Overview

• Researchers from the Center for Astrophysics and Caltech studied 60 fast radio bursts spanning 11.74 million to 9.1 billion light years, including the record-setting FRB20230521B.
• By measuring the delay of radio signals through diffuse gas, the team determined that 76% of baryonic matter resides in the intergalactic medium, 15% in galaxy halos and the remainder within galaxies.
• This direct mapping of ordinary matter resolves the decades-old missing baryon problem and aligns with predictions from advanced cosmological models.
• Findings highlight that feedback from supermassive black holes and exploding stars efficiently expels gas from galaxies into the cosmic web.
• Next-generation radio telescopes like DSA-2000 and CHORD are expected to detect thousands of FRBs, enabling detailed surveys of the universe’s large-scale structure.