The results of the study by an international team of astronomers, published in the journal Nature Astronomy, saying that our home galaxy the milky Way is not like a flat “pancake”, as was previously assumed. Closer to the edges of the galaxy becomes more compressed or crumpled in “accordion”. Scientists believe that this discovery will force us to reevaluate our current star charts.
Since we are inside the milky Way, we are not able to see the full shape of our galaxy. It’s like sitting inside a submarine and try to figure out the dimensions of the ocean, scientists say. Therefore, we often compare our galaxy with the neighboring Andromeda galaxy. Maybe Andromeda in size and a little more of our milky Way, both galaxies belong to the spiral type and, in the opinion of 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 letter S, as indicate previously mapped the distribution of hydrogen, and has a quaint shape, whose edges braided in unusual crumpled and compressed spiral.
To confirm the unusual shape of our galaxy helped several thousands of stars located in its outer regions.
“It is very difficult to determine the distance from the Sun to the outer parts of the galactic disk of the milky way, without having a clear idea of how actually looks like this CD,” says Saadian Chen National astronomical Observatory, Chinese Academy of Sciences.
One of the methods to carry out such calculations is associated with the observation of variable stars-Cepheids. Feature of Cepheids is that their brightness at first very slowly and gradually increases and then decreases as a result of internal processes within their depths. The frequency and strength of these pulsations depend on the absolute brightness of a star, which allows astronomers to use them to measure distances in space, and to explore how far away from us the different parts of the milky Way.
The number of known Cepheids in the Central and distant parts of the milky Way is relatively small, which encourages astronomers to actively search for such stars in order to understand how the core of the galaxy and the most distant regions. But to make it difficult because of the dense clusters of dust and gas surrounding these regions of the milky Way. To solve the issue helped the infrared space telescope WISE.
“We used data from infrared observations by the infrared space Observatory WISE, which helped to “break” through the dust and gas and to determine the distance to Cepheids with an error of less than 3-5 per cent, according to the current capabilities represents an unprecedented level,” commented Richard de grace from Macquarie University in Sydney (Australia).
Using images from the WISE telescope, astronomers have calculated the precise distance and position almost a thousand variable stars and used them to produce a more accurate three-dimensional maps of the sleeves of the milky Way. The researchers suggest that the detected curvature at the edges of the galaxy can be explained by the fact that the inner part of the disc rotates and pulls the outer ring that causes twisting.
The scientists added that the note on the edges of the milky Way “self” is not observed in the same Andromeda, but is found among some other spiral galaxies, open in the last half century.
The opening of such unusual shape of the disk of our galaxy, according to de Grace and his colleagues, explains many of the strange behavior of the stars in its outskirts and will help to clarify their status, age and other properties.
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