Cosmological implications of the PSCz PDF and its moments |
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Authors: | Manolis Plionis Spyros Basilakos |
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Institution: | 1Institute of Astronomy &Astrophysics, National Observatory of Athens, I. Metaxa &B. Pavlou, Palaia Penteli, Athens 152 36, Greece;2Astrophysics Group, Imperial College of Science, Technology and Medicine, Blackett Laboratory, Prince Consort Road, London SW7 2BW |
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Abstract: | We compare the probability density function (PDF) and its low-order moments (variance and skewness) of the smoothed IRAS Point Source Catalogue Redshift Survey (PSC z ) galaxy density field and of the corresponding simulated PSC z look-alikes, generated from N -body simulations of six different dark matter models: four structure-normalized with and , one COBE -normalized, and the old standard cold dark matter model. The galaxy distributions are smoothed with a Gaussian window at three different smoothing scales, , 10 and 15 h −1 Mpc. We find that the simulation PSC z look-alike PDFs are sensitive only to the normalization of the power spectrum, probably owing to the shape similarity of the simulated galaxy power spectrum on the relevant scales. We find that the only models that are consistent, at a high significance level, with the observed PSC z PDF are models with a relatively low power spectrum normalization . From the phenomenologically derived σ 8–moments relation, fitted from the simulation data, we find that the PSC z moments suggest . |
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Keywords: | galaxies: general cosmology: theory dark matter large-scale structure of Universe infrared: galaxies |
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