The latest research found that the ultraviolet light emitted by known galaxy clusters and quasars is far from enough to produce the observed amount of hydrogen between galaxies, which is four times less. “It’s like you come to a big room with bright lights, but you look around and see only a few 40 watt bulbs. Where does the light come from? We can’t find its source. “
That’s the question of comer of the Carnegie Institute of science, the lead author of the study. The team analyzed the distribution of hydrogen ions that bridge the gap between galaxies. When a hydrogen atom is hit by high-energy ultraviolet light, it will change from an electrically neutral hydrogen atom to a charged hydrogen ion. The photons that can change neutral hydrogen into hydrogen ions are called “ionized photons”, which mainly come from quasars and the hottest young stars. Therefore, intergalactic hydrogen ions can be used as accurate “spectrometers”.
Astronomers were surprised when they found that there were too many hydrogen ions, because it exceeded the amount of hydrogen ions that ultraviolet rays could produce, and the difference was a staggering 400%. Strangely enough, this mismatch only occurs in the nearby universe that humans know better.
Scientists aim their telescopes at galaxies billions of light-years away. What they see is the situation of the universe when it was young. They find that the amount of ultraviolet light in the early universe met the amount needed to ionize hydrogen atoms. However, scientists are puzzled why the difference is so large in the near future.
The researchers analyzed the data from the Hubble Space Telescope cosmic origin spectrometer, and compared the results with the amount of hydrogen ions between galaxies simulated by the supercomputer to find the difference.
The observation shows that almost all the ionized photons emitted by young stars are absorbed by the gas of their host galaxy, and it is almost impossible to escape to affect the hydrogen between galaxies. The number of known quasars is far from enough to produce enough ultraviolet light to produce the amount of hydrogen ions observed.
“The model fits perfectly with the data from the early universe, and if we can assume that the extra light really exists, it fits perfectly with the nearby universe,” said Oppenheimer of the University of Colorado, co-author of the paper. “It’s also possible that the model doesn’t reflect the real situation. If so, it’s also surprising to us, because intergalactic hydrogen is what we think we know best about the universe.”
“We calculated ultraviolet ionized photons from known sources and found that they were four times less,” Oppenheimer said. “Where do 80% of the ionized photons come from? It is likely that there are new sources, not quasars or galaxies where photons escape.
The mysterious dark matter that binds galaxies together may be related to mysterious light, such as the decay and luminescence of dark matter. “If you think about dark matter decay seriously, it’s a crisis,” said coauthor Katz of the University of Massachusetts
Daily smile: yesterday, my aunt in the same community introduced me to my partner and said, “my daughter is studying in Japan. She has found a job recently. This is a new mobile phone she bought for me. This is her photo. Look, isn’t it beautiful?” I looked at it and asked, “Auntie, how familiar is this one? Is there a mole on her thigh?