China Tianyan’s major discovery, the first detection of neutral hydrogen, or cracking the mystery of the mysterious dark matter
China Skyeye is the world’s largest single-disc spherical radio telescope. After it was built, commissioned and started to operate, its extraordinary sensitivity Is playing an important role in cosmic radio detection. Recently, an international team of scientists used the observation time of Sky Eye to discover neutral hydrogen atoms in three galaxies outside the Milky Way for the first time, which is expected to make important contributions to cracking the mystery of dark matter.
This research comes from the collaboration of the South American Astronomy Center of the Chinese Academy of Sciences and the University of Valparaiso in Chile. The researchers used the Chinese celestial eye to conduct a pilot observation of a group of low-redshift star-forming galaxies and successfully detected from 4 galaxies. To the neutral hydrogen emission lines of the three galaxies, and the exposure time took only 5 minutes, the extraordinary sensitivity of the Chinese sky eye left scientists with a very deep impression, and it may become a new important weapon for exploring the universe in the future.
Neutral hydrogen is the primary gas widely distributed in galaxies, It is composed of baryon material in galaxies; the carbon monoxide radiation spectrum in galaxies mainly comes from the center of the galaxy. Scientists can estimate the mass of galaxies at different radii through the spectral velocity and flow distribution of these two substances:neutral hydrogen and carbon monoxide. In order to study the distribution of matter and dark matter in the galaxy.
This time, the dynamic mass of the galaxy detected by China Unicorn through neutral hydrogen is one order of magnitude higher than that of the observed baryon. The mass of the galaxy previously obtained through carbon monoxide is very similar to the mass of baryon, so scientists We estimate that using these data can better study the distribution of dark matter in galaxies.
Dark matter is the most mysterious matter in the universe, occupying the whole With 85%of the mass of the universe, once we have mastered all kinds of knowledge about dark matter, many problems in astronomy will be solved, and our understanding of the universe will enter a whole new level. However, dark matter does not interact with any matter we have seen other than gravity, so far scientists have not been able to directly detect its existence. The detection of China Sky Eye shows its importance for dark matter research, and scientists are applying for more observation time to further strengthen the study of neutral hydrogen.
This research was published on June 29 in the journal Astronomy and Astrophysics Express.