The universe is largely anisotropic, with new studies indicating it. Hundreds of galaxy clusters of space-based X-ray observations suggest that the universe may be different depending on how astronomers see it. The study appears in the journal Astronomy and Astrophysics. This full sky map represents four of the hundreds of galaxy clusters that were analyzed to test whether the universe is basically the same in all directions.
Image from NASA / CXC / Bonn / K University. Migakas et al. / M. Weiss.. “One of the pillars of cosmology is that the universe is isotropic, which means the same thing in all directions. Our work suggests that there may be cracks in that pillar,” said Dr. Constantino Migakas, professor at the University of Bonn..Astronomer
Astronomers generally agree that after the Big Bang, the universe has continuously expanded. A common analogy is that this expansion is like a loaf of raisin bread. Like a piece of bread, the raisins (representing cosmic objects like galaxies and galaxy clusters) move away from each other as all the bread (representing space) expands.
With a homogeneous mixture, the expansion must be the same in all directions, as it should be with an isotropic universe. But these new results may not be compatible with that image. “Based on our cluster observations, we may have found how fast the Universe is expanding, depending on how we look,” said Dr. Gerrit Schällenberger.
An astronomer at the Center for Astrophysics at Harvard and the Smithsonian. “This is one of the most basic underlying assumptions that we use today in cosmology.” Astronomers have previously conducted various tests on whether the Universe is the same in all directions.
These included the use of optical observations of exploding stars and the infrared study of galaxies. Some of these previous efforts have offered possible evidence that the universe is not isotropic, and others is not. The latest test uses powerful, novel and independent technology.
This is due to the temperature of the hot gas permeating a galaxy cluster and the amount of X-rays it produces, known as the capital’s X-ray luminosity. The higher the temperature of a gas in a group, the higher the luminosity of X-rays. Once the cluster gas temperature is measured, the luminosity of X-rays can be estimated.
This method is independent of the quantities in the universe, including the rate of expansion of the universe. Once they estimate the X-ray optics of their groups using this technique, Drs. Migakas, Dr. Schenlenberger, and their colleagues calculated optics using a different method, which is based on the volume of the universe, including the rate of expansion of the universe.
Astronomers used a sample of 313 galaxy clusters for their analysis, which saw 237 clusters by NASA’s Lunar X-ray Observatory, with a total exposure of 191 days, and a total of 35 days by the XMM-Newton spacecraft. from ESA. Together 76 observations were made…Science & Technology.
They also combined their sample of galaxy clusters with two other large X-ray samples using data from XMM-Newton and the Japan-US Advanced Cosmology and Astrophysics Satellite. USA (ASCA), giving a total of 842 different galaxy clusters. Become
The results gave the researchers a clear rate of expansion across the sky, revealing that the universe seems to be moving away from us faster in some directions than in others. They also compared their findings with studies from other groups that have indicated a lack of isotropy using various techniques.
They found a good deal towards the lowest expansion rate. Scientists have put forward two possible explanations for their results, including cosmology. One of these explanations is that large groups of galaxies can grow together, but not because of cosmic expansion.
For example, it is possible that some adjacent clusters are being pulled in the same direction by the gravity of the clusters of other galaxy clusters. If the speed is fast enough, it can cause errors when estimating the light of the groups. Such correlated movements give different rates of expansion in different directions.
Astronomers have observed similar effects with relatively close galaxies, typically less than 850 million light-years away, where the mutual gravitational pull is known to control the movement of objects. However, the authors expected that the expansion of the universe would dominate the movement of groups over great distances of up to 5 billion light-years in this new study.
A second possible explanation is that the universe is not really the same in all directions. An intriguing reason may be that dark energy, the mysterious force that is accelerating the expansion of the universe, is not the same. In other words, X-rays can show that dark energy is stronger in some parts of the universe than in others.
Which can lead to different rates of expansion. An astronomer from the University of Bonn, Drs. Thomas Riprich said: “It would be the same as if the yeast in the bread did not mix uniformly, causing it to spread rapidly in some places.” It would be remarkable if the deep energy is in different energies in different parts of the universe.
However, it would take a lot of evidence to rule out other explanations and present a compelling case. Either of these two cosmological interpretations would have important consequences. Many studies in cosmology, including X-ray studies of galaxy clusters, assume that the universe is isotropic and that the correlated velocities are negligible compared to cosmic expanses at a distance from here.
K. Migakas et al. 2020. Cosmic isotope test with a new sample of X-ray galaxy grouping through the LX-T scale ratio. A&A 636, A15; Doi: 10.1051 / 0004-6361 / 201936602
This article is based on the text provided by the National Aeronautics and Space Administration.
The new study has challenged the expansion of the universe, but remains unrestricted. As for our place in the universe, there is nothing special. Not only are the laws of physics the same, but everywhere, the universe has the same scale properties everywhere.
In all directions and in all locations, the number of galaxies, the amount of clustering, the rate of cosmic expansion, and a host of other measurable properties are nearly equal. On the largest scale, the Universe actually appears the same everywhere.
But there are many different and independent ways to test the idea that the Universe is the same in all directions: what astronomers call “isotropy.” In a new study in the April 2020 issue of Astronomy and Astrophysics, a new technique, analysis, and dataset are applied to this puzzle, and the authors claim that the rate of expansion of the Universe depends on which direction we look. Huh
This is an interesting result if true, but there are many reasons to be skeptical. Why here The quantum fluctuations that occur during inflation spread throughout the universe, and when inflation ceases, they fluctuate in density. This leads to a large-scale structure in the current universe, over time, as well as temperature fluctuations in the CMB.
The growth of the structure from the fluctuations of these seeds, and their marks on the power spectrum of the temperature difference of the Universe and CMB, can be used to determine various properties on our universe. The quantum fluctuations that occur during inflation spread throughout the universe.
There is a general theory that not only governs the universe, but provides a framework for understanding what must exist on a larger scale: the inflationary Big Bang. Two-dimensional slices of the superfluous (red) and descending (blue / black) regions of the universe … [+] We have. The lines and arrows describe the direction of the peculiar flow, which are the gravitational pressures and the bridges located in the galaxies that surround us. However, all of these speeds are inherent in the space expansion structure, so a measured / observed redshift or blueshift is a combination of space expansion and the motion of a distant object.
These local variations are certainly real. When we look at how galaxies move throughout the universe, we find that they follow Hubble’s expansion on average, especially over very long distances: where each galaxy appears the fastest is directly proportional to the galaxy it is. But each galaxy also has a peculiar speed, which is above the general expansion, which can produce additional speeds of up to a few thousand kilometers per second: 1-2% of the speed of light.
We see this everywhere, from the movements of individual galaxies in small galaxies to the fluid movements of galaxy clusters at intermediate scales for the movement of our own local cluster. But most importantly (and with the greatest precision), we see our own motion with respect to the cosmic microwave background, which must be completely isotropic to the effect of its motion through space.