Large Scale Structure at High Redshift: Correlated Absorption Toward the QSO Pair Tol~1037-2704 and Tol~1038-2712?
Session 115 -- Cosmology and Dark Matter
Oral presentation, Saturday, January 15, 10:15-11:45, Salon III Room (Crystal Gateway)

## [115.07] Large Scale Structure at High Redshift: Correlated Absorption Toward the QSO Pair Tol~1037-2704 and Tol~1038-2712?

N.Dinshaw, C.D.Impey (Steward Observatory)

We present high resolution ($\sim$~0.15~\AA) echelle spectra of the wide QSO pair Tol~1037-2704 ($z_{\rm em}=2.193$) and Tol~1038-2712 ($z_{\rm em}=2.331$) as well as two neighbouring quasars from the Bohuski and Weedman survey. The components of the Tololo pair are separated by 17.9\,$^\prime$ or $\sim$~4.3~$h^{-1}_{100}$~Mpc for $q_0 = 0.5$, and exhibit a large number of apparently correlated C {\sc iv} absorption systems over scales corresponding to supercluster dimensions. We confirm the existence of the five absorption complexes reported by Jakobsen et al. and Sargent and Steidel, and find additional complexes, many of which are split into multiple components with $\Delta v\simeq 100-1000$~km/s. This brings the total number of C {\sc iv} absorption systems to 22 in Tol~1037-2704 and 13 in Tol~1038-2712 between redshifts $z_{\rm abs}=1.48$ and $z_{\rm abs} = 2.14$, well above the expectation from Poisson statistics. Two neighbouring quasars, located $\sim$~40\,$^\prime$ ($D \simeq 9.6$~$h^{-1}_{100}$~Mpc) southeast and $\sim$~150\,$^\prime$ ($D \simeq 36$~$h^{-1}_{100}$~Mpc) east of the Tololo pair, have also been observed with the aim of searching for absorption associated with the putative supercluster. Both QSOs show an excess of C {\sc iv} absorption systems, of which three match complexes in the original quasar pair. We consider the hypothesis that the various redshift matches are caused by an intervening supercluster and present the spatial correlation function of the 47 C {\sc iv} absorption systems in the 4 quasars in order to constrain the scale of the clustering. The inferred dimensions of the hypothetical supercluster are at least 40~$h^{-1}_{100}$~Mpc on the plane of the sky and about 60~$h^{-1}_{100}$~Mpc along the line of sight.