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Related papers: Peculiar Velocities and the Mean Density Parameter

200 papers

Using the nearly full sky Ks=11.75 2MASS Redshift Survey [2MRS]of ~45,000 galaxies we reconstruct the underlying peculiar velocity field and constrain the cosmological bulk flow within ~100. These results are obtained by maximizing the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Enzo Branchini , Marc Davis , Adi Nusser

We compare the peculiar velocities derived from the I-band Tully-Fisher (TF) relation for 989 field spiral galaxies in the SFI catalogue with the predicted velocity field derived from the IRAS PSCz galaxy redshift survey. We assume linear…

Cosmological parameters can be measured by comparing peculiar velocities with those predicted from a galaxy density field. Previous work has tested the accuracy of this approach with N-body simulations, but generally on idealised mock…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-27 Amber M. Hollinger , Michael J. Hudson

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…

The detailed nature of dark energy remains a mystery, leaving the possibility that its effects might be explained by changes to the laws of gravity on large scales. The peculiar velocities of galaxies directly trace the strength of gravity…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-29 Stuart Lyall , Chris Blake , Ryan J. Turner

The 2MFGC catalog we have used contains 18020 galaxies selected from the extended objects in the 2MASS infrared sky survey as having apparent ratios of the axes b/a<0.3. Most of them are spiral galaxies of later morphological types whose…

Astrophysics · Physics 2008-11-26 I. D. Karachentsev , Yu. N. Kudrya , V. E. Karachentseva , S. N. Mitronova

What is the role of clusters of galaxies in probing the large-scale velocity field of the universe? We investigate the distribution of peculiar velocities of clusters of galaxies in the popular low-density ($\Omega=0.3$) flat…

Astrophysics · Physics 2009-10-22 Neta A. Bahcall , Renyue Cen , Mirt Gramann

We present an analysis of the two-point peculiar velocity correlation function using data from the CosmicFlows catalogues. The Millennium and MultiDark Planck 2 N-body simulations are used to estimate cosmic variance and uncertainties due…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-24 Yuyu Wang , Christopher Rooney , Hume A. Feldman , Richard Watkins

Peculiar velocity measurements constrain the parameter combination $f\sigma_8$, the product of the linear growth rate $f$ and the fluctuation amplitude $\sigma_8$. Under the approximation that $f$ is a monotonic function of $\Omega_{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-25 Richard Stiskalek

We derive peculiar velocities for the 6dF Galaxy Survey (6dFGS) and describe the velocity field of the nearby ($z<0.055$) southern hemisphere. The survey comprises 8885 galaxies for which we have previously reported Fundamental Plane data.…

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 a new reconstruction of the mass density and the peculiar velocity fields in the nearby universe using recent measurements of Tully-Fisher distances for a sample of late spirals. We find significant differences between our…

Large-scale peculiar motion modulates the observed luminosity distribution of galaxies. Using about half a million SDSS galaxies, this can be harnessed to obtain bounds on peculiar velocity moments, the amplitude of the linear matter power…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-05 Martin Feix

We present a comparison between the peculiar velocity field measured from the ENEAR all-sky $D_n-\sigma$ catalog and that derived from the galaxy distribution of the IRAS PSCz redshift survey. The analysis is based on a modal expansion of…

Peculiar velocities are an important probe of the mass distribution in the Universe and the growth rate of structure, directly measuring the effects of gravity on the largest scales and providing a test for theories of gravity. Comparing…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-30 Paula Boubel , Matthew Colless , Khaled Said , Lister Staveley-Smith

The cosmological peculiar velocity field (deviations from the pure Hubble flow) of matter carries significant information on dark energy, dark matter and the underlying theory of gravity on large scales. Peculiar motions of galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-17 Adi Nusser , Enzo Branchini , Martin Feix

The line-of-sight peculiar velocities are good indicators of the gravitational fluctuation of the density field. Techniques have been developed to extract cosmological information from the peculiar velocities in order to test the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-08 Fei Qin

We investigate the peculiar velocities predicted for galaxy clusters by theories in the cold dark matter family. A widely used hypothesis identifies rich clusters with high peaks of a suitably smoothed version of the linear density…

We have obtained Tully-Fisher (TF) measurements for some 3000 late-type galaxies in the field and in 76 clusters distributed throughout the sky between 10 and 200\h Mpc. The cluster data are applied to the construction of an I band TF…

Astrophysics · Physics 2007-05-23 Daniel A. Dale , Riccardo Giovanelli

The recent re-evaulation of the peculiar velocity field outside the Local Supercluster (Dekel et al. 1999, ApJ 522) has permitted a re-examination of the origins of the peculiar velocity field within the Local Supercluster using the Mark…

Astrophysics · Physics 2007-05-23 David Burstein