An invisible force affects our universe. We can not see it and we can not see it – but we can see how it interacts gravitationally with things can see and recognize how z. B. light.
Now an international team of astronomers has used one of the world's most powerful telescopes to analyze this effect in 10 million galaxies related to Einstein's general theory of relativity. The result? The most comprehensive map of dark matter in the history of the universe.
The peer review is ongoing, but the map has suggested something unexpected – that dark matter structures may develop more slowly than previously thought.
"If further evidence shows that we are definitely correct, it suggests that something is missing from our current understanding of the Standard Model and General Theory of Relativity," said physicist Chiaki Hikage of the Kavli Institute of Physics and Mathematics of the Universe.
We do not know what dark matter is. What we do know is that the effects of gravity that we see in the universe can not be explained by observable matter alone. For example, the rotational speed of galaxies would be quite different if it relied solely on gravity from the observable mass.
We also know that gravity can bend the light path as we see it with gravitational lenses. This effect can also be used to map dark matter. When subtracting the gravitational effect of visible matter, only the gravitational effect of dark matter remains.
This is a common way to find Dark Matter, and it is also the Hikage team. They used the 870-megapixel hyper-suprime cam of the 8.2-meter Subaru telescope to reach galaxies billions of light-years away.
Because their light took so long to reach us, we see them as they existed billions of years ago, which means that the map covers a large area of the universe's history and astronomers can observe how dark matter crosses over Billions of people has developed years.
The resulting 3D map shows the lumpy structure of the dark matter of the Universe, which is consistent with the results of previous investigations – with the exception of the speed at which the structures develop. According to this new map, this is slower than predicted by the previous results.
Not much, but enough to turn out to be weird. That is, the jury is not yet clear what it means. This could indicate that something is missing in the standard model, which would be quite amazing. or it could indicate a statistical fluctuation in the data.
It might take a while to figure it out. The team has been working on this project since 2014, using only observations from the first year or 11 percent of the survey of Hyper Suprime-Cam that are ongoing. The photography will be completed in the course of the year 2020.
So let's not be too exciting – there is still a lot of mother ship load to do. But it is still a fascinating result, and we expect more information with bated breath.
"With a little more work, we may be able to find something concrete," said Hikage. "This is a big motivation factor for me."
The research of the team was included in the Publication of the Astronomical Society of Japan, and can be fully read on the pre-print server arXiv.