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We present a self consistent nonparametric model of the local cosmic velocity field based on the density distribution in the PSCz redshift survey of IRAS galaxies. The error analysis, carried out on mock PSCz catalogues constructed from…

We present the results for the predicted density and peculiar velocity fields and the dipole from the PSCz survey of 15,000 IRAS galaxies over 84% of the sky. We find a significant component to the dipole arising between 6000 and 15,000…

We summarise results for the predicted density and peculiar velocity fields from the PSCz survey. We have used a generalisation of the Path Interchange Zeldovich Approximation to determine the velocity field; the most remarkable feature…

We apply a new algorithm, called the Unbiased Minimal Variance (hereafter UMV) estimator, to reconstruct the cosmic density and peculiar velocity fields in our local universe from the SEcat catalog of peculiar velocities comprising both…

Astrophysics · Physics 2009-11-07 Saleem Zaroubi , Enzo Branchini , Yehuda Hoffman , Luiz N. da Costa

We present the reconstructed real-space density and the predicted velocity fields from the Two Mass Redshift Survey (2MRS). The 2MRS is the densest all-sky redshift survey to date and includes about 23,200 galaxies with extinction corrected…

We constructed a Bayesian hyper-parameter statistical method to quantify the difference between predicted velocities derived from the observed galaxy distribution in the \textit{IRAS}-PSC$z$ redshift survey and peculiar velocities measured…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Yin-Zhe Ma , Enzo Branchini , Douglas Scott

Using a dynamical 3-D reconstruction procedure we estimate the peculiar velocities of $R\ge0$ Abell/ACO galaxy clusters from their measured redshift within 25000 km/sec. The reconstruction algorithm relies on the linear gravitational…

Astrophysics · Physics 2009-10-28 Enzo Branchini , Manolis Plionis , Dennis W. Sciama

The density and velocity fields as extracted from the Abell/ACO clusters are compared to the corresponding fields recovered by the POTENT method from the Mark~III peculiar velocities of galaxies. In order to minimize non-linear effects and…

Astrophysics · Physics 2009-10-31 E. Branchini , I. Zehavi , M. Plionis , A. Dekel

We utilise the method of Wiener reconstruction with spherical harmonics and Bessel functions to recover the density and velocity fields from the IRAS 1.2Jy redshift survey. The results are robust to changes in prior parameters and the…

Astrophysics · Physics 2015-06-24 Matthew Webster , Ofer Lahav , Karl Fisher

Starting from the observed redshift distribution of a volume limited Abell/ACO cluster sample we use a 2-step procedure to recover their distances and peculiar velocities (assuming linear theory and linear biasing). The resulting 3D dipole…

Astrophysics · Physics 2007-05-23 E. BRANCHINI , M. PLIONIS

The reconstruction of the large scale velocity field from the grouped Cosmicflows-4 (CF4) database is presented. The lognormal bias of the inferred distances and velocities data is corrected by the Bias Gaussianization correction (BGc)…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-03 Yehuda Hoffman , Aurélien Valade , Noam I. Libeskind , Jenny G. Sorce , R. Brent Tully , Simon Pfeifer , Stefan Gottlöber , Daniel Pomaréde

We present a maximum probability approach to reconstructing spatial maps of the peculiar velocity field at redshifts $z\sim0.1$, where the velocities have been measured from distance indicators (DI) such as $D_n-\sigma$ relations or…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Russell Johnston , David Bacon , Luis F. A. Teodoro , Robert C. Nichol , Michael S. Warren , Catherine Cress

Large-scale Fourier modes of the cosmic density field are of great value for learning about cosmology because of their well-understood relationship to fluctuations in the early universe. However, cosmic variance generally limits the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Omar Darwish , Simon Foreman , Muntazir M. Abidi , Tobias Baldauf , Blake D. Sherwin , P. Daniel Meerburg

Joint analyses of the large-scale distribution of galaxies, and their motions under the gravitational influence of this density field, allow powerful tests of the cosmological model, including measurement of the growth rate of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-14 Chris Blake , Ryan J. Turner

We present a generalized version of the Path Interchange Zel'dovich Approximation (PIZA; Croft and Gaztanaga 1997; hereafter CG97), which may be used to reconstruct density and velocity fields from realistic galaxy redshift surveys. The…

Astrophysics · Physics 2007-05-23 Helen E. M. Valentine , Will Saunders , Andy Taylor

We present a self-consistent nonparametric model of the cosmic velocity field based on the spatial distribution of IRAS galaxies in the recently completed all-sky PSC$z$ redshift survey. The most streaking feature of the PSCz model velocity…

Starting from the observed distribution of galaxy clusters in redshift space we use a two--step procedure to recover their distances and peculiar velocities. After statistically correcting for the unobserved cluster distribution in the zone…

Astrophysics · Physics 2016-08-30 E. Branchini , M. Plionis

In reconstruction analysis of galaxy redshift surveys, one works backwards from the observed galaxy distribution to the primordial density field in the same region, then evolves the primordial fluctuations forward in time with an N-body…

Astrophysics · Physics 2016-08-30 Vijay K. Narayanan , David H. Weinberg

We present an alternative, Bayesian method for large-scale reconstruction from observed peculiar velocity data. The method stresses a rigorous treatment of the random errors and it allows extrapolation into poorly sampled regions in real…

Astrophysics · Physics 2009-10-31 Saleem Zaroubi , Yehuda Hoffman , Avishai Dekel
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