Galaxy groups in the low-redshift Universe Article Swipe
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· 2017
· Open Access
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· DOI: https://doi.org/10.1093/mnras/stx1462
· OA: W2623136699
We apply a halo-based group finder to four large redshift surveys, the 2MRS,\n6dFGS, SDSS and 2dFGRS, to construct group catalogs in the low-redshift\nUniverse. The group finder is based on that of Yang et al. but with an improved\nhalo mass assignment so that it can be applied uniformly to various redshift\nsurveys of galaxies. Halo masses are assigned to groups according to proxies\nbased on the stellar mass/luminosity of member galaxies. The performances of\nthe group finder in grouping galaxies according to common halos and in halo\nmass assignments are tested using realistic mock samples constructed from\nhydrodynamical simulations and empirical models of galaxy occupation in dark\nmatter halos. Our group finder finds $\\sim 94\\%$ of the correct true member\ngalaxies for $90-95\\%$ of the groups in the mock samples; the halo masses\nassigned by the group finder are un-biased with respect to the true halo\nmasses, and have a typical uncertainty of $\\sim0.2\\,{\\rm dex}$. The properties\nof group catalogs constructed from the observational samples are described and\ncompared with other similar catalogs in the literature.\n
