press a galaxy is not a job you might encounter every day , but it is often quite the job for stargazer . The mass of a galaxy is significant for derive certain properties , and current method have a lot of uncertainty .
A new method is now being suggest to measure the mass of a wandflower , in particular our own . investigator from the University of Arizona and the University of Cambridge have tried to work out the problem by using the littler galaxies border the Milky Way as a means to figure its mass . Their efforts are reported inThe Astrophysical Journal .
These orbiter galaxies revolve the Milky Way , so the mass of our galax powerfully affects their motion . Usually , researcher use the artificial satellite beetleweed ' side and velocity to make the volume estimation , but this enquiry team used a related but unlike quantity : angular impulse . Since the extragalactic nebula follow an elliptical orbit , their speed will be more or less different look on if they are cheeseparing or further away . angulate momentum is untouched .
" Think of a flesh skater doing a pirouette , " extend writer Ekta Patel , from the University of Arizona , said in astatement . " As she draws in her coat of arms , she spins faster . In other words , her speed modification , but her angular momentum stays the same over the whole length of her enactment . "
The squad calculated the full three - dimensional motion of 50 satellite of the Milky Way and combined that entropy with statistical models and simulations . They used virtual world with 20,000 “ master of ceremonies galaxies ” as proxy for the Milky Way . These were surrounded by 90,000 satellite galaxies . This approach helped them estimate the wad of the Milky Way to be 960 billion times the flock of the Sun . The team claim that this method acting has less uncertainty compared toprevious estimatesof the Milky Way ’s mass .
As fresh observation tower come online , more and more radical - wispy galaxies that surround the Milky Way become have it off to astronomers . The team go for to use this data to make more racy mensuration of the hatful of the Milky Way and to canvas properties like the dark subject depicted object of our galaxy .
" Our method acting allows us to take advantage of measurements of the pep pill of multiple satellite galaxies at the same time to get an solvent for what cold dark thing possibility would predict for the muckle of the Milky Way ’s halo in a robust way , " co - author Gurtina Besla added . " It is absolutely suited to take vantage of the current rapid maturation in both data-based datasets and numerical capabilities . "
This research was presented at the 232nd confluence of the American Astronomical Society in Denver .
