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Environments of Quasars in the Context of Large-Scale Structure

Ilona K. Söchting·R. G. Clowes·L. E. Campusano
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Abstract

We are looking at quasar environment in the context of large-scale structure (LSS) - a new approach, giving a more informed interpretation of quasar-galaxy correlations. This paper presents our first results for a sample of z ~ 0.3 quasars. We are using Voronoi tessellation applied in colour (B_J - R) slices for the detection of galaxy clusters and the minimal spanning tree (MST) to delineate the large-scale structure. This new cluster-detection method allows us to find reliably galaxy clusters at z < 0.3 from SuperCOSMOS measurements of UK Schmidt plates. By reconstructing the large-scale structure in a relatively narrow redshift band (0.2 < z < 0.3), we show that quasars follow the large-scale structure traced by galaxy clusters. None of the quasars in our radio-quiet sample is located in the central area of a galaxy cluster. Two quasars, found in a very rich environment, are actually located between two very close galaxy clusters, consistent with results on z ~ 1 quasars suggesting that cluster merg ers may be involved in one of the quasar formation mechanisms.

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Ilona K. Söchting, R. G. Clowes, L. E. Campusano. 2001-11-06. Environments of Quasars in the Context of Large-Scale Structure. https://arxiv.org/abs/astro-ph/0111115

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