China’s FAST Puts Together Largest Atlas Of Universe’s Gas Bodies
China’s Five-hundred-metre Aperture Spherical Radio Telescope (FAST) has detected 156,411 neutral hydrogen sources across nearly half of the entire sky, creating the world's largest atlas of such cosmic gas bodies, according to the Global Times.
The number of detected sources surged from around 40,000 to 156,411 following two years of observations, while their sky coverage expanded from 7,600 square degrees to 19,500 square degrees, nearly half of the entire sky.
Neutral hydrogen is the oldest and most fundamental form of matter in the universe, serving as the "raw material" for stars and the "building blocks" of galaxies. Its 21-centimetre radiation can penetrate interstellar dust, carrying information about the universe's primordial gas to Earth.
The latest dataset, dubbed FASHI DR2 and published in Science China Physics, Mechanics & Astronomy, increased the number of detected sources to five times the previous record set by the ALFALFA survey conducted with the US Arecibo Telescope.
The data are expected to advance research into galaxy formation and evolution, dark matter distribution, large-scale cosmic structures, and gravitational-wave sources. Researchers also determined the local neutral hydrogen density with a statistical precision of 0.6 percent, the most accurate measurement to date.
Located in southwest China's Guizhou Province, FAST is the world's largest single-dish radio telescope and has a reception area equivalent to 30 standard football fields.