Chinese and foreign scientists jointly released a huge two-dimensional map of the universe: 10 trillion pixels contains 2 billion celestial bodies

It is learned from the National Astronomical Science Data Center that on January 14, Beijing time, the Beijing-Arizona Sky Survey (BASS) team of the National Astronomical Observatory and the Dark Energy Spectroscopic Sky Survey (DESI) international cooperation project team jointly released the latest huge two-dimensional sky map of the universe. The beginning of a new generation of cosmological redshift surveys paved the way.

" This is the largest cosmic sky map that we have measured so far. The sky map covers an area of ​​20,000 square degrees, about half the area of ​​the celestial sphere, contains 10 trillion digital pixels, and contains 2 billion celestial bodies ." David Schlegel, a project scientist from LBNL and DESI, said.

According to reports, modern astronomical observation studies have found that the universe is constantly expanding and in a state of accelerated expansion. The force that drives the expansion of the universe is called dark energy by astronomers.

Dark energy is still a mystery to this day. It accounts for about 68% of the universe. The remaining matter is dark matter and ordinary baryon matter. By observing the spectrum of a large number of galaxies in the universe, people can accurately obtain the retrograde speed of the galaxy, that is, the redshift, and thus the distance of the celestial body.

The redshift measurement of large-scale galaxies can accurately depict the three-dimensional distribution of cosmic matter and accurately outline the influence of dark energy on the expansion of the universe.

DESI Sky Survey is a new-generation cosmological redshift survey project that studies the growth and expansion history of the universe's structure through redshift observations of a large number of galaxies.

The project is an international cooperation project supported by the U.S. Department of Energy and the U.S. Nature Foundation. The lead unit is the Lawrence-Berkeley National Laboratory (LBNL), a unit of the U.S. Department of Energy. The participating countries include China, France, Spain, the United Kingdom, Australia, and Canada. , Mexico, Switzerland, South Korea, and Colombia.

Zhao Gongbo, a member of the DESI project and deputy director of the National Astronomical Observatory, mentioned: “ DESI is known as the fourth-generation cosmological survey project after the Sloan Spectral Survey. It plans to use 5 years to obtain the redshifts of tens of millions of galaxies. Constructing the largest three-dimensional universe at present is expected to reveal the mystery of dark energy."

Nathalie Palanque-Delabrouille, a cosmologist at the French Atomic and Alternative Energy Commission and DESI spokesperson, commented: “We have made significant achievements in collecting and processing these data. Without these data, the DESI sky survey project cannot be carried out.”