The dark energy Spectroscopy Tool (DESI) has completed its first seven months of exploration by breaking all previous records for three-dimensional galaxy studies and is the largest and most accurate Has created the map of the universe.
But this is only about 10% of the path of the five-year mission of this amazing scientific tool. Once completed, this highly detailed three-dimensional map gives physicists and astronomers a better understanding of dark energy and, consequently, the past and future of the universe. However, the impressive technical performance and achievements of this cosmic mapping are still helping scientists unravel the mysteries of the world's most powerful light sources.
Called DESI, it is an international partnership run by the US Department of Energy's Berkeley Lab National Laboratory (DOE) and funded by the DOE Office of Science and Technology.
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" "There are many beauties in these results. In the distribution of galaxies in a three-dimensional map, huge clusters, strings, and holes are seen. These are the largest structures in the universe. But on the other hand, inside them you will find traces of a very primitive world and a history of expansion since then.
Desi has come a long way to reach this point. This scientific tool for exploring dark energy, at first more than a decade ago, was proposed and finally its construction began in 2015 (solar 2015). The instrument is mounted on a 4-meter Nicholas Mial Telescope at the Kitt Peak National Observatory. The Keith Peak National Observatory near Tucson, Arizona Science (NSF) is a US company contracted by the US Department of energy to operate desi instruments on the Mial Telescope. The device made its first light exposure in late 2019, but then, during the validation phase, the Corona virus outbreak shut it down for several months; However, some activities continued remotely. In December 2020, Desi turned his eyes to the sky again and tested his hardware and software. This scientific tool was finally prepared in May 2021 (May 1400) and began its scientific studies.
three-dimensional CT scan of the universe; The Earth is
on the lower left, and this data covers more than 5 billion
light-years in the constellation Virgo. Each color dot in this
image is a galaxy made up of hundreds of billions of stars.
Credit: D. Schlegel/Berkeley Lab using data from DESI
But work on its development The Desi tool did not end with the beginning of the mapping of the universe. "Continuous work is ongoing for the instrument to work properly," said Klaus Honscheid, a physicist at Ohio State University and a scientist at the project.
He and his team make sure that the instrument Works properly and automatically and ideally without the need for any input during an observation night. According to Hunsheid, according to the feedback he receives from staff and night owls, these shifts are usually tedious, but this is good news for the team because it shows that the tool works perfectly automatically.
This productivity is monotonous but necessary. Precise control over each of the 5,000 advanced robots that secure the optical fibers on the decis device and ensure that their position is adjusted to an accuracy of up to 10 microns. "Ten microns is very small and less than the thickness of a human hair," he added. You have to position each robot to collect the light of galaxies billions of light-years away. Every time I think of this system, I wonder how we can move it forward. Desi's success as a tool is something to be proud of.
Seeing the true face of dark energy
Of the millions of galaxies in more than a third of the total sky is essential. By decomposing each galaxy's light into its constituent color spectrum, Desi can determine how much light has shifted toward the red spectrum. As the universe expands over billions of years, galaxy light travels to the red end of the electromagnetic spectrum before reaching Earth, a redshift that allows Desi to see the depths of the sky.
In general, The more the spectrum of the galaxy shifts to red, the farther away it is. With a three-dimensional map of the universe, physicists can map and classify galaxy clusters and superclusters. These structures have an echo of their early formation, when they were just waves in the infant world. By examining these echoes, physicists can use DESI data to determine the history of the universe's expansion. "Our scientific goal is to measure the effect of these waves on early plasma," Guy said. "It's amazing that we can really detect the impact of these waves on our mapping billions of years later." Understanding the history of the universe's expansion is crucial, and nothing less than the unknown fate of the entire universe. Today, about 70% of the universe's content is dark energy, a mysterious form of energy that speeds up the universe's expansion. Gives and with this cycle, the share of dark energy in the universe always increases. Ultimately, dark energy determines the fate of the world: Will the world expand forever? Will it collapse again in an inverted Big Bang? Or does it have a Big Rip?
Answering these questions requires learning more about how dark energy behaves in the past, and this is exactly what Desi was designed to do, and scientists by comparison The history of the expansion of the universe, and its history of growth, can examine whether Einstein's theory of general relativity applies to these vast expanses of space-time. The fate of the universe still needs more mapping by Desi. A tool that advances our understanding of the distant past, more than 10 billion years ago, when galaxies were still young. "It's amazing," the project said. "Desi will tell us more about the physics of the formation and evolution of galaxies than ever before."
Bucha et al. Huge black holes are thought to exist in the nuclei of almost every large galaxy, such as the Milky Way. But whether small galaxies always have (smaller) black holes at their center is still unclear.
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It is almost impossible to find black holes on their own. But if these objects absorb enough material, they will be easier to detect. An active Galactic Nucleus (AGN) forms when gas, dust, and other matter that falls into a black hole (up to temperatures hotter than a star's core) heat up in its path.
Active galactic nuclei in large galaxies are among the brightest known objects in the universe. But in smaller galaxies, AGN objects can be much brighter and therefore more difficult to distinguish from newborn stars.
The new quasar discovered by Desi gives an overview of
the universe 13 billion years ago. This is the farthest quasar ever
discovered by Desi.
Credit: Jinyi Yang, Steward Observatory/University of Arizona
Spectra recorded by the DESI dark energy exploration tool could help solve this problem Its slow and wide range of exploration across the sky provides more information about the active nuclei of small galaxies than ever before. These nuclei, in turn, provide scientists with clues as to how bright AGN objects formed in the early universe. Quasars are special types of galaxies and the brightest and farthest known objects in the universe. "I like to think of them as light bulbs that take us back in time into the history of the universe," said Victoria Fawcett, an astronomy graduate from Durham University in the United Kingdom. Quasars, because of their pure power, are the great explorers of the early universe and help decis data go back 11 billion years.
He and his colleagues use decis data to understand the evolution of quasars themselves. Quasars are thought to be covered with a layer of dust, which reddens the light emitted from them (to the red spectrum); Like sunlight passing through the fog. Then, with age, the dust disappears and the quasar becomes bluer.
But because there is little data on red quasars, it has been difficult to test this theory. The Desi dark energy Exploration Tool is now changing this trend, finding more quasars than any previous search, and is estimated to identify 2.4 million quasars in the final data.
Fast said: "Desi is really great because it also records much brighter, redder objects. "It allows scientists to test ideas that were not previously possible about the evolution of quasars."
And this exploration is not limited to quasars. "We are finding many strange systems, including large specimens of rare cosmic objects that we have not been able to study in detail before," Faust said. The search has so far indexed more than 7.5 million galaxies, adding to the number of galaxies listed at a rate of more than one million per month. In November 2021 alone, the redshift tool indexed 2.5 million galaxies. Enable a great deal of cosmological and astrophysical research. "All this data is there and they are just waiting to be analyzed," Pucha said. "Based on this data, we will find some very interesting things about galaxies." American National Science Foundation, British Science and Technology Institutional Council, Gordon and Betty Moore Foundation, Heising-Simons Foundation, French Commission on Alternative energy and Atomic energy (CEA) , The Mexican National Council of Science and Technology and the Spanish Ministry of Economy are other sponsors of this scientific tool. : D. Schlegel/Berkeley Lab using data from DESI
Source: SciTechDailyTags: universe's, largest, three-dimensional, map, revealed, new, details, dark, energy