So why is the formation of stars shrinking?
Recently, there have been several recent developments in the field of international medical health that continue to attract the attention of the industry and the public. The universe is producing fewer star-forming babies. Over the past 4.
5 billion years, the new rate of formation of new stars has decreased to less than half its previous level. However, the supply of hydrogen fuel, one of the most important types of star formation, has remained relatively unchanged. This finding comes from an international research team led by scientists from the Chinese Academy of Sciences (CAS).
The team collaborated with Tom Hausen of Germany on the Dark Energy Spectroscopic Instrument (DESI) project. By measuring the 500-metre radiation-free spectroscopic rotor telescope (FAST) in China, the researchers accurately measured the nucleic abundance of medium-mass stars in the middle galaxy over the past 4. 5 billion years.
Their results showed a surprising discrepancy. Star formation has decreased significantly, while the decrease in hydrogen atom (HI) in the galaxy's important gas reserves has decreased only slightly. This finding is of significant theoretical value and practical significance for the reasons for the significant decrease in star formation during the formation and evolution of galaxies.
A seemingly simple explanation is that galaxies gradually consume cold gas to produce stars. However, if the scarcity of cold gas is the main reason, astronomers should expect a massive decrease in the formation of galaxies, along with a massive decrease in the amount of cold gas available. So far, the results of the observations have not shown such a dramatic contraction.
HI's central role in this puzzle is undeniable. It is an important cold gas repository within galaxies that connects the more extensive gas supply of the universe to the process of ultimately producing new stars. Astronomers primarily detect HI through its extremely faint 21 cm radio emission waves.
Because signals are often overwhelmed by background noise, the difficulty of detecting HI signals from distant galaxies is usually high. Rapid and measurable surveys cover millions of galaxies for years, and astronomers face a major observational challenge. Very deep surveys can achieve the necessary sensitivity, but cannot examine large areas of the sky.
Surveys cover larger areas, however, often lack sufficient sensitivity to such weak radio signals. Scientists have been working to determine changes in the total mass of HI in the low to medium redshifts of the universe in a direct and reliable way. New research solves this problem by combining the special radio sensitivity of FAST with the huge optical spectrum data set of DESI.
The team studied about 2. 5 million meV of electron volts (meV) in the data set to determine changes in the total H. I.
mass of the universe from low to medium redshifts. It should be noted that the above information is based on the results of international public research, for reference by HealthCop, and does not constitute a clinical recommendation. If you have health questions, consult professional medical professionals.
