A&A 372, L57-L60 (2001)
Detection of a redshift 3.04 filamentP. Møller and J. U. Fynbo
European Southern Observatory, Karl-Schwarzschild-Straße 2, 85748 Garching by München, Germany
(Received 17 April 2001 / Accepted 26 April 2001 )
The filamentary structure of the early universe has until now only been seen in numerical simulations. Despite this lack of direct observational evidence, the prediction of early filamentary structure formation in a Cold Dark Matter dominated universe has become a paradigm for our understanding of galaxy assembly at high redshifts. Clearly observational confirmation is required. Lyman Break galaxies are too rare to be used as tracers of filaments and we argue that to map out filaments in the high z universe, one will need to identify classes of objects fainter than those currently accessible via the Lyman Break technique. Objects selected via their Ly emission, and/or as DLA absorbers, populate the faintest accessible part of the high redshift galaxy luminosity function, and as such make up good candidates for objects which will map out high redshift filaments. Here we present the first direct detection of a filament (at z=3.04) mapped by those classes of objects. The observations are the deepest yet to have been done in Ly imaging at high redshift, and they reveal a single string of proto-galaxies spanning about 5 Mpc (20 Mpc comoving). Expanding the cosmological test proposed by Alcock & Paczynski (1979), we outline how observations of this type can be used to determine at z=3.
Key words: galaxies: formation -- galaxies: high-redshift -- quasars: absorption lines -- cosmological parameters -- early Universe -- large-scale structure of Universe
Offprint request: P. Møller, firstname.lastname@example.org
© ESO 2001