No CrossRef data available.
Published online by Cambridge University Press: 06 October 2005
We investigate the 3-D matter distribution at $z\sim 2$ with high resolution ($R\sim 40,000$) spectra of QSO pairs and groups obtained with the UVES spectrograph at ESO VLT. Our sample is unique for the number density of objects and the variety of separations, between $\sim 0.5$ and 7 proper Mpc. We compute the real space cross-correlation function of the Lyman-$\alpha$ forest transmitted fluxes. There is a significant clustering signal up to $\sim 2$ proper Mpc, which is still present when absorption lines with high column density ($\log N \ge 13.8$) are excluded.