The high -speed clouds are made of gases that travel much faster than the rotating plane of the Milky Way. Credit: Warwick Davis (Flickr, CC By-NC-SA 2.0)
Be careful, astronomers: there may be a dark galaxy in the midst of us.
In the research published today in Scientific progressThe researchers of the Chinese National Academy of Sciences have discovered that a rapid movement cloud near the Milky Way may not be a cloud at all, but rather a small galaxy made mostly in dark matters.
A dark galaxy
AC G185.0-11.5 is part of the larger AC-I complex, which is what astronomers call a high-speed cloud (HVC). These are tufts of hydrogen that move up to several hundred mph faster than the gas on the level of the Milky Way. The HVCs are believed to be materials that fall on the galaxy from the outside, perhaps by other galaxies torn from ours or even by the Ejecta lived by supernovae within our galaxy, jumped to vast distances and now finally establish themselves.
But while the authors examined the AC-I using the data of the Arecibo body now collected in Puerto Rico and the spherical radio of the opening of five hundred meters (fast) in Guizhou, China, they discovered a tuft inside, called AC G185.0-11.5, which showed properties more in line with a sequence of rotating disco-but a visible inside.
The galaxies in which there are few stars are called dark galaxies and astronomers believe they are so dark because there is very little material inside them to form stars. Instead, these objects are dominated by the dark matter, which interacts weakly only with normal matter, also called Barionic Matter. (The Barkian matter constitutes only 15 percent of the question in the universe, while the dark matter constitutes the other 85 percent.)
“We have not seen any formation of stars from the available optical data, therefore it is always dark,” says the co-author of the Ming Zhu studio, an astrophysicist at the Chinese National Academy of Sciences. In fact, Zhu says that AC G185.0-11.5 seems to contain 21 times more dark matter than normal matter.
Not a cloud
But how did the researchers determine that AC G185.0-11.5 is a galaxy?
The tribute came from the detection of the rotation in a group of material inside AC-I. The way the tuft moved, says Zhu: “reveals that gas is rotating [in] A structure similar to a disc. “In addition, Zhu adds,” there should be a dark matter inside to control the rotation “.
The team calculates that AC G185.0-11.5 contains about 300 million mass sun Suns, although there is a high degree of uncertainty.
Based on the mass and rotation of the galaxy, the researchers were also able to calculate its distance as about 900,000 light years, although the mass is so uncertain, this distance also contains a lot of uncertainty. But since it is notoriously difficult to measure the distances against HVC, this is a great improvement with respect to previous knowledge.
AC G185.0-11.5 is large enough to study with telescopes on the ground and terrestrial. Zhu says that observers like JWST could be used to detect if there are stars that shine inside, while the very large array could help you better imagine the galaxy record while rotating and possibly discern what is in the center.
Decipher the dark matter
The results should be taken with a grain of salt. To date, some dark candidate galaxies have not made the edge: they were found as normal gas clouds with some internal tidal interactions. And there are still several uncertainties in measurements.
But if AC G185.0-11.5 is confirmed as a dark galaxy, its proximity to the Milky Way could make it a perfect laboratory to better study the role of dark matter in galaxies, regardless of whether or not they are dominated. All galaxies contain dark matter, which interacts with Barionics through gravity. Astronomes have known since the 1960s that the seriousness of the dark matter affects the way in which the galaxies revolve by comparing the way in which they are expected to turn according to their question visible on how they Actually Move, the latter of which indicates that there is more matter than you can see.
Therefore, studying a mostly obscure galaxy could reveal more clearly the behavior and nature of this mysterious substance, better informing the research in our galaxy and beyond.
