Publication Date:
2020-04-03
Description:
We present a new model for the cross-covariance between galaxy redshift-space distortions and peculiar velocities. We combine this with the autocovariance models of both probes in a fully self-consistent, maximum-likelihood method, allowing us to extract enhanced cosmological parameter constraints. When applying our method to the 6-degree Field Galaxy Survey (6dFGS), our constraint on the growth rate of structure is $fsigma _8 = 0.384 pm 0.052
m {(stat)} pm 0.061
m {(sys)}$ and our constraint for the redshift-space distortion parameter is $ eta = 0.289^{+0.044}_{-0.043}
m {(stat)} pm 0.049
m {(sys)}$. We find that the statistical uncertainty for the growth rate of structure is reduced by 64 per cent when using the complete covariance model compared to the redshift-space distortion autocovariance model and 50 per cent when compared to using the peculiar-velocity autocovariance model. Our constraints are consistent with those from the literature on combining multiple tracers of large-scale structure, as well as those from other 6dFGS analyses. Our measurement is also consistent with the standard cosmological model.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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