2023-12-13 08:34:00
BEIJING, Dec. 13 (Xinhua) — Using the Five Hundred Meter Aperture Spherical Radio Telescope (FAST), or “China’s Eye of the Sky”, a team of Chinese astronomers has compiled the largest catalog of high quality sources of neutral hydrogen (HI) beyond our galaxy.
Hydrogen, the most abundant element in the universe, is a key component of galaxies. In disk galaxies, neutral hydrogen is an important component of the interstellar medium.
Measuring its abundance and its kinematics by the 21-centimeter emission line could make it possible to address a number of astrophysical questions, such as the possible properties of dark matter, unknown faint galaxies, as well as the structure and the evolution of the cosmos.
The new catalog contains a total of 41,741 HI sources discovered between August 2020 and June 2023, surpassing in quantity and quality similar catalogs existing around the world.
This work is part of a project called FAST All Sky HI survey (FASHI), designed to cover the entire sky visible to FAST. The results of the current study come from approximately 35% of the total sky, and more than 100,000 HI sources are expected to be recorded over the next five years.
FAST is the world’s largest single-disk radio telescope, with a reception area equivalent to 30 standard football fields. FAST officially started operation on January 11, 2020, in a naturally deep and round karst depression in Guizhou Province, southwest China.
FAST is an optimal tool for HI studies, with higher spectral and spatial resolution, wider coverage, and more reliable and comprehensive data quality.
Once completed, FASHI will provide the largest extragalactic catalog of HI as well as an objective view of HI content and large-scale structure in the local universe.
The results were recently published in the journal “Science China: Physics, Mechanics and Astronomy”. Researchers from Guizhou University, the National Astronomical Observatories of the Chinese Academy of Sciences and Beijing University all contributed to the study. END
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