A huge effort by a huge international team of scientists has yielded the most accurate map of all matter in the universe ever obtained.
Combining data from two large-scale surveys, the international collaboration will help determine not just the normal matter that makes up planets, stars, and dust, but where the universe does and does not hold all the junk. clarified. Black Holeis a galaxy, but dark matterTOO: A mysterious invisible mass that produces more gravity than normal matter can explain.
The resulting map shows where matter has gathered over the universe’s 13.8 billion year lifetime and will be a valuable reference for scientists trying to understand how the universe evolved. .
In fact, the results already show that the problem is not distributed as we thought, suggesting that there may be something missing in the current situation. standard model of cosmology.
According to the current model, big bang, all matter in the universe was condensed into a singularity. A single point of infinite density and extreme heat suddenly burst and released quarks, which rapidly combined to form a soup of protons, neutrons and nuclei. Hydrogen and helium atoms appeared hundreds of thousands of years later. From these the whole universe was made.
How these early atoms spread, cooled, coalesced, and formed stars, rocks, and dust is detective work based on what the universe around us looks like today. And one of the major clues we used is where all the matter is now.
But you can’t see it all. In fact, most of the matter in the universe (about 75%) is completely invisible to current detection methods.
It could only be detected indirectly, as it creates a gravitational field stronger than what should exist based on the amount of normal matter. This is manifested in phenomena such as galaxies rotating faster than they should, and in the quirks of the universe. gravitational lens effect.
If something in the universe has enough mass (say, a cluster of thousands of galaxies), the gravitational field around it will be strong enough to affect the curvature of spacetime itself.
This means that light passing through that region of space will distort and expand as it travels along a curved path. These lenses are also stronger than if they were made only by ordinary matter.
To map matter in the universe, researchers compared gravitational lensing data collected in two different surveys. dark energy research, data were collected at near-ultraviolet, visible, and near-infrared wavelengths.and the antarctic telescopeto collect data. cosmic microwave backgrounda faint trace of radiation left over from the Big Bang.
By cross-comparing these two datasets acquired by two different instruments, researchers can be more certain of their results.
“It acts like a cross-check, so it’s a much more robust measurement than using either one alone.” Astrophysicist Chihway Chang said: A professor at the University of Chicago, he was the first author of one of the three papers describing this study.
The first author of the other two papers is physicist Yuki Ohmori Kavli Institute for Cosmological Physics and Telescope Scientist at the University of Chicago Tim Abbott NOIRLab’s Cerro Tololo Inter-American Observatory.
Maps obtained based on galactic positions, galactic lensing, and cosmic microwave background lensing can be extrapolated to infer matter distribution in the universe.
This map can then be compared to models and simulations of the evolution of the universe to see if the observed distribution of matter matches theory.
The researchers performed several comparisons and found that the map closely matched the current model. But it’s not. There was a very slight difference between observations and predictions. The distribution of matter the researchers found is less clumpy and more evenly spaced than the model predicts.
This suggests that our cosmic model can use fine-tuning.
This is not so surprising. Between cosmological observations and theory, Missing a trick or twosomewhere; the team’s findings are consistent with previous research, but the more accurate and complete the data, the more likely these discrepancies can be resolved.
There is still work to be done. The findings are not yet conclusive. Adding research will help refine your map and validate (or refute) your team’s findings.
And of course, the map itself helps other scientists to independently investigate the universe’s mysterious and dark history.
This research Physical Review DThe three papers are available and can be found on the preprint server arXiv. here, hereWhen here.
