This ionized hydrogen gas is a significant component of the universe's normal matter, which accounts for 15% of total matter, while dark matter constitutes the remaining 84%.

Astronomers have recently identified that more than half of the universe's normal matter, specifically ionized hydrogen gas, has been missing but is now found in extensive haloes surrounding galaxies.

The discovery indicates that this gas does not distribute uniformly around galaxies; instead, it follows cosmic filaments that connect them.

The study indicates that massive black holes at the centers of galaxies are more active than previously thought, ejecting gas up to five times farther than expected.

Understanding the distribution of this ionized hydrogen gas is crucial for addressing cosmological problems and refining models of galaxy formation and evolution.

The techniques employed in this research could also enhance our ability to probe the early universe and test fundamental physics, including gravity and general relativity.

These findings help resolve discrepancies between astronomical observations and the established model of the universe's evolution since the Big Bang 13.6 billion years ago.

The research, led by Boryana Hadzhiyska from UC Berkeley, utilized images of approximately 7 million galaxies and measured changes in the cosmic microwave background to detect this elusive gas.

The analysis was bolstered by data from the Dark Energy Spectroscopic Instrument and the Atacama Cosmology Telescope, which provided the most accurate cosmic microwave background measurements prior to its decommissioning in 2022.

This finding suggests that black holes may expel gas not only during their formative years but also at various points throughout their lifespan, challenging existing theories regarding active galactic nuclei.