Is the local supercluster a physical association

Journal Article · Thu Jan 01 04:00:00 EST 1976 · Astrophys. J., v. 203, no. 1, pp. 23-32

DOI:https://doi.org/10.1086/154043· OSTI ID:4029149

Bahcall, J N; Joss, P C

The nearby bright galaxies appear to be concentrated toward a particular great circle on the sky. This distribution has been previously interpreted as implying that our Galaxy is a member of a local supercluster. A quantitative measure of the degree of concentration of a sample of galaxies toward any great circle is described and applied to the Shapley-Ames and de Vaucouleurs catalogs of bright galaxies as well as to computer-simulated catalogs of galaxies. It is found that the observed distribution can be explained as the combined result of obscuration by our own Galaxy, purely local clustering on angular scales approximately-less-than10degree, and our proximity to a rather large and populous cluster, the Virgo cluster. In order for this interpretation to be correct, the Virgo cluster must have a mean angular radius of the order of or greater than 15degree. This interpretation is supported by recent measurements that do not indicate any large inhomogeneities in the motions of nearby galaxy clusters and that show that the mean recessional velocity of the Virgo cluster is consistent with a uniform Hubble expansion. If this interpretation is correct, it may be possible to determine the Hubble constant directly from measurements of individual distance indicators (such as H ii regions and the brightest stars) with distance moduli approximately-less-than32. Further radial velocity measurements of many nearby galaxies would probably enable one to distinguish between the presently conventional hypothesis of a local supercluster and the suggestion of a moderately large Virgo cluster combined with other selction effects. (AIP)

• Research Organization: Institute for Advanced Study
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-030778
• OSTI ID: 4029149
• Journal Information: Astrophys. J., v. 203, no. 1, pp. 23-32, Journal Name: Astrophys. J., v. 203, no. 1, pp. 23-32; ISSN ASJOA
• Country of Publication: United States
• Language: English

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