Streaming velocities as a dynamical estimator of Omega
It is well known that estimating the pairwise velocity of galaxies, v_{12}, from the redshift space galaxy correlation function is difficult because this method is highly sensitive to the assumed model of the pairwise velocity dispersion. Here we propose an alternative method to estimate v_{12} dire...
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Format: | Journal article |
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1998
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author | Ferreira, P Juszkiewicz, R Feldman, H Davis, M Jaffe, A |
author_facet | Ferreira, P Juszkiewicz, R Feldman, H Davis, M Jaffe, A |
author_sort | Ferreira, P |
collection | OXFORD |
description | It is well known that estimating the pairwise velocity of galaxies, v_{12}, from the redshift space galaxy correlation function is difficult because this method is highly sensitive to the assumed model of the pairwise velocity dispersion. Here we propose an alternative method to estimate v_{12} directly from peculiar velocity samples, which contain redshift-independent distances as well as galaxy redshifts. In contrast to other dynamical measures which determine beta = sigma_8 x Omega^{0.6}, our method can provide an estimate of (sigma_8)^2 x Omega^{0.6} for a range of sigma_8 (here Omega is the cosmological mass density parameter while sigma_8 is the standard normalization parameter for the spectrum of matter density fluctuations). We demonstrate how to measure this quantity from realistic catalogues. |
first_indexed | 2024-03-06T23:02:53Z |
format | Journal article |
id | oxford-uuid:62c7b0aa-a364-403d-bb30-8d988a8215ed |
institution | University of Oxford |
last_indexed | 2024-03-06T23:02:53Z |
publishDate | 1998 |
record_format | dspace |
spelling | oxford-uuid:62c7b0aa-a364-403d-bb30-8d988a8215ed2022-03-26T18:08:25ZStreaming velocities as a dynamical estimator of OmegaJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:62c7b0aa-a364-403d-bb30-8d988a8215edSymplectic Elements at Oxford1998Ferreira, PJuszkiewicz, RFeldman, HDavis, MJaffe, AIt is well known that estimating the pairwise velocity of galaxies, v_{12}, from the redshift space galaxy correlation function is difficult because this method is highly sensitive to the assumed model of the pairwise velocity dispersion. Here we propose an alternative method to estimate v_{12} directly from peculiar velocity samples, which contain redshift-independent distances as well as galaxy redshifts. In contrast to other dynamical measures which determine beta = sigma_8 x Omega^{0.6}, our method can provide an estimate of (sigma_8)^2 x Omega^{0.6} for a range of sigma_8 (here Omega is the cosmological mass density parameter while sigma_8 is the standard normalization parameter for the spectrum of matter density fluctuations). We demonstrate how to measure this quantity from realistic catalogues. |
spellingShingle | Ferreira, P Juszkiewicz, R Feldman, H Davis, M Jaffe, A Streaming velocities as a dynamical estimator of Omega |
title | Streaming velocities as a dynamical estimator of Omega |
title_full | Streaming velocities as a dynamical estimator of Omega |
title_fullStr | Streaming velocities as a dynamical estimator of Omega |
title_full_unstemmed | Streaming velocities as a dynamical estimator of Omega |
title_short | Streaming velocities as a dynamical estimator of Omega |
title_sort | streaming velocities as a dynamical estimator of omega |
work_keys_str_mv | AT ferreirap streamingvelocitiesasadynamicalestimatorofomega AT juszkiewiczr streamingvelocitiesasadynamicalestimatorofomega AT feldmanh streamingvelocitiesasadynamicalestimatorofomega AT davism streamingvelocitiesasadynamicalestimatorofomega AT jaffea streamingvelocitiesasadynamicalestimatorofomega |