vix.ing · top · new · best · stats · spec

A Large Structure of Galaxies At Redshift z~3 and its Cosmological Implications

1997/08/13 by Charles C. Steidel, C. Steidel, Kurt L. Adelberger +9 · 26 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Electrical and Electromagnetic Research #Galaxies: Formation, Evolution, Phenomena #astro-ph

paper · pdf · doi:10.1086/305073

published as Astrophys.J. 492 (1998) 428 · 24 pages including 5 ps figures, LaTeX, uses aaspp4.sty, to appear in the Astrophysical Journal. Also available at ftp://astro.caltech.edu/users/ccs/spike_preprint.ps.gz

arxiv created 1997/08/13 · openalex publication_date 1998/01/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31

Abstract

We report the discovery of a highly significant concentration of galaxies at a redshift of <z>=3.090. The structure is evident in a redshift histogram of photometrically selected ``Lyman break'' objects in a 9' by 18' field in which we have obtained 78 spectroscopic redshifts in the range 2.0 < z <3.4. The dimensions of the structure projected on the plane of the sky are at least 11'by 8', or 14h70-1 by 10h70-1 Mpc (comoving; ΩM=1). The concentration contains 15 galaxies and one faint (R=21.7) QSO. We consider the structure in the context of a number of cosmological models and argue that Lyman-break galaxies must be very biased tracers of mass, with an effective bias on mass scale M~1015M\sun ranging from b~2 for ΩM=0.2 to b >~6 for ΩM=1. In a Cold Dark Matter scenario the large bias values suggest that individual Lyman-break galaxies are associated with dark halos of mass M~1012 M\sun, reinforcing the interpretation of these objects as the progenitors of massive galaxies at the present epoch. Preliminary results of spectroscopy in additional fields suggest that such large structures are common at z~3, with about one similar structure per survey field. The implied space density is consistent with the possibility that we are observing moderately rich clusters of galaxies in their early non-linear evolution. Finally, the spectrum of one of the QSOs discovered in our survey (zem = 3.356) exhibits metal line absorption systems within the 3 redshift bins having the largest number of galaxies in field, z = 2.93, 3.09, and 3.28. These results are the first from an ongoing ``targeted'' redshift survey designed to explore the nature and distribution of star-forming galaxies in the redshift range 2.7 <~ z <~ 3.4.

Cited by