Constraints on cosmological and biasing models using active galactic nucleus clustering |
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| Authors: | Spyros Basilakos |
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| Institution: | Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2BW |
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| Abstract: | We attempt to put constraints on different cosmological and biasing models by combining the recent clustering results of X-ray sources in the local ( z ≤0.1) and distant Universe ( z ～1) . To this end we compare the measured angular correlation function for bright (Akylas et al.) and faint (Vikhlinin & Forman) ROSAT X-ray sources respectively with those expected in three spatially flat cosmological models. Taking into account the different functional forms of the bias evolution, we find that there are two cosmological models which match the data well. In particular, low-Ω○ cosmological models (ΩΛ=1?Ω○=0.7) that contain either (i) high σ 8mass=1.13 value with galaxy merging bias, b ( z )∝(1+ z )1.8 or (ii) low σ 8mass=0.9 with non-bias, b ( z ) ≡ 1 best reproduce the AGN clustering results, while τ CDM models with different bias behaviour are ruled out at a high significance level. |
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| Keywords: | galaxies: clusters: general cosmology: theory large-scale structure of Universe X-rays: galaxies |
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