Detection of the velocity dipole in the radio galaxies of the NRAO VLA Sky Survey

Abstract

We are in motion against the cosmic backdrop. This motion is evidenced by the systematic temperature shift - or dipole anisotropy - observed in the Cosmic Microwave Background radiation (CMB). Because of the Doppler effect, the temperature of the CMB is 0.1 per cent higher in our direction of motion through the Universe. If our standard cosmological understanding is correct, this dipole should also be present as an enhancement in the surface density of distant galaxies. The main obstacle in finding this signal is the very uneven distribution of nearby galaxies in the Local Supercluster, which drowns out the small cosmological imprint. Here we report the first detection of the expected dipole anisotropy in the galaxy distribution, in a survey of galaxies detected in radio waves. Radio galaxies are mostly located at cosmological distances, so the contamination from nearby clusters should be small. With local radio sources removed, we find a dipole anisotropy in the radio galaxy distribution in the same direction as the CMB, close to the expected amplitude. This result is confirmation of the standard cosmological interpretation of the CMB.

Published in Nature 416, p.150 (12 pages)

References in corpus (5)

• The PSCz Catalogue
• The IRAS PSCz Dipole
• Searching for Large Scale Structure in Deep Radio Surveys
• The 2-10 keV XRB dipole and its cosmological implications
• The CMB Dipole: The Most Recent Measurement And Some History

Cited by in corpus (128)

