Dwarfs in the entourage of the Local Volume groups: flow tracers and cosmological probes. Issue Volume 14:Issue S344(2019) (August 2018)

• Record Type: Journal Article
• Authors: Kashibadze, Olga; Karachentsev, Igor; Karachentseva, Valentina
• Editors: McQuinn, Kristen B. W.; Stierwalt, Sabrina
• Is Part Of: Proceedings of the International Astronomical Union. Volume 14:Issue S344(2019)
• Page Start: 488
• Page End: 490
• Publication Date: 2018-08
• Subjects: galaxies: distances and redshifts, -- cosmology: observations, -- (cosmology:) large-scale structure of universe, -- (cosmology:) cosmological parameters; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921318005586
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: We consider a sample of dwarf galaxies with accurate distances and velocities around 14 massive groups in the Local Volume. We combine all the data into a single synthetic group, and then determine its radius of the zero-velocity surface, separating it against the global cosmic expansion. Our estimation is derived from fitting the the spherical infall model (including effects of the cosmological constant) to the observational data. We found the optimal value of the radius to be 0.93 ± 0.02 Mpc. Assuming the Planck model parameters, it corresponds to the total mass of the synthetic group (1.6 ± 0.2) × 10 12 M ⊙ . Thus, we obtain the paradoxical result that the total mass of the synthetic group estimated on the scale of 3–4 its virial radius is only 60% of the virial mass estimate. Anyway, we conclude that wide outskirts of the nearby groups do not contain a large amount of hidden mass outside their virial radii.