Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-25T16:26:31.914Z Has data issue: false hasContentIssue false

Dwarfs in the entourage of the Local Volume groups: flow tracers and cosmological probes

Published online by Cambridge University Press:  30 October 2019

Olga Kashibadze
Affiliation:
Special Astrophysical Observatory of RAS, Nizhnij Arkhyz, Russia
Igor Karachentsev
Affiliation:
Special Astrophysical Observatory of RAS, Nizhnij Arkhyz, Russia
Valentina Karachentseva
Affiliation:
Main Astronomical Observatory of NASU, Kyiv, Ukraine
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

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) × 1012M. 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.

Type
Contributed Papers
Copyright
© International Astronomical Union 2019 

References

Abazajian, K. N., Adelman-McCarthy, J. K., Agüeros, M. A. et al . 2009, ApJS, 182, 543 CrossRefGoogle Scholar
Chernin, A. D., Bisnovatyi-Kogan, G. S., Teerikorpi, P. et al . 2013, A&A, 553, A101 Google Scholar
Koposov, S. E., Belokurov, V., Torrealba, G., Wyn, E. N. 2015, ApJ, 805, 130 CrossRefGoogle Scholar
Kroupa, P. 2014, arXiv:1409.6302Google Scholar
Planck Collaboration, XVI. 2014, A&A, 571, A16 Google Scholar
Tonry, J. L., Stubbs, C. W., Lykke, K. R. et al . 2012, ApJ, 750, 99 CrossRefGoogle Scholar