ABSTRACT We create a new catalogue of groups and clusters, applying the friends-to-friends method... more ABSTRACT We create a new catalogue of groups and clusters, applying the friends-to-friends method to the 2dF GRS final release. We investigate various selection effects due to the use of a magnitude limited sample. For this purpose we follow the changes in group sizes and mean galaxy number densities within the groups when shifting nearby observed groups to larger distances. We study the distribution of sizes of dark matter haloes in N-body simulations and compare properties of these haloes and the 2dF groups. (6 data files).
Available observational data allow us to discriminate between the visible matter and the dark mat... more Available observational data allow us to discriminate between the visible matter and the dark matter in M 31 and thus to determine the most important parameters of the dark halo (the mass, the radius and the outer extent).
Symposium - International Astronomical Union, 1999
Empirical studies of the Large–Scale Structure in the nearby Universe come in two complementary m... more Empirical studies of the Large–Scale Structure in the nearby Universe come in two complementary modes, namely the investigation of either the distribution of luminous matter or voids: (i) The description of the galaxy and cluster distribution employs correlation functions, clustering analysis, topological methods, et cetera. (ii) The investigation of the empty regions between systems of galaxies uses void probability functions, mean diameters of voids, the compilation of void catalogues, and so forth.
ABSTRACT We create a new catalogue of groups and clusters, applying the friends-to-friends method... more ABSTRACT We create a new catalogue of groups and clusters, applying the friends-to-friends method to the 2dF GRS final release. We investigate various selection effects due to the use of a magnitude limited sample. For this purpose we follow the changes in group sizes and mean galaxy number densities within the groups when shifting nearby observed groups to larger distances. We study the distribution of sizes of dark matter haloes in N-body simulations and compare properties of these haloes and the 2dF groups. (6 data files).
Available observational data allow us to discriminate between the visible matter and the dark mat... more Available observational data allow us to discriminate between the visible matter and the dark matter in M 31 and thus to determine the most important parameters of the dark halo (the mass, the radius and the outer extent).
Symposium - International Astronomical Union, 1999
Empirical studies of the Large–Scale Structure in the nearby Universe come in two complementary m... more Empirical studies of the Large–Scale Structure in the nearby Universe come in two complementary modes, namely the investigation of either the distribution of luminous matter or voids: (i) The description of the galaxy and cluster distribution employs correlation functions, clustering analysis, topological methods, et cetera. (ii) The investigation of the empty regions between systems of galaxies uses void probability functions, mean diameters of voids, the compilation of void catalogues, and so forth.
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Papers by J. Einasto