Network analysis of the COSMOS galaxy field

Robin De Regt, Stepan Apunevych, Christian Von Ferber, Yu Holovatch, Bohdan Novosyadlyj

    Research output: Contribution to journalArticlepeer-review

    8 Citations (Scopus)
    31 Downloads (Pure)


    The galaxy data provided by COSMOS survey for 1° × 1° field of sky are analysed by methods of complex networks. Three galaxy samples (slices) with redshifts ranging within intervals 0.88÷0.91, 0.91÷0.94 and 0.94÷0.97 are studied as two-dimensional projections for the spatial distributions of galaxies. We construct networks and calculate network measures for each sample, in order to analyse the network similarity of different samples, distinguish various topological environments, and find associations between galaxy properties (colour index and stellar mass) and their topological environments. Results indicate a high level of similarity between geometry and topology for different galaxy samples and no clear evidence of evolutionary trends in network measures. The distribution of local clustering coefficient C manifests three modes which allow for discrimination between stand-alone singlets and dumbbells (0 ≤ C ≤ 0.1), intermediately packed (0.1 < C < 0.9) and clique (0.9 ≤ C ≤ 1) like galaxies. Analysing astrophysical properties of galaxies (colour index and stellar masses), we show that distributions are similar in all slices, however weak evolutionary trends can also be seen across redshift slices. To specify different topological environments we have extracted selections of galaxies from each sample according to different modes of C distribution. We have found statistically significant associations between evolutionary parameters of galaxies and selections of C: the distribution of stellar mass for galaxies with interim C differ from the corresponding distributions for stand-alone and clique galaxies, and this difference holds for all redshift slices. The colour index realises somewhat different behaviour.
    Original languageEnglish
    Pages (from-to)4738–4748
    JournalMonthly Notices of the Royal Astronomical Society
    Issue number4
    Early online date28 Mar 2018
    Publication statusPublished - Jul 2018


    • cosmology
    • large-scale structure of the Universe
    • galaxy evolution


    Dive into the research topics of 'Network analysis of the COSMOS galaxy field'. Together they form a unique fingerprint.

    Cite this