Research

Our galaxy was not a flat disk, as previously thought.

The results of an international group studyAstronomers, published in the journal Nature Astronomy, say that our own Milky Way galaxy is not at all like a flat “pancake”, as it was considered earlier. Closer to the edges of the galaxy becomes more compressed or crumpled "accordion". Scientists believe that this discovery will force us to reconsider our current star maps.

Since we are inside the Milky Way, weunable to see the full shape of our galaxy. It's like sitting inside a submarine and trying to figure out the size of the ocean, scientists say. Therefore, we often compare our galaxy with the neighboring Andromeda galaxy. Maybe Andromeda is a little bigger than our Milky Way in size, but both galaxies belong to the spiral type and, in the opinion, astronomers have almost the same age.

During the new study of astrophysicsconfirmed that our galaxy does not look like a flat pancake or even the letter S, as previously shown maps of the distribution of hydrogen, and has a bizarre shape, whose edges are braided in an unusual crumpled and compressed spiral.

The observation of several thousand stars located in its outer regions helped confirm the unusual shape of our galaxy.

"It is very difficult to determine the distance from the Sun tothe outer parts of the Milky Way galactic disk, without having a clear idea of ​​how this disk actually looks like, ”comments Xiaodian Chen from the National Astronomical Observatory of the Chinese Academy of Sciences.

One of the methods to conduct suchcalculations associated with the observation of variable cepheid stars. The peculiarity of Cepheids is that their brightness first grows very smoothly and gradually, and then decreases as a result of internal processes inside their depths. The frequency and strength of these pulsations depend on the absolute brightness of the star, which allows astronomers to use them to measure distances in space, including how far different parts of the Milky Way are located from us.

The number of known Cepheids in the central and distantparts of the Milky Way are relatively small, which encourages astronomers to actively look for such stars in the hope of understanding how the core of the galaxy and the furthest regions are arranged. But this is difficult to do because of the dense accumulations of dust and gas surrounding these regions of the Milky Way. The WISE infrared space telescope helped solve the problem.

"We used infrared observations,conducted by the WISE Space Infrared Observatory, which helped “break through” dust and gas and determine the distance to Cepheids with an accuracy of less than 3-5 percent, which represents an unprecedented level according to current capabilities ” .

Using images from the WISE telescope, astronomerscalculated the exact distance and position of almost one and a half thousand variable stars and used them to compile a more accurate three-dimensional map 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 disk, rotating, pulls the outer ring behind it, which causes twisting.

Scientists add that the “harmonica” noted at the edges of the Milky Way is not observed in the same Andromeda, but is found among some other spiral galaxies discovered in the last half of the century.

The discovery of such an unusual form of our diskgalaxies, according to de grace and his colleagues, explains many oddities in the behavior of stars on its margins and will help to clarify their position, age and other properties.

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