[The Epoch Times, October 30, 2022](The Epoch Times reporter Li Wanhong compiled and reported) Scientists have seen huge, never-before-seen structures in space that stretch nearly a billion light-years across, according to a new study. Emits a faint radio glow. The new discovery by the research team may provide new clues to some of the key unsolved mysteries in the universe.
The “megahalos” observed by the study consist of high-energy particles. But what energizes it, and how they appear in galaxy clusters, remains unclear. Finding the answers to these questions will not only uncover the source of the giant halo, but also explain some fundamental and unsolved puzzles in the universe, including the massive web of matter and gas that connects the universe— — Details of the cosmic web.
By the University of Hamburg astrophysicist Virginia. A research team led by Virginia Cuciti discovered four giant halos while scanning hundreds of distant galaxy clusters with the Low-Frequency Array Telescope. Low-frequency arrays are radio telescope observatories scattered across Europe that are quite sensitive to low-frequency radio.
The four giant halos are associated with some smaller radio halos. These small radio halos are scattered structures of electrons traveling near the speed of light (also known as relativistic electrons) and have been observed in many galaxy clusters. The size of the giant halo is 30 times larger than the previously observed small halo, yet its brightness is 20 times dimmer.
According to the paper published in the journal “Nature” on September 28, the researchers said that the existence of the huge halo shows that outside the wireless halo, guided by the magnetic field, its operation mechanism also maintains a large number of relativistic electrons. The researchers also added that “the mechanism of operation of this large-scale radio transmission is still unknown.”
Explore galaxy clusters in depth
“When we were analyzing one set of data from the galaxy clusters in this study, we found some important clues about very large-scale radio emissions. So we decided to re-examine all the images from the sample of 310 galaxy clusters. Our goal was to To find similar launches,” Cusiti continued. “When we found that three other galaxy clusters in the sample showed radio emission with similar scale and characteristics to the target, then it became clear that we had indeed discovered a new type of cosmic phenomenon that opened up the use of radio observations to explore galaxies. Possibilities in areas outside the regiment.”
Galaxy clusters can hold hundreds or thousands of galaxies, and the gravitational interactions among them make them some of the brightest and most chaotic environments in the universe. Even from billions of light-years away, we can often clearly see the brightest parts of galaxy clusters through telescopes on Earth. However, we know very little about the darker spaces between galaxies “inside the cluster”.
Scientists have previously observed radio halos at the centers of many galaxy clusters, especially those that are merging together. This means that electrons gain energy from galactic mergers, and then, under the influence of strong magnetic fields, form swollen halo structures. The newly discovered giant halos have rather unique properties, pointing to a different energy supply mechanism, perhaps related to the turbulence caused by the dissipation of gravitational energy in the medium of the galaxy cluster.
“There’s a lot more to learn about the giant halo,” Cusiti said. “We need more sensitive radio observations to see the properties of these exotic radio sources and to understand whether giant halos are only present in certain galaxy clusters, or are present in most galaxy clusters. Low frequency The array is currently being upgraded to Low Frequency Array 2.0, and we are very confident that its increased sensitivity will help us find answers to these questions.”
“Through these observations, we now have some measurable data about the outer regions of the cluster,” she continued. “Because it appears frequently in astrophysics, we will include computer simulations in the study. We plan to conduct a coverage An extensive computer simulation project of cosmology aimed at replicating the existence and properties of giant halos.”
Helps to learn more about the cosmic web
The cosmic web is a “sophisticated filamentary structure” that spans the universe, and through these efforts, the research team will eventually come to new insights into the cosmic web. Clusters of galaxies are made of gas and mysterious dark matter, and appear where these filaments intersect. Matter in the darker outer regions, which flow between the filaments, gradually accumulates into galaxy clusters, but this dark region remains difficult to investigate. Giant halos now offer a new way to explore the dark, elusive fringes of galaxy clusters.
“The fact that we can investigate these regions through the giant halos means that we can see how energy is dissipated during the formation of large-scale cosmic structures and how particles are accelerated when plasma density is extremely low.” Siti said. “Furthermore, the giant halo is also a very important step towards direct detection of the large-scale structure of the universe.”
“The existence of ultra-dense filaments, walls, and clumps of matter in the universe can usually be inferred from observations of galaxies in these regions, but now we are beginning to understand the plasma to observe,” she added. “The ultimate goal is to understand the unique states of matter in the ultra-dense regions of the universe, and to trace its structure and deduce their evolutionary patterns.”
The golden age of radio astronomy
The Low Frequency Array Telescope is part of a new generation of ultrasensitive radio arrays. It will revolutionize our understanding of the universe by revealing extrasolar objects, surveying the vast cosmic web, and many other discoveries. Scientists are also very much looking forward to the completion of the Square Kilometer Array (SKA), which will be the most sensitive radio telescope ever built and put into operation within the next decade.
“This will be the golden age of radio astronomy.” The radio wavelengths that can be observed on Earth range from a few meters to tens of meters. “The low-frequency array opens up a whole new window of observation, covering the lowest radio frequencies we can observe from Earth,” said Cusiti. One of the discoveries.”
“On the other hand, the unprecedented transnational cooperation on the square kilometer array will bring about the most sensitive and precise radio interferometer (a series of cooperative radio telescopes) ever built by mankind.” She mentioned To, “In addition, these devices will cover a variety of key topics in modern astrophysics. For example, the study of the primordial universe, the formation of the first stars and black holes, and the still mysterious dark energy. , and the understanding of the origin of magnetic fields in space.”◇#
Responsible editor: Sun Yun