China claims to unveil’s the world’s largest neutral hydrogen catalog

Chinese researchers recently unveiled an extensive and high-quality catalog of neutral hydrogen (HI) sources beyond our galaxy. Termed the FAST All Sky HI Survey (FASHI), this three-year project began in August 2020, utilizing the five-hundred-meter Aperture Spherical Radio Telescope (FAST). FAST, also colloquially known as the “China Sky Eye,” officially began operations in January 2020, nestled in the Guizhou Province of southwest China.

With a reception area equivalent to 30 standard football fields, it claims to be the world’s largest single-dish radio telescope. FAST’s high spectral and spatial resolution and broader coverage make it an ideal tool for detecting faint and weak neutral hydrogen galaxies, with more reliable and complete data quality, according to a release by . Unprecedented insights into Cosmic Mysteries.

The FASHI project covered approximately 7,600 square degrees of the sky, uncovering a staggering 41,741 HI sources within disk galaxies. This trove of data, obtained between August 2020 and June 2023, surpasses similar catalogs in both quantity and quality from around the globe. The findings were published in the journal .

, the most abundant element in the universe, plays a pivotal role in the formation and structure of galaxies. In disk galaxies, neutral hydrogen (HI) is a crucial component of the interstellar medium. The FASHI project’s measurement of HI abundance and kinematics through the 21-centimeter emission line opens doors to addressing profound questions, including dark matter’s properties, faint unknown galaxies’ existence, and the broader cosmic structure and evolution.

Global Collaboration and Future Prospects. The project’s research team, which included scientists from Guizhou University, the National Astronomical Observatories under the Chinese Academy of Sciences, and Peking University, has shared the observational data with researchers worldwide. Despite covering only 35 percent of the total sky in the current survey, the researchers anticipate recording over 100,000 neutral hydrogen sources over the next five years.

Lister Staveley-Smith, a professor from the University of Western Australia and a peer reviewer of the paper, lauded the work as “an impressive milestone. ” As FASHI progresses, it is poised to provide the largest extragalactic HI catalog, offering an unprecedented objective view of HI content and large-scale structure in the local universe. FAST was previously in the news in July, earlier this year, when astronomers discovered a quasi-periodic oscillation (QPO) signal in the radio band for the first time, shedding light on a microquasar called , using the radio telescope.

It was also part of last year’s experiment when researchers picked up techno-signatures of an intelligent alien civilization. However, these signals were deemed to be originating from human technology. In August, China announced it would soon allow and platforms to provide maintenance services for the world’s largest radio telescope.

This robotic solution would help resolve long-standing issues relating to low manual maintenance efficiency and climatic conditions restricting observation. .