The Digital Press

The intergalactic medium (IGM) contains most of the Universe’s baryonic matter and serves as a key cosmic reservoir and probe for understanding galaxy formation and large-scale structure. This overview highlights the IGM’s physical properties, its evolution over time, and methods used to study it through quasar absorption lines.

Why it matters: The IGM holds over 90% of baryons, crucial for tracing cosmic structure and galaxy evolution.

The big picture: Modeling IGM density, temperature, and ionization reveals how cosmic environment shapes its properties over time.

Quick takeaway: Quasar spectroscopy, especially HI absorption lines, is essential to probe the IGM’s composition and state.

Future outlook: Emerging observational techniques promise deeper insights into the IGM’s role in cosmology and astrophysics.