Chinese researchers have announced the sharing of neutral hydrogen samples from the largest galaxy ever discovered, along with observational data regarding the distribution of neutral hydrogen and the large-scale structure of nearby galaxies with researchers in the field of galaxy and cosmology worldwide.
This aerial panoramic photo, taken on July 26, 2023, shows China’s Five-hundred-meter Aperture Spherical Telescope (FAST) located in Guizhou Province, southwestern China. (Photo: Xinhua)
Recently, a research team from the Guizhou Radio Astronomy Observatory (Guizhou University), the National Astronomical Observatory (Chinese Academy of Sciences), and Peking University utilized survey data from the Chinese Five-hundred-meter Aperture Spherical Telescope (FAST) to construct and publish the largest neutral hydrogen sample in the world.
The team, which conducted neutral hydrogen surveys using FAST, completed a survey covering approximately 7,600 square degrees over three years and discovered 41,741 neutral hydrogen galaxy samples. The quantity and quality of this data far surpass those of other neutral hydrogen survey projects both domestically and internationally. It is expected that over 100,000 neutral hydrogen galaxies will be identified in the next five years.
Hydrogen – the first element in the periodic table – is the most abundant element in the universe and a crucial component of galaxies. Neutral hydrogen (hydrogen atoms in their ground state) is widely found in various evolutionary stages of galaxies. FAST is a powerful tool for detecting faint neutral hydrogen. Compared to previous neutral hydrogen surveys, FAST offers higher spatial and spectral resolution, broader coverage, and more reliable and comprehensive data quality.
According to researchers, the survey data is significant for studying the quantity and quality of low-quality neutral hydrogen in galaxies, constraining the properties of dark matter, discovering unknown faint galaxies, and investigating the large-scale structure and evolution of the universe.
Since the beginning of this year, FAST has achieved several important milestones, such as the first observation of the “life” of black holes in the radio wave spectrum, providing crucial evidence for the existence of gravitational waves, and discovering the shortest orbital period pulsar binary system known to date. These accomplishments continually expand the observational limits of humanity’s understanding of the universe.
FAST is a key scientific and technological infrastructure project invested in by the Chinese government, located in the autonomous region of Qiannan, Guizhou Province, in southwestern China. Construction began in 2011, and it officially became operational in early 2020. This radio telescope is the largest (equivalent in size to 30 football fields) and most sensitive in the world, serving research on the universe and the search for extraterrestrial life.
