Kapteyn Colloquium
	Monday, 2 November 2009 Zernikegebouw 161 at 14:00 NOTE SPECIAL TIME!

	Erwin Platen Kapteyn Astronomical Institute

Title:

A Void Perspective of the Cosmic Web

Abstract:

Voids are nearly empty regions in the Universe that can extend to millions of lightyears in size. They are a characteristic part of a complex bubble-like foam called the Cosmic Web. We have developed methods to find such voids and show that they are an integral part of the Large Scale Structure. For example voids may locally be expanding bubbles on global scales they get deformed by strong tidal forces extorted by massive clusters that surround them. These clusters usually cluster into larger agglomerates called superclusters. Also voids cluster, forming extended objects called supervoids. Observations show that these superclusters and supervoids align themselves to form prominent large entities, the Great Walls. Towards smaller scales we are also able to locate the lonely galaxies that reside in the midst of large and almost empty voids. Free from all the complexities in denser regions, the properties of such isolated galaxies tells us a lot about the general formation scenario of galaxies.