Our galaxy was not a flat disk, as previously thought
Results of the study of the international group of astronomers published in the journal Nature Astronomy, suggests that our own Milky Way galaxy does not look like a flat "pancake" as previously thought. Closer to the edge of the galaxy becomes more on compressed or wrinkled "harmonica". Scientists believe that this discovery will force us to reconsider our current star maps.
Since we are inside the Milky Way, we are not able to see the overall shape of our galaxy. It's like sitting inside a submarine and try to figure out the size of the ocean, the scientists say. Therefore, we often compare our galaxy with the neighboring Andromeda galaxy. Maybe Andromeda in size and slightly larger than our Milky Way, but both galaxies are spiral type and, according to astronomers have almost the same age.
In the new study, astrophysicists have confirmed that our galaxy is not like a flat pancake or even the letters S, as it was stated previously created maps of the distribution of hydrogen and has a bizarre shape whose edge braided in an unusual crumpled and compressed spiral.
Confirm the unusual shape of our galaxy helped the observation of several thousand stars, located in its outer regions.
"It is very difficult to determine the distance from the Sun to the outer parts of the Milky Way galactic disk, without having a clear idea of how to actually look like this drive," - commented Syaodian Chen from the National Astronomical Observatory, Chinese Academy of Sciences.
One of the methods, allowing to carry out such calculations, related to the observation of variable stars, Cepheids. Cepheid feature in that their brightness is initially very smoothly and gradually increases and then decreases as a result of internal processes within their interior. The frequency and strength of these fluctuations depend on the absolute brightness of the light, allowing astronomers use them to measure distances in space, including to examine how far away different parts of the Milky Way from us.
The number of known Cepheids in the central and distal portions of the Milky Way is relatively small, which encourages astronomers actively look like a star in the hope of understanding the structure of the nucleus of the galaxy and the most remote regions. But this is difficult because of dense dust and gas surrounding these regions of the Milky Way. To resolve the issue helped infrared space telescope WISE.
"We used data from infrared observations made infrared space observatory, the WISE, which has helped to" make it "through the dust and gas, and to determine the distance to the Cepheids with an error of less than 3-5 percent, according to the current capabilities represents an unprecedented level", - says Richard de Grace Macquarie University in Sydney (Australia).
Using images from WISE telescope, astronomers have calculated the precise distance and position of almost a thousand variable stars and used them to compile a more accurate three-dimensional map of the Milky Way arms. The researchers suggest that the detection of the curvature at the edges of the galaxy could be explained by the fact that the inner part of the disk rotates, pulls the outer ring, causing twisting.
Scientists are added, as noted at the edges of the Milky Way "accordion" is not found in the same Andromeda, but common among some of the other spiral galaxies discovered in the last half century.
Opening such an unusual form of the disk of our galaxy, according to de Grace and his colleagues explain the many oddities in the behavior of the stars on its outskirts and help clarify their status, age, and other properties.
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