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For refcode 1997AJ....113..483R:
Retrieve 406 NED objects in this reference.
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1997AJ....113..483R GROUPS OF GALAXIES IN THE NORTHERN CfA REDSHIFT SURVEY MASSIMO RAMELLA AND ARMANDO PISANI Osservatorio Astronomico di Trieste, via G. B. Tiepolo, 11, 34131 Trieste, Italy Electronic mail: ramella@oat.ts.astro. iLpisani@oat.ts.astro.it MARGARET J. GELLER Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge. Massachusetts 02138 Electronic mail: mgeller@cfa.harvard.edu Received 1996 April 26; revised 1996 November 18 ABSTRACT We use a friends-of friends algorithm to identify loose groups from the northern CfA2 survey covering the region 8^h^ <= {alpha}_1950_ <= 17^h^ and 8.5^deg^ < {delta}_1950_ <= 44.5^deg^. There are 406 groups; 149 of these contains five or more members within the survey. Geometric simulations guide our choice of the selection parameters; {delta}{rho}/{rho} = 8O is the limiting density contrast and V_0_ = 350 km s^-1^ is the fiducial velocity linking parameter. The geometric simulations are particularly important for evaluating the impact of large-scale structure (e.g., the Great Wall) on group selection. The physical parameters of this large sample are coincident with our earlier results (126 groups in Ramella et al. ApJ, 344,522(1989)]: the median velocity dispersion in 192(156; 229) km s^-1^ and the median blue log(M/L) is 2.38 (2.20; 2.52). The mass-to-light ratio (M/L) is in units of M_sun_/L_sun_ for an assumed Hubble constant, H_0_ = 100 km/s/Mpc. The numbers in parentheses are 99% confidence limits. This group catalog provides a substantially larger sample for statistical studies than has been previously available. For example, it provides a more substantial sample for estimation of the distribution of group velocity dispersions and of the group-group correlation function.
Retrieve 406 NED objects in this reference.
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