In an impressive example of a multi-mission astronomy, measurements of the NASA / ESA Space Hubble telescope and the ESA Gaia collection were combined to improve the mass estimate of our Milky Way home galaxy: 1.5 trillion solar masses.
Plus the Milky Way is one of the most basic measurements that astronomers can do about our galactic home. However, despite decades of intense effort, even the best estimates available in the Milky Dairy mass disagree with wildlife. Now, by combining new Gaia and European Space Agency (ESA) mission data with observations made with NASA / NASA Space Hubble Telescope, astronomers have found that the Milky Way weighs in approximately 1.5 trillion solar masses from within a radius of 129 000 light-up of the galactic center.
Previous estimates of the width of the Llaethog Road ranged from 500 billion to 3 trillion times of mass of the Sun. This major uncertainty arose mainly from the different methods used to measure the distribution of a dark matter – which accounts for about 90% of the galaxy mass.
The impression of this artist shows a computer model of the Milky Way and the correct location of the globally clusters used in this study. Scientists used the measured speeds of these 44 globally clusters to determine the mass volume of the Milky Way, our cosmic home. Credit: ESA / Hubble, NASA, L. Calçada, M.Kormesser
"We can not find a dark matter directly," said Laura Watkins (Southern European Observatory, Germany), which led to the performing team and the analysis. "That's what leads to the current uncertainty in the Milk Milk mass – you can not accurately measure what you can not see!"
Given the stimulating nature of the dark matter, the team had to use a smart way to press the Llaethog Road, which was dependent on measuring the speed of globic clusters – intense star clusters that overlap bone disks the galaxy in large distances.
"There is a more massive galaxy, whose clusters faster move away by removing its severity" explains N. Wyn Evans (University of Cambridge, UK). "Most of the previous measurements have found the speed of cluster approaching or coming from the Earth, that is the speed along our line of sight. However, we were also able to measure the side of the clusters side, which can be calculated as a whole, and as a result of the galactic mass. "
The group used the release of Gaia's second data as the basis of its study. Gaia was designed to create a detailed three dimensional map of astronomical objects through the Ffordd Llaethog and to track their proposals. Its second data release includes measurements of globally clusters as far as 65,000 light years of Earth.
"Global clusters stretch out to a large distance, so it's considered as the best tracker servers users to measure the mass of our galaxy," said Tony Sohn (Institute of Space Telescope Science, USA), which led to the Hubble measurements.
Measures from NASA / NASA Space Hubble telescope and the Gaia ESA collection were combined to improve its approximation of our Milky Way home galaxy: 1.5 trillion solar bays.
The team combined these data with Hubble sensitivity and restless observations. Hubble's comments allowed the clusters of weak and remote pools, up to 130 000 light years of Earth, to be added to the study. Because Hubble has been watching some of these objects for a decade, it was also possible to correctly track the speed of these clusters.
"We were fortunate to have such a great combination of data," explained Roeland P. van der Marel (Institute of Space Telescope Science, USA). "By combining the Gaia measurements of 34 clutch clusters with 12 distant clusters from Hubble, we could determine the mass of the Milky Way in a way that would be impossible without both these space telescope."
So far, knowing the exact mass of the Milky Way has not presented a problem for attempts to answer many cosmological questions. The content of a dark disease and distribution issue is mainly related to the formation and growth of structures in the Universe. Determining the mass for the Milky Way gives us a clearer understanding of where our galaxy sits in a cosmological context.
Paper: Evidence for Intermediate Massive Milky Way of Globular Halo Cluster Proposals DR2 Gaia