Cosmology with clusters of galaxies

✍ Scribed by Neta A. Bahcall

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 710 KB
• Volume: 138
• Category: Article
• ISSN: 0920-5632
• DOI: 10.1016/j.nuclphysbps.2004.11.003

✦ Synopsis

Rich clusters of galaxies, the largest virialized systems known, place some of the most powerful constraints on cosmology. I discuss below the use of clusters of galaxies in determining two fundamental properties of the universe: the mass-density of the universe, and the distribution of dark matter. I show that several independent methods utilizing clusters of galaxies --cluster dynamics and the mass-to-light function, baryon fraction in clusters, and cluster abundance and its evolution --all indicate the same result: a universe with a low massdensity, ~20% of the critical density needed to halt the universal expansion, and a mass distribution that approximately traces light on large scales.