The cosmic web is the vast, large-scale structure of the universe, where matter is organized into a network of filaments, sheets, and voids rather than being distributed uniformly. Galaxies, galaxy clusters, and dark matter are concentrated along dense filaments, while immense cosmic voids—regions with very few galaxies—separate these structures.
Key features of the cosmic web include:
- Filaments: Long, thread-like structures connecting clusters and groups of galaxies, containing both dark matter and intergalactic gas.
- Voids: Vast empty regions, often tens to hundreds of millions of light-years across, with very low galaxy density.
- Nodes and Clusters: Points where filaments intersect, hosting galaxy clusters and massive structures.
The cosmic web arises from gravitational collapse of matter in the early universe, guided by dark matter and amplified from small density fluctuations observed in the cosmic microwave background (CMB). Studying it allows astronomers to:
- Understand the distribution of matter on the largest scales.
- Trace the evolution of galaxies and clusters within the cosmic framework.
- Investigate the role of dark matter and intergalactic gas in structure formation.
In essence, the cosmic web is the skeleton of the universe, illustrating how galaxies and matter are interconnected across billions of light-years and revealing the underlying architecture shaped by dark matter and cosmic evolution.