This is how astronomers have found universe's missing ordinary matter

Economic Times

17-06-2025

Astronomers have used fast radio bursts (FRBs) to locate the universe's missing ordinary matter. This matter had not been detected before because it was too spread out. Using 69 FRBs, the team measured matter between galaxies. Their findings agree with predictions and may help map the universe's evolution.
An artist's conception depicts warm, thin gas in a vast region between galaxies - called the intergalactic medium, in this handout illustration image obtained by REUTERS. Blue highlights denser regions of the cosmic web, transitioning to redder light for void areas. Courtesy of Jack Madden, IllustrisTNG, Ralf Konietzka, Liam Connor/CfA/Handout via REUTERS/Illustration
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Ordinary Matter Hidden in Space
FRBs Reveal Matter in Intergalactic Medium
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Observations and Measurements
Findings
FAQs
Scientists have used fast radio bursts FRBs ) to detect normal matter that was previously missing from the universe. This matter is not dark matter but baryonic matter made of atoms.For years, scientists searched for ordinary matter that should exist in the universe. This matter is not dark matter, which does not interact with light. Instead, it is normal atomic matter, also known as baryonic matter. It was missing from observation because it was thinly spread between galaxies.This matter lies in two main places. Some of it floats in the space between galaxies. The rest surrounds galaxies in large cloud-like halos. Until now, it could not be detected directly with telescopes.Astronomers used fast radio bursts (FRBs) to locate this matter. FRBs are very short but powerful radio signals. They are produced far away in space. Some last only milliseconds but release as much energy as the sun does in decades.As these bursts travel through space, they pass through matter. That matter slows the signal. Scientists used this delay to measure how much material lies in the path. This method works even when the matter is too faint to see directly.The team used 69 FRBs with known distances from Earth. These signals came from as far as 9.1 billion light-years away. Most of these bursts were detected using a network of 110 radio telescopes at Caltech's Owens Valley Radio Observatory.Instruments in Hawaii and California helped measure how far the FRBs had traveled. Other bursts were found by Australia's ASKAP telescope network, which is good at locating FRBs.The team found that 76% of ordinary matter is in the space between galaxies. About 15% is in halos around galaxies. The rest, about 9%, is inside galaxies. These results match what earlier computer models had predicted.This discovery helps scientists understand how galaxies form and grow. Future tools like the DSA-2000 telescope may detect more FRBs and improve these measurements.FRBs are short bursts of radio waves that release large amounts of energy. They last milliseconds and come from distant parts of the universe.Scientists found most missing matter in the intergalactic medium and galaxy halos using fast radio bursts as a detection tool.