Proceedings of a workshop held at Ringberg Castle, Tegernsee, Germany, 15-19 September 1997 / Hermann-Josef Röser, Klaus Meisenheimer, eds. Berlin ; New York : Springer, 1999.

For a PDF version of the article, click here.


Bruno Binggeli

Astronomical Institute of the University of Basel, Venusstrasse 7, CH-4102 Binningen, Switzerland

ABSTRACT. Our current understanding of the structure and dynamics of the Virgo cluster is reviewed. Special emphasis is given to a possible connection between the activity of M87 and the cluster as a whole. The Virgo cluster is an aggregate of at least three separate subclusters, centered on M87, M86, and M49. The dominant M87 subclump, with a mass of a few 1014 Msun, is outweighing the other two subclumps by an order of magnitude. There is evidence, from the kinematics of dwarf galaxies and the structure of the X-ray gas, that the M86 subclump is falling into the M87 subclump from the back with a relative velocity of approx 1500 km s-1. M87 and M86 seem to be embedded in a common, cocoon-like swarm of dwarf ellipticals. The orientation of this cocoon, or simply the line connecting M87 and M86, is coinciding with the (projected) direction of the jet of M87. A possible explanation for this apparent coherence between structures on the pc scale of the center of M87 and the Mpc scale of the Virgo cluster is discussed.

Table of Contents