# A gas rich cosmic web revealed by partitioning the missing baryons

**Authors:** Liam Connor, Vikram Ravi, Kritti Sharma, Stella Koch Ocker, Jakob Faber, Gregg Hallinan, Charlie Harnach, Greg Hellbourg, Rick Hobbs, David Hodge, Mark Hodges, Nikita Kosogorov, James Lamb, Casey Law, Paul Rasmussen, Myles Sherman, Jean Somalwar, Sander Weinreb, David Woody  
**arXiv:** [2409.16952](https://arxiv.org/abs/2409.16952)  
**Date:** 2024-09-25  
**Summary page:** https://www.summarizepaper.com/en/paper/2409.16952v1/

## Key points

- Groundbreaking study on distribution of baryonic matter in the Universe
- Partitioning missing baryons into intergalactic medium (IGM), galaxy clusters, and individual galaxies
- Late-Universe measurement of total baryon density: $\Omega_b h_{70}$=0.049$\pm$0.003
- Insights into feedback processes within galaxies and gas expulsion mechanisms
- Alignment with enriched cosmic web scenarios from cosmological simulations
- Challenge to existing models predicting high total stellar density ($\Omega_*$)
- Emphasis on understanding distribution and dynamics of baryonic matter for galaxy formation and evolution
- Refinement of understanding of cosmic baryon content and astrophysical feedback processes
- Implications for observational cosmology and further exploration into Universe's structure and evolution

## Summary

Researchers have conducted a groundbreaking study on the distribution of baryonic matter in the Universe, shedding light on the elusive cosmic web that connects galaxies and clusters. By analyzing a vast cosmological sample of Fast Radio Burst (FRB) sources localized to their host galaxies, the team has successfully partitioned the missing baryons into distinct regions - the intergalactic medium (IGM), galaxy clusters, and individual galaxies. This meticulous approach has led to a late-Universe measurement of the total baryon density, revealing a value of $\Omega_b h_{70}$=0.049$\pm$0.003. The results provide crucial insights into feedback processes within galaxies and showcase how efficient mechanisms can expel gas from galaxy halos into the intergalactic medium. This finding aligns with enriched cosmic web scenarios observed in state-of-the-art cosmological simulations, highlighting the dynamic interplay between galactic structures and their surrounding environment. Moreover, by accurately quantifying the diffuse baryon fraction present in different cosmic regions, this research challenges existing models that predict a high total stellar density ($\Omega_*$). The data disfavors bottom-heavy stellar initial mass functions, emphasizing the significance of understanding the distribution and dynamics of baryonic matter for advancing our knowledge of galaxy formation and evolution. Overall, this comprehensive analysis not only refines our understanding of cosmic baryon content but also underscores the intricate nature of astrophysical feedback processes and their implications for observational cosmology. The findings pave the way for further exploration into the complex interactions shaping our Universe's structure and evolution.