Stellar and dark matter density in the Local Universe

• Published in: Astronomische Nachrichten Vol. 339; no. 7-8; pp. 615 - 622
• Main Authors: Karachentsev, I. D., Telikova, K. N.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH & Co. KGaA 01-08-2018; Wiley Subscription Services, Inc
• Subjects: cosmology: dark matter; Dark matter; Density; Galaxies; galaxies: formation; Universe
• ISSN: 0004-6337; 1521-3994
• DOI: 10.1002/asna.201813520

We calculate the mean density profiles for luminous and dark matter on distance scales D ∼ 1–100 Mpc around us using recent all‐sky catalogs of galaxy groups. Within the Local Volume (D < 11 Mpc), we derived the mean stellar density Ω* = 0.44% in the critical density units and the mean total matter density Ωm = 0.17. Within a sphere of radius 40 Mpc, these quantities drop to Ω* = 0.24–0.32% and Ωm = 0.09–0.14. In a larger volume within D ∼ 135 Mpc, the discussed densities become more uncertain: Ω* = 0.20–0.24% and Ωm = 0.05–0.16. We summarize that the major part of the cosmic dark matter is located outside the virial and collapsing zones of groups and clusters.