Large Scale Structure: Setting the Stage for the Galaxy Formation Saga

Abstract

Over the past three decades the established view of a nearly homogeneuous, featureless Universe on scales larger than a few Megaparsec has been completely overhauled. In particular through the advent of ever larger galaxy redshift surveys we were revealed a galaxy distribution displaying an intriguing cellular pattern in which filamentary and wall-like structures, as well as huge regions devoid of galaxies, are amongst the most conspicuous morphological elements. In this contribution we will provide an overview of the present observational state of affairs concerning the distribution of galaxies and the structure traced out by the matter distribution in our Universe. In conjunction with the insight on the dynamics of the structure formation process obtained through the mapping of the peculiar velocities of galaxies in our local Universe and the information on the embryonic circumstances that prevailed at the epoch of Recombination yielded by the various Cosmic Microwave Background experiments, we seek to arrive at a more or less compelling theoretical framework of structure formation.The main aspects of this framework of the rise of structure through gravitational instability can probably be most readily appreciated through illustrative examples of various scenarios, as for instance provided by some current state-of-the-art N-body simulations. We will subsequently wrap up the observational and theoretical evidence for the emergence and evolution of structure in the Universe by sketching the stage for the ultimate Holy Grail of late 20th century astrophysics, understanding the saga of the formation of what arguably are the most prominent and at the same time intoxicatingly beautiful and intriguing denizens of our Cosmos, the {\it galaxies}.Comment: 25 pages, 7 figures. Invited Review at `The most distant radio galaxies' KNAW Colloquium, Amsterdam, October 1997, eds Best et al., Kluwer. 25 pages of LaTex including 7 postscript (bitmapped) figures. Uses knawproc.cl