By analyzing initial data from the DESI spectrometer, an international team of astronomers identified 95 new galaxies with extremely low metal abundances and low redshifts. This discovery is detailed in his December 1st article on the preprint server arXiv. Extremely metal-poor galaxies (XMPGs) are galaxies with metallicity less than 0.1. Because these galaxies are chemically underdeveloped, they serve as excellent laboratories for exploring theories of the chemical evolution of galaxies and for studying physical processes during the early stages of evolution. A team of astronomers led by Hu Zou of the University of the Chinese Academy of Sciences in Beijing, China, has obtained a large XMPG sample based on early DESI data. The researchers first selected 1,623 star-forming galaxies with prominent oxygen emission lines. In this sample, we identified 223 galaxies with redshifts less than 1.0 and extremely low metal abundances.
Scientists confirmed that 95 of them are true XMPGs, but 128 galaxies remain XMPG candidates. Most of his XMPGs reported in this study were found at low redshifts below 0.3 and turned out to be dwarf galaxies with stellar masses less than 1 billion solar masses. The galaxy with the least metal in the sample was named DESIJ150535.89+314639.4. The star’s oxygen content is only 1/34th that of the Sun, the star’s mass is approximately 15 million solar masses, and its star formation rate is estimated to be 0.22 solar masses per year. Astronomers noted that preliminary examination of images of two metal-poor galaxies found in the sample revealed two distinct morphologies. This suggests a different evolutionary and physical origin. However, further research is required to confirm this hypothesis.