English

Surveying the Local Supercluster Plane

Cosmology and Nongalactic Astrophysics 2020-06-28 v1 Astrophysics of Galaxies

Abstract

We investigate the distribution and velocity field of galaxies situated in a band of 100 by 20 degrees centered on M87 and oriented along the Local supercluster plane. Our sample amounts 2158 galaxies with radial velocities less than 2000 km/s. Of them, 1119 galaxies (52%) have distance and peculiar velocity estimates. About 3/4 of early-type galaxies are concentrated within the Virgo cluster core, most of the late-type galaxies in the band locate outside the virial radius. Distribution of gas-rich dwarfs with MHI>MM_{\rm H\,I} > M_* looks to be insensitive to the Virgo cluster presence. Among 50 galaxy groups in the equatorial supercluster band 6 groups have peculiar velocities about 500-1000 km/s comparable with virial motions in rich clusters. The most cryptic case is a flock of nearly 30 galaxies around NGC4278 (Coma I cloud), moving to us with the mean peculiar velocity of -840 km/s. This cloud (or filament?) resides at a distance of 16.1 Mpc from us and approximately 5 Mpc away from the Virgo center. Galaxies around Virgo cluster exhibit Virgocentric infall with an amplitude of about 500 km/s. Assuming the spherically symmetric radial infall, we estimate the radius of the zero-velocity surface to be R0=(7.0±0.3)R_0 = (7.0\pm0.3) Mpc that yields the total mass of Virgo cluster to be (7.4±0.9)×1014M(7.4\pm0.9)\times 10^{14} M_{\odot} in tight agreement with its virial mass estimates. We conclude that the Virgo outskirts does not contain significant amounts of dark mater beyond its virial core.

Keywords

Cite

@article{arxiv.2006.03721,
  title  = {Surveying the Local Supercluster Plane},
  author = {Olga G. Kashibadze and Igor D. Karachentsev and Valentina E. Karachrntseva},
  journal= {arXiv preprint arXiv:2006.03721},
  year   = {2020}
}

Comments

19 pages, 13 figures, 4 tables. Published in Astrophysical Bulletin, Vol.73, pp.124-141 (2018)

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