• Challenges for $\Lambda$CDM: An update
• Science with ASKAP - the Australian Square Kilometre Array Pathfinder
• SkyMapper Southern Survey: First Data Release (DR1)
• CMB Anomalies after Planck
• Cosmology with Phase 1 of the Square Kilometre Array; Red Book 2018: Technical specifications and performance forecasts
• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• A Test of the Cosmological Principle with Quasars
• Detecting a gravitational-wave background with next-generation space interferometers
• Is the Observable Universe Consistent with the Cosmological Principle?
• Planck 2013 results. XXVII. Doppler boosting of the CMB: Eppur si muove
• The WiggleZ Dark Energy Survey: the transition to large-scale cosmic homogeneity
• Probing cosmic isotropy with a new X-ray galaxy cluster sample through the $L_{\text{X}}-T$ scaling relation
• Does Hubble Tension Signal a Breakdown in FLRW Cosmology?
• Cosmic radio dipole from NVSS and WENSS
• Large peculiar motion of the solar system from the dipole anisotropy in sky brightness due to distant radio sources
• A Challenge to the Standard Cosmological Model
• Dipoles in the Sky
• High redshift radio galaxies and divergence from the CMB dipole
• Probing the Cosmological Principle in the counts of radio galaxies at different frequencies
• Revisiting the NVSS number count dipole
• Hints of FLRW Breakdown from Supernovae
• The Cosmic Radio Dipole: Estimators and Frequency Dependence
• On Larger $H_0$ Values in the CMB Dipole Direction
• Dipole anisotropy in sky brightness and source count distribution in radio NVSS data
• Anomalies in Physical Cosmology
• The Local Hole revealed by galaxy counts and redshifts
• Exploring cosmic homogeneity with the BOSS DR12 galaxy sample
• Hubble flow variance and the cosmic rest frame
• Extragalactic Radio Continuum Surveys and the Transformation of Radio Astronomy
• The angular power spectrum of NVSS radio galaxies
• The Signature of Proper Motion in the Microwave Sky
• Testing the Cosmological Principle with CatWISE Quasars: A Bayesian Analysis of the Number-Count Dipole
• Cosmological Measurements with Forthcoming Radio Continuum Surveys
• Dipole Anisotropy in Integrated Linearly Polarized Flux Density in NVSS Data
• Euclid preparation: XIX. Impact of magnification on photometric galaxy clustering
• The velocity field of 2MRS Ks=11.75 galaxies: constraints on beta and bulk flow from the luminosity function
• A new way to test the Cosmological Principle: measuring our peculiar velocity and the large scale anisotropy independently
• Detecting the Cosmic Dipole Anisotropy in Large-Scale Radio Surveys
• The Clustering Dipole of the Local Universe from the Two Micron All Sky Survey
• Dipolar modulation in number counts of WISE-2MASS sources
• Inference of the cosmic rest-frame from supernovae Ia
• Searching for a dipole modulation in the large-scale structure of the Universe
• Clusters of galaxies in the microwave band: influence of the motion of the Solar System
• A large disparity in cosmic reference frames determined from the sky distributions of radio sources and the microwave background radiation
• A dipole anisotropy of galaxy distribution: Does the CMB rest-frame exist in the local universe?
• The cosmic radio dipole: Bayesian estimators on new and old radio surveys
• The clustering of radio galaxies: biasing and evolution versus stellar mass
• Anisotropy of the galaxy cluster X-ray luminosity-temperature relation
• Cosmic homogeneity: a spectroscopic and model-independent measurement
• Impact of local structure on the cosmic radio dipole
• Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
• Large angular scale multipoles at redshift ~0.8
• Searching for anisotropy in the distribution of binary black hole mergers
• Testing the standard model of cosmology with the SKA: the cosmic radio dipole
• The dipole anisotropy of AllWISE galaxies
• Probing cosmological isotropy with Planck Sunyaev-Zeldovich galaxy clusters
• Is there evidence for anomalous dipole anisotropy in the large-scale structure?
• Theoretical systematics in testing the Cosmological Principle with the kinematic quasar dipole
• The scale of homogeneity in the local Universe with the ALFALFA catalogue
• The angular scale of homogeneity in the Local Universe with the SDSS blue galaxies
• Testing homogeneity in the Sloan Digital Sky Survey Data Release Twelve with Shannon entropy
• Cosmic Background dipole measurements with Planck-High Frequency Instrument
• Bayesian estimation of our local motion from the Planck-2018 CMB temperature map
• Detected fluctuations in SDSS LRG magnitudes: Bulk flow signature or systematic?
• On the perturbation of the luminosity distance by peculiar motions
• Testing isotropy in the Universe using photometric and spectroscopic data from the SDSS
• A method for testing the cosmic homogeneity with Shannon entropy
• The Cosmic Dipole in the Quaia Sample of Quasars: A Bayesian Analysis
• Peculiar motion of the solar system derived from a dipole anisotropy in the redshift distribution of distant quasars
• The angular two-point correlation of NVSS galaxies revisited
• Probing statistical isotropy of cosmological radio sources using SKA
• The expected kinematic matter dipole is robust against source evolution
• Testing the Cosmological Principle in the radio sky
• Kinematic dipole detection with galaxy surveys: forecasts and requirements
• An information theory based search for homogeneity on the largest accessible scale
• The dipole anisotropy of WISE x SuperCOSMOS number counts
• Probing large scale homogeneity and periodicity in the LRG distribution using Shannon entropy
• Generalisation of the Kaiser Rocket effect in general relativity in the wide-angle galaxy 2-point correlation function
• Generating Intrinsic Dipole Anisotropy in the Large Scale Structures
• Explaining Excess Dipole in NVSS Data Using Superhorizon Perturbation
• A new method for testing isotropy with Shannon entropy
• Measuring our velocity from fluctuations in number counts
• The galaxy power spectrum from TGSS ADR1 and the effect of flux calibration systematics
• Testing isotropy in the Two Micron All-Sky redshift survey with information entropy
• Reassessment of the dipole in the distribution of quasars on the sky
• Tomographic redshift dipole: Testing the cosmological principle
• Galaxy power spectrum and biasing results from the LOFAR Two-metre Sky Survey (first data release)
• A cross-correlation analysis of CMB lensing and radio galaxy maps
• The kinematic contribution to the cosmic number count dipole
• Testing the isotropy of the log N - log S slope for the NVSS radio catalogue
• A measurement of the Integrated Sachs-Wolfe Effect with the Rapid ASKAP Continuum Survey
• A study of Dipolar Signal in distant Quasars with various observables
• Multipole vectors of completely random microwave skies for $l\le 50$
• Testing the Cosmological Principle: On the Time Dilation of Distant Sources
• Resolution of the incongruency of dipole asymmetries within various large radio surveys -- implications for the Cosmological Principle
• Cosmic dipole tensions: confronting the cosmic microwave background with infrared and radio populations of cosmological sources
• The maximum extent of the filaments and sheets in the cosmic web: an analysis of the SDSS DR17
• The MeerKAT Absorption Line Survey: Homogeneous continuum catalogues towards a measurement of the cosmic radio dipole
• All-sky angular power spectra from cleaned WISE$\times$SuperCOSMOS galaxy number counts
• An Independent Measure of the Kinematic Dipole from SDSS
• Forty years of the Ellis-Baldwin test
• Testing homogeneity of the galaxy distribution in the SDSS using Renyi entropy
• Probing the Cosmological Principle with the CSST Photometric Survey
• A Search for Rapidly Spinning Pulsars and Fast Transients in Unidentified Radio Sources with the NRAO 43-Meter Telescope
• Dipole Anisotropy in Gravitational Wave Source Distribution
• Clustering properties of the CatWISE2020 quasar catalogue and their impact on the cosmic dipole anomaly
• Gravitational Lensing from a Spacetime Perspective
• Redshift drift in a universe with structure III: Numerical relativity
• Measuring our peculiar velocity from spectroscopic redshift surveys
• Rotation of the polarization vector from distant radio galaxies in the perturbed FRW metric
• Matter Dipole and Hubble Tension due to Large Wavelength Perturbations
• Can anisotropy in the galaxy distribution tell the bias?
• Probing Cosmology beyond $\Lambda$CDM using the SKA
• Linear Relativistic Corrections in the Spherical Fourier-Bessel Power Spectrum
• The Universe is Brighter in the Direction of Our Motion: Galaxy Counts and Fluxes are Consistent with the CMB Dipole
• Exploring the cosmic microwave background dipole direction using gamma-ray bursts
• The kinematic cosmic dipole beyond Ellis and Baldwin
• Solar peculiar motion inferred from dipole anisotropy in redshift distribution of quasars appears to lie along the Galactic Centre direction
• Numerical evolution of Maxwell's equations for wavefronts propagating through a spherical gravitational potential
• Cosmic Dipoles from Large-Scale Structure Surveys
• The Kaiser-Rocket effect: three decades and counting
• The Ellis and Baldwin test of the Cosmic Dipole: Exploring the impact of multiple flux density cuts
• Testing the cosmological principle with quasars
• Probing dipole and quadrupole anisotropy in Gamma-ray bursts from Swift dataset
• The Cosmological Dipole in Tilted Anisotropic Universes
• Galaxy number-count dipole and superhorizon fluctuations
• Detector induced anisotropies on the angular distribution of gravitational wave sources and opportunities of constraining horizon scale anisotropies
• Clustering properties of TGSS radio sources