Large-Scale Structures in the Early Universe

Large-scale structures in the early universe are also larger than expected. Like the presence of surprisingly early mature galaxies at a redshift of about 2 (see the item above) another result at the AAS meeting suggests that the standard cosmological model---or at least that part of it devoted to galaxy formation---is in need of revision.

A group of astronomers using the Blanco Telescope of the Inter-American Observatory in Chile and the Anglo-Australian Telescope in Australia reported seeing a grouping of 37 galaxies, all at a redshift close to 2.38, spread 300 million light years across the sky. Povilas Palunas (University of Texas) said that this constitutes the largest observed structure in the distant universe.

According to models that simulate how the hot diffuse matter of the infant cosmos distilled into a web of knots and filaments, such an immense agglomeration should not have arisen so quickly.

The statistical case for saying that this sampling of bright galaxies (fainter galaxies could not be seen) is truly a coherent structure and not just a chance juxtaposition can be expressed as a probability with 1000-to-1 odds, a likelihood obtained by looking not at the specific arrangement of galaxies themselves but at the daunting amount of void between the galaxies.

Gerard Williger (Johns Hopkins) said that he and his colleagues would naturally like next to sample adjoining volumes of deep space in order to test the proposition that the hasty filimentation of matter seen in this initial data set (the observed galaxies lie in the southern constellation "Grus") is not an isolated incident (See Goddard news release).