Первый слайд презентации: Astronomers Use Slime Mould to Map the Universe’s Largest Structures
Naumushkin Ilya 2nd year AM – 28 Teacher : A.V. Yurieva
Слайд 2: The behaviour of one of nature’s humblest creatures and archival data from the NASA/ESA Hubble Space Telescope are helping astronomers probe the largest structures in the Universe
The single-cell organism known as slime mould builds complex web-like filamentary networks in search of food, always finding near-optimal pathways to connect different locations. The cosmic web is the large-scale backbone of the cosmos, consisting primarily of dark matter and laced with gas, upon which galaxies are built. The Cosmic Web (Artist’s Impression )
The existence of a web-like structure to the Universe was first hinted at in galaxy surveys in the 1980s. Now a team of researchers has turned to slime mould to help them build a map of the filaments in the local Universe (within 100 million light-years of Earth) and find the gas within them. They designed a computer algorithm, inspired by the behaviour of slime mould, and tested it against a computer simulation of the growth of dark matter filaments in the Universe. The Cosmic Web Slime mould
The researchers then applied the slime mould algorithm to data containing the locations of over 37000 galaxies mapped by the Sloan Digital Sky Survey. The algorithm produced a three-dimensional map of the underlying cosmic web structure. They then analysed the light from 350 faraway quasars catalogued in the Hubble Spectroscopic Legacy Archive. Imprinted on that light was the telltale signature of otherwise invisible hydrogen gas that the team analysed at specific points along the filaments. These target locations are far from the galaxies, which allowed the research team to link the gas to the Universe’s large-scale structure.
“It’s really fantastic that one of the simplest forms of life actually enables insights into the very largest-scale structures in the Universe,” said lead researcher Joseph Burchett of the University of California (UC), U.S.A. “ By using the slime mould simulation to find the location of the cosmic web filaments, including those far from galaxies, we could then use the Hubble Space Telescope’s archival data to detect and determine the density of the cool gas on the very outskirts of those invisible filaments. Scientists have detected signatures of this gas for over half a century, and we have now proven the theoretical expectation that this gas comprises the cosmic web.” UC Santa Cruz
The survey further validates research that indicates intergalactic gas is organized into filaments and also reveals how far away gas is detected from the galaxies. Team members were surprised to find gas associated with the cosmic web filaments more than 10 million light-years away from the galaxies. But that wasn’t the only surprise. They also discovered that the ultraviolet signature of the gas gets stronger in the filaments’ denser regions, but then disappears. “We think this discovery is telling us about the violent interactions that galaxies have in dense pockets of the intergalactic medium, where the gas becomes too hot to detect,” Burchett said.
Последний слайд презентации: Astronomers Use Slime Mould to Map the Universe’s Largest Structures: Map of the Cosmic Web Generated from Slime Mould Algorithm
The researchers turned to slime mould simulations when they were searching for a way to visualise the theorised connection between the cosmic web structure and the cool gas, detected in previous Hubble spectroscopic studies. The research team was inspired by how the slime mould builds complex filaments to capture new food, and how this mapping could be applied to how gravity shapes the Universe, as the cosmic web constructs the strands between galaxies and galaxy clusters.