The correlation of the Lyman-alpha forest in close pairs and groups of high-redshift quasars: clustering of matter on scales 1-5 Mpc

E. Rollinde (1) , P. Petitjean (1) , C. Pichon (2, 1) , S. Colombi (1) , B. Aracil (1) , V. d'Odorico (1) , M. G. Haehnelt

1 IAP - Institut d'Astrophysique de Paris
2 ObAS - Observatoire astronomique de Strasbourg

The fluctuating Gunn-Peterson paradigm for the origin of the Lyman-alpha forest is tested by measuring the coherence length of the absorbing structures in real space from the cross-correlation of absorption spectra of a sample of quasars in pairs and groups at z 2 observed with FORS2 and UVES at the UT2 Kuyen ESO telescope. The transverse coherence length is similar to that measured in velocity space from the line of sight correlation function. The comparison of transverse to longitudinal correlation length constrains the cosmological constant to Omega-Λ< 0.9. The larger samples of absorption spectra of QSO pairs with separations of a few arcminutes currently assembled should tighten this rather weak constraint considerably.

Domaines: Planète et Univers [physics]

E. Rollinde, P. Petitjean, C. Pichon, S. Colombi, B. Aracil, et al.. The correlation of the Lyman-alpha forest in close pairs and groups of high-redshift quasars: clustering of matter on scales 1-5 Mpc. SF2A-2002: Semaine de l'Astrophysique Francaise, 2002, à renseigner, Unknown Region. pp.73. ⟨insu-04054629⟩