New discoveries have deepened the mystery of galaxies without dark matter.
In the galaxy named AGC 114905, 250 million light years, astronomers cannot find a trace of mysterious items, even after 40 hours of detailed observations and subsequent analysis.
As a result, to be published in the monthly notification of the Kingdom astronomy and is available on the Preprint Arxiv server, increasing cases for galaxies that are mysteriously less in dark matter, although it is very important for the evolutionary model of our galaxy.
“This, of course, what we think and hope for confirming our previous measurements,” said Astronomer Pavel Mancera Piña from the University of Groningen and Astron in the Netherlands.
“But now the problem is still that the theory predicts that there must be dark matter on AGC 114905, but our observations say no. In fact, the difference between theory and observation is only bigger.”
Dark matter is one of the big mysteries of the universe. We don’t know what it is because we can’t detect it directly, but we know there are some masses out there that cause various effects in the universe that cannot be explained by normal problems.
Stars, for example, orbit their galaxies at a higher speed than that can be explained by the normal gravitational field. How to walk the light when traveling through a massive gravity in the intergalactic space is another thing.
Astronomers believe that dark matter helps the form of galaxies. There is an invisible web material that includes the universe, and the gravity it produces helps normal problems come together to the galaxy. And, according to our model, dark matter also helps this galaxy remains together – a kind of cosmic binding agency.
But astronomers have found guidance galaxies without dark matter in recent years, contrary to how we believe the universe exists. So, when Mancera Piña and his colleagues found six galaxies seemed to be without dark matter, explained in the 2019 paper, they decided to take a closer look.
AGC 114905 is what we call Ultra Dwarfuse Galaxies. It’s about the size of the Milky Way, but a lot, much less luminous, containing a few fewer stars – about a thousand times less. Because they have so few normal problems, it is estimated that this galaxy must be united by dark matter.
So the researchers took a closer look at AGC 114905 using a very large NRAO array in New Mexico, obtaining a total of 40-hour observation data at a much higher spatial resolution. Then, they carefully plan a galaxy rotation curve – orbital speed object on AGC 114905, plotted the distance from the center of the galaxy.
This is one of the most common methods to calculate the amount of dark matter in the galaxy: Objects that orbit too quickly can be explained by adding dark matter, and the amount of dark matter affects additional orbital speeds.
But the AGC 114905 rotation curve does not require the presence of dark matter. This can be explained only with the number of normal problems. This means that the amount of dark matter in the galaxy seems to be ignored.
And this caused pickled volumes because there was no explanation because of the lack of appropriate dark matter. One explanation, for example, is if the massive galaxies nearby have abandoned AGC 114905 from the dark matter, as it seems to occur in other diffuse galaxies found do not have dark matter, DF4.
“But nothing,” said Mancera Piña. “And within the most famous Galaxy formation framework, called a cold dark material model, we must introduce extreme parameter values that far exceed the usual range. Also, with the dynamics of Newton are modified, the theory of cold alternatives, we cannot reproduce Gas movement in the galaxy. “
In the case of another galaxy with abnormal dark matter, we can only misread distance. But the distance to AGC 114905, the researchers said, well limited.
Maybe, the researchers recognize that the estimates of the angle of observation can die; It can explain the lack of dark problems. But it must die, they said, with a large margin.
In addition, all six galaxies from their initial studies all show the same behavior, in different tendencies. This shows that behavior is not the result of systematic errors, they said. They are currently committing detailed follow-up on the second ultra-diffuse galaxy to try and reach the bottom.
If confirmed, their findings can have very interesting implications for our understanding of the evolution of the galaxy.
“We have strengthened and clarified previous results in natural nature and dynamics of gas-rich ultra-diffuse galaxies. However, their origin and the right evolutionary path remains largely a mystery,” the researchers wrote on their paper.
This work has also shown that gas-rich ultrhfuse galaxies are a promising population to study dark matter, because they have the potential to provide material instructions to understand their nature. “
This research will appear in the monthly notification of the royal astronomy and is available at Arxiv.