galaxies , included in the pretense to mimic the dwarf galaxies around the Milky Way in theLocal Group , dropped sharply at the bound of the gargantuan galaxy ’s dark ring .
step away from the simulations , the squad looked at scope observations of the literal midget galaxies in the Local Group around our galax and find a like drop in their radiate velocity , indicating the Milky Way ’s dark ring boundary . This occurred at around 950,000 light - long time from our galaxy ’s center – 35 times farther from the astronomical center than the Sun is .
“ In many analytic thinking of the Milky Way halo its outer boundary is a fundamental constraint , ” wrote the report author ’s in theirpaper . “ Often the pick is immanent , but as we have argue , it is preferable to set a physically and/or observationally motivated outer edge . ”
Going forward , the team hope that their data can help others yield more robust and accurate measurements of the edge of the Milky Way , as well as potentially help the uncovering of extra little galaxies nearby .
[ H / T : ScienceAlertandScienceNews ]
