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Related papers: Peculiar Velocities and the Mean Density Parameter

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Peculiar velocity surveys, which measure galaxy peculiar velocities directly from standard candles in addition to redshifts, can provide strong constraints on the linear growth rate of cosmological large-scale structure at low redshift. The…

We investigate methods to best estimate the normalisation of the mass density fluctuation power spectrum (sigma_8) using peculiar velocity data from a survey like the Six degree Field Galaxy Velocity Survey (6dFGSv). We focus on two…

We have measured the cosmic momentum power spectrum from the peculiar velocities of galaxies in the SFI sample. The SFI catalog contains field spiral galaxies with radial peculiar velocities derived from the I-band Tully-Fisher relation. As…

Astrophysics · Physics 2009-11-13 Chan-Gyung Park , Changbom Park

Galaxy peculiar velocities provide an integral source of cosmological information that can be harnessed to measure the growth rate of large scale structure and constrain possible extensions to General Relativity. In this work, we present a…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-30 Ryan J. Turner , Chris Blake , Rossana Ruggeri

We present a simple model for the shape of the distribution function of galaxy peculiar velocities. We show how both nonlinear and linear theory terms combine to produce a distribution which has an approximately Gaussian core with…

Astrophysics · Physics 2009-10-31 Ravi K. Sheth , Antonaldo Diaferio

A promising method for measuring the cosmological parameter combination fsigma_8 is to compare observed peculiar velocities with peculiar velocities predicted from a galaxy density field using perturbation theory. We use N-body simulations…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Amber M. Hollinger , Michael J. Hudson

We compare the peculiar velocities measured in the SBF Survey of Galaxy Distances with the predictions from the density fields of the IRAS 1.2 Jy flux-limited redshift survey and the Optical Redshift Survey (ORS) to derive simultaneous…

Astrophysics · Physics 2009-10-31 J. P. Blakeslee , M. Davis , J. L. Tonry , A. Dressler , E. A. Ajhar

We present a comparison between the peculiar velocity fields measured from the SFI all-sky Sbc-Sc Tully-Fisher catalog and that derived from the \iras 1.2 Jy redshift survey galaxy distribution. The analysis is based on the expansion of…

When measuring the value of the Hubble parameter, $H_0$, it is necessary to know the recession velocity free of the effects of peculiar velocities. In this work, we study different models of peculiar velocity in the local Universe. In…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-18 Supranta S. Boruah , Michael J. Hudson , Guilhem Lavaux

We present results of a statistical analysis of the SFI catalog of peculiar velocities, a recently completed survey of spiral field galaxies with I-band Tully-Fisher distances (Haynes et al. 1999). The velocity field statistic utilized is…

We analyze the cosmic peculiar velocity field as traced by a sample of 1184 spiral, elliptical and S0 galaxies, grouped in 704 objects. We perform a statistical analysis, by calculating the bulk flow, Cosmic Mach Number and velocity…

Astrophysics · Physics 2009-10-22 Lauro Moscardini , Giuseppe Tormen , Sabino Matarrese , Francesco Lucchin

Based on data for 102 OB3 stars with known proper motions and radial velocities, we have tested the distances derived by Megier et al. from interstellar Ca II spectral lines. The internal reconciliation of the distance scales using the…

Astrophysics of Galaxies · Physics 2011-06-30 Vadim Bobylev , Anisa Bajkova

We use an all--sky, complete sample of nearby galaxies, extracted from the LEDA data base, to map the optical galaxy density field in the nearby universe. In order to determine this field, we correct the redshift--dependent distances by…

Astrophysics · Physics 2007-05-23 C. Marinoni , G. Giuricin , B. Costantini , P. Monaco

The power spectrum (PS) of mass density fluctuations, in the range $0.05 \leq k \leq 0.2 \ihmpc$, is derived from the Mark III catalog of peculiar velocities of galaxies, independent of ``biasing". It is computed from the density field as…

Astrophysics · Physics 2016-08-30 Tsafrir Kolatt , Avishai Dekel

We show that a regression of unsmoothed peculiar velocity measurements against peculiar velocities predicted from a smoothed galaxy density field leads to a biased estimate of the cosmological density parameter Omega, even when galaxies…

Astrophysics · Physics 2009-10-31 Andreas A. Berlind , Vijay K. Narayanan , David H. Weinberg , .

We propose to use the flux variability of lensed quasar images induced by gravitational microlensing to measure the transverse peculiar velocity of lens galaxies over a wide range of redshift. Microlensing variability is caused by the…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-23 E. Mediavilla , J. Jimenez-Vicente , J. A. Munoz , E. Battaner

We have used the Optical Redshift Survey (ORS; Santiago et al. 1995) to construct the gravity field due to fluctuations in the galaxy density field out to distances of 8000 km/s. At large scales where linear theory applies, the comparison…

We propose a method for measuring the cosmological density parameter $\Omega$ from the statistics of the divergence field, $\theta \equiv H^{-1} \div v$, the divergence of peculiar velocity, expressed in units of the Hubble constant, $H…

Astrophysics · Physics 2015-06-24 F. Bernardeau , R. Juszkiewicz , A. Dekel , F. R. bouchet