The Corona Borealis supercluster: connectivity, collapse, and evolution
| Autor: | Peeter Tenjes, Pekka Heinämäki, Heidi Lietzen, Rain Kipper, Jaan Einasto, Lauri Juhan Liivamägi, Pasi Nurmi, Antti Tamm, Elmo Tempel, Maret Einasto |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) Mass distribution 010308 nuclear & particles physics media_common.quotation_subject FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies 01 natural sciences Redshift Universe Galaxy Space and Planetary Science Supercluster Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences Content (measure theory) Density contrast 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Galaxy cluster Astrophysics - Cosmology and Nongalactic Astrophysics media_common |
| Zdroj: | Astronomy & Astrophysics. 649:A51 |
| ISSN: | 1432-0746 0004-6361 |
| Popis: | We present a study of the Corona Borealis (CB) supercluster. We determined the high-density cores of the CB and the richest galaxy clusters in them, and studied their dynamical state and galaxy content. We determined filaments in the supercluster to analyse the connectivity of clusters. We compared the mass distribution in the CB with predictions from the spherical collapse model and analysed the acceleration field in the CB. We found that at a radius $R_{\mathrm{30}}$ around clusters in the CB (A2065, A2061, A2089, and Gr2064) (corresponding to the density contrast $\Delta\rho \approx 30$), the galaxy distribution shows a minimum. The $R_{30}$ values for individual clusters lie in the range of $3 - 6$ $h^{-1}$ Mpc. The radii of the clusters (splashback radii) lie in the range of $R_{\mathrm{cl}} \approx 2 - 3$ $R_{\mathrm{vir}}$. The projected phase space diagrams and the comparison with the spherical collapse model suggest that $R_{\mathrm{30}}$ regions have passed turnaround and are collapsing. Galaxy content in clusters varies strongly. The cluster A2061 has the highest fraction of galaxies with old stellar populations, and A2065 has the highest fraction of galaxies with young stellar populations. The number of long filaments near clusters vary from one at A2089 to five at A2061. During the future evolution, the clusters in the main part of the CB may merge and form one of the largest bound systems in the nearby Universe. Another part of the CB, with the cluster Gr2064, will form a separate system. The structures with a current density contrast $\Delta\rho \approx 30$ have passed turnaround and started to collapse at redshifts $z \approx 0.3 - 0.4$. The comparison of the number and properties of the most massive collapsing supercluster cores from observations and simulations may serve as a test for cosmological models. Comment: 24 pages, 17 figures, accepted for publication in A&A, references updated |
| Databáze: | OpenAIRE |
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