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Related papers: Deriving accurate peculiar velocities (even at hig…

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Peculiar velocities are an important probe of the growth rate of mass density fluctuations in the Universe. Most previous studies have focussed exclusively on measuring peculiar velocities at intermediate ($0.2 < z < 1$) redshifts using…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Michael J. Hudson , Stephen J. Turnbull

We consider some aspects of the perturbation to the luminosity distance $d(z)$ that are of relevance for SN1a cosmology and for future peculiar velocity surveys at non-negligible redshifts. 1) Previous work has shown that the correction to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Nick Kaiser , Michael J. Hudson

A hierarchical Bayesian model is applied to the Cosmicflows-3 catalog of galaxy distances in order to derive the peculiar velocity field and distribution of matter within $z \sim 0.054$. The model assumes the $\Lambda$CDM model within the…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-23 R. Graziani , H. M. Courtois , G. Lavaux , Y. Hoffman , R. B. Tully , Y. Copin , D. Pomarède

Stellar Doppler velocimetry determines a star's radial velocity $v_r$ via measurement of a redshift, $z$. At precisions below 10 m s$^{-1}$ conversion between the two quantities is complex, and care must be taken to properly account for the…

Instrumentation and Methods for Astrophysics · Physics 2019-01-14 Jason T. Wright

An observer stationary with respect to comoving coordinates of the expanding universe should find the redshift distribution to be isotropic. However, a peculiar motion of the observer would introduce a dipole anisotropy in the observed…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-15 Ashok K. Singal

We introduce a new estimator of the peculiar velocity of a galaxy or group of galaxies from redshift and distance estimates. This estimator results in peculiar velocity estimates which are statistically unbiased and that have errors that…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Richard Watkins , Hume A. Feldman

Local distance indicators such as standard sirens, in combination with spectroscopic redshift measurements of their host galaxies, allow us to estimate the present-day expansion rate of the Universe parameterised by Hubble's constant, H_0.…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-11 Chris Blake , Ryan J. Turner

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

Predictions for observables involving the cosmological 21-cm background require calculations of spatial correlations of star formation rate densities (SFRDs) which have a nonlinear dependence on the baryon-dark matter relative velocity.…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-18 Ryan Yuran Zhang , Marc Kamionkowski

Peculiar motion introduces systematic variations in the observed luminosity distribution of galaxies. This allows one to constrain the cosmic peculiar velocity field from large galaxy redshift surveys. Using around half a million galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-19 Martin Feix , Adi Nusser , Enzo Branchini

In this work we address the issue of peculiar velocity measurement in a perturbed Friedmann universe using the deviations from measured luminosity distances of standard candles from background FRW universe. We want to show and quantify the…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-23 Farhang Habibi , Shant Baghram , Saeed Tavasoli

Peculiar velocities, obtained from direct distance measurements, are data of choice to achieve constrained simulations of the Local Universe reliable down to a scale of a few Megaparsecs. Unlike redshift surveys, peculiar velocities are…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Jenny G. Sorce , Helene M. Courtois , Stefan Gottloeber , Yehuda Hoffman , R. Brent Tully

Since the cosmic peculiar velocity field depends on small wave-number modes strongly, we cannot probe its universal properties unless we observe a sufficiently large region. We calculate the expected deviation (sample variance) of the…

Astrophysics · Physics 2009-10-30 Naoki Seto , Jun'ichi Yokoyama

Analysis of the peculiar velocities of galaxies should take account of the uncertainties in both redshifts and distances. We show how this can be done by a numerical application of the action principle. The method is applied to an improved…

Astrophysics · Physics 2009-10-31 P. J. E. Peebles , S. D. Phelps , Edward. J. Shaya , R. Brent Tully

In an isotropic and homogeneous Hubble expansion, all transverse motion is peculiar. Like the radial peculiar velocities of galaxies, transverse peculiar velocities are a means to trace the density of matter that does not rely on light…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Jeremy Darling , Alexandra E. Truebenbach

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…

By correcting the redshift--dependent distances for peculiar motions through a number of peculiar velocity field models, we recover the true distances of a wide, all-sky sample of nearby galaxies (~ 6400 galaxies with velocities cz<5500…

Astrophysics · Physics 2009-10-30 C. Marinoni , P. Monaco , G. Giuricin , B. Costantini

We provide a simple method and relevant theoretical analysis for efficiently estimating higher-order lp distances. While the analysis mainly focuses on l4, our methodology extends naturally to p = 6,8,10..., (i.e., when p is even).…

Machine Learning · Computer Science 2012-03-19 Ping Li , Michael W. Mahoney , Yiyuan She

We study the rms peculiar velocity of clusters as a convenient statistic to put constraints on cosmological models. This statistic is easy to compute theoretically given a model for the power spectrum; we show that with some assumptions it…

Astrophysics · Physics 2016-01-13 Richard Watkins

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
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