Local dark energy: HST evidence from the expansion flow around Cen A/M83 galaxy group

Abstract

A structure with a massive group in its centre and a cool expansion outflow outside is studied around the Cen A galaxy with the use of the Hubble Space Telescope observations. It is demonstrated that the dynamics of the flow is dominated by the antigravity of the dark energy background. The density of dark energy in the area is estimated to be near the global cosmological density. This agrees with previous results from the neighbourhood of the Local Group. A notion of the ‘Hubble cell’ is introduced as a building block of the local structure of the universe.

Keywords:

• Groups of galaxies
• the Hubble flow
• Dark energy

Acknowledgements

The work of A.C., V.D. and L.D. was partly supported by a RFBR grant 06-02-16366.