MUSER, Inner Mongolia （Photo/Xinhua）

According to the latest cosmological study released on July 20 by the extended Baryon Oscillation Spectroscopic Survey (eBOSS) collaboration, professors Zhao Gongbo and Wang Yuting from the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) detected the existence of dark energy at a significance of 11 s. This is the strongest evidence yet of dark energy from galaxy surveys.

Based on the observations and statistics from eBOSS, researchers have proposed new theories and developed new methods for data analysis. Through the cross-correlation of two types of galaxies, they have successfully measured the history of cosmic expansion and structure growth within a distance range of 0.7-1.8 billion light years away — an area which research had not previously examined.

"The results of the measurement prove the existence of dark energy, and the observations from eBOSS are consistent with our previous findings on the dynamics of dark energy,” explained Zhao.

Data analysis, especially regarding observational errors and systematic bias, remains one of the major challenges for the cosmological study of galaxies. As the world's first multi-target galaxy survey conducted in a vast cosmic volume, eBOSS makes it possible to conduct cross-correlation analysis.

"In addition to reducing statistical error, cross-correlation can also effectively minimize systematic bias, so as to get more accurate and reliable results," said Wang.

Dark energy is the dominant component of the current universe, which is why revealing its nature is of such scientific significance. The eBOSS collaboration is composed of over 30 world-class astronomical institutions, including the NAOC. Over the past six years since it began operations in 2014, eBOSS has taken almost 1 million galaxy spectra in the redshift range of 0.6<z<2.2. In addition, it has made a series of key scientific achievements and successfully completed its missions.

Zhao, who is also director of a science working group for the eBOSS collaboration, has been participating in and leading cutting-edge applied research in the field of cosmology under the project, such as galaxy surveys, data processing and dark energy.

This latest research has laid a solid foundation for studying the nature of dark energy via galaxy surveys on a larger scale, such as using the Chinese Space Station Telescope, Dark Energy Spectroscopic Instrument (DESI), and Prime Focus Spectrograph (PFS).

You can also read this article at: http://www.china.org.cn/china/2020-07/23/content_76305349.htm