The Hidden Truth: Astronomers Uncover the Location of Missing Ordinary Matter in the Universe
Astronomers have long been puzzled by the whereabouts of the "missing" ordinary matter in the universe, accounting for only 15% of all matter despite its presence in everything from planets and stars to people and trees. However, a recent breakthrough in research has finally shed light on this elusive matter, revealing that it is hiding in the vast expanses between galaxies as gas spread out in a diffuse cosmic web.
The discovery was made by a team of researchers from the California Institute of Technology and the Center for Astrophysics, who studied fast radio bursts (FRBs) - brief, bright flashes of electromagnetic radiation that travel through space. These radio waves, emanating from 69 locations across the cosmos, are so powerful that they produce more energy than our sun emits in an entire year. By measuring how the light from these radio bursts spread and dispersed while traveling toward Earth, the astronomers were able to determine how much matter was in their path.
The results of this study revealed that about 75% of the universe's ordinary matter resides in the intergalactic medium, also known as the space between galaxies. This distribution is in line with predictions from advanced cosmological simulations but has never been observed and confirmed until now. The remaining 15% of the "missing" matter exists within galaxies in the form of stars and cold galactic gas, or in the halos of diffuse material around them.
Astronomers theorize that this distribution happens as gas is ejected from galaxies when massive stars explode in supernovas or when supermassive black holes inside galaxies expel material after consuming stars or gas. The findings will help researchers better understand how galaxies grow and will be further explored by Caltech's future deep-space radio telescope, the DSA-2000, which is planned to detect up to 10,000 fast radio bursts per year.
The study was published in the journal Nature on June 16th, and it is hoped that this discovery will shed new light on the mysteries of the universe and our place within it. The image accompanying this article shows a visualization of the cosmic web, illustrating the vast interconnectedness of galaxies and the hidden secrets of the universe that have now been uncovered through this groundbreaking research.
