Astronomy: Milky Way's neighboring galaxy is apparently being torn apart
The Small and Large Magellanic Clouds are well researched due to their proximity. The neighboring galaxies of our Milky Way still have surprises in store.
The Small and Large Maggellanic Clouds (center right) next to the Milky Way above the Very Large Telescope
(Image: ESO/G. HĂĽdepohl (atacamaphoto.com))
A Japanese research group has found evidence that a galaxy in the immediate vicinity of our Milky Way is being torn apart by its larger companion and, unexpectedly, does not revolve around itself. This was announced by Nagoya University. The galaxies in question are the Small and Large Magellanic Clouds, both of which are less than 200,000 light years away from our home galaxy. A precise measurement of the movement of thousands of stars in the smaller of the two galaxies revealed that they are moving away from each other in opposite directions. This is due to the Large Magellanic Cloud, which is tearing apart the smaller galaxy.
An error was initially suspected
(Image:Â Satoya Nakano)
The team identified and measured a total of around 7000 individual stars in the Small Magellanic Cloud. These are mainly stars that are significantly more massive than our sun and are only a few million years old. The team has determined that a whole series of them are approaching the Large Magellanic Cloud, while others are moving away from it. This was unexpected, explains research leader Kengo Tachihara: "When we got the first results, we suspected an error in our analysis." However, when the team then made sure that the results were unquestionable, they were very surprised.
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The measurements also revealed that the massive stars in the galaxy do not rotate around a center. This suggests that the interstellar gas from which they were formed does not rotate either. If this is confirmed, assumptions about the mass and history of interaction with the Milky Way and the Large Magellanic Cloud will have to be revised. This could change our entire understanding of the history of the three galaxies, says the team. Because they also serve as a model for the interaction between galaxies, especially in the early universe, the consequences of the discovery could go even further. The analysis is now presented in the scientific journal The Astrophysical Journal Supplement Series.
(mho)
