Fundamental plane distances and peculiar velicities of 140 groups and clusters of galaxies at low redshifts: the Hubble diagram

We used the fundamental plane (FP) of early-type galaxies (data from the Sloan Digital Sky Survey) to measure the relative distances and peculiar velocities of 140 groups and clusters of galaxies at low redshifts ( z0.12). We have constructed the Hubble diagram between the distances of galaxy groups/clusters and their radial velocities in the CMB reference frame in the flat ΛCDM model ( Ωm=0.3, H0=70km · s –1 Mpc –1 ). We found that the standard logarithmic scatter of groups and clusters of galaxies on the Hubble diagram (minus peculiar velocities) is ± 0.0173 ( N = 140), which corresponds to the deviation of the Hubble constant 70 ± 2.8 km · s –1 Mpc –1 . For a sample of galaxy systems ( N = 63) with X-ray luminosity in the interval 0.151÷4×1044erg/s we got 70 ± 2.1 km · s –1 Mpc –1 . The standard deviations of peculiar velocities with quadratic allowance for errors are equal to null714 ± 7 km/s and 600 ± 7 km/s, respectively. Five large superclusters of galaxies from the SDSS region show an average peculiar velocity relative to the CMB reference frame +240 ± 250 km/s. We did not detect the outflow of galactic systems from the void (Giant Void, α≈13h, δ≈40°, z≈0.107) formed by groups and clusters of galaxies.