On The Origin of the Local Group's Peculiar Velocity

Abstract

We aim to settle the debate regarding the fraction of the Local Group's peculiar velocity that is induced by structures beyond the Great Attractor by calculating the dipole anisotropy of the largest, all-sky, truly X-ray selected cluster sample compiled to date. The sample is the combination of the REFLEX catalog in the southern hemisphere, the eBCS sample in the north, and the CIZA survey in the Galactic plane. The composite REFLEX+eBCS+CIZA sample overcomes many of the problems inherent to previous galaxy and cluster catalogs which limited their effectiveness in determining the origin of the Local Group's motion. From the dipole anisotropy present in the cluster distribution we determine that 44% of the Local Group's peculiar velocity is due to infall into the GA region, while 56% is in the form of a large-scale flow induced by more distant overdensities between 130 and 180 h^-1 Mpc away. In agreement with previous analyses, we find that the Shapley supercluster is the single overdensity most responsible for the increase in the dipole amplitude beyond 130 h^-1 Mpc, generating 30.4% of the large-scale contribution. We find that numerous groupings and loose associations of clusters at roughly the same distance as the Shapley region induce a significant acceleration on the Local Group. These include the well known Horologium-Reticulum concentration, as well as newly noted associations centered on Abell 3667 and Abell 3391 and a string of CIZA clusters near C1410 which may trace an extension of the Shapley complex into the Zone of Avoidance. We also note that the large-scale anisotropy measured in the cluster distribution near 150 h^-1 Mpc may be due to an observed underdensity of clusters in the northern hemisphere near this distance. (abridged)

arXiv comment12 pages, 10 figures (2 color), Accepted for publication in ApJ; minor revisions, one figure added

References in corpus (29)

• The ROSAT Brightest Cluster Sample (BCS) - I. The compilation of the sample and the cluster log N-log S distribution
• The ROSAT-ESO Flux Limited X-ray (REFLEX) Galaxy Cluster Survey. V. The cluster catalogue
• The Northern ROSAT All-Sky (NORAS) Galaxy Cluster Survey I: X-ray Properties of Clusters Detected as Extended X-ray Sources
• Properties of the X-ray brightest Abell-type clusters of galaxies (XBACs) from ROSAT All-Sky Survey data --- I. The sample
• Dipole Anisotropy in the COBE DMR First-Year Sky Maps
• The ROSAT Brightest Cluster Sample (BCS) - IV. The extended sample
• The SBF Survey of Galaxy Distances. II. Local and Large-Scale Flows
• The ROSAT-ESO Flux Limited X-Ray (REFLEX) Galaxy Cluster Survey I: The Construction of the Cluster Sample
• The Supercluster-Void Network I. The Supercluster Catalogue and Large-Scale Distribution
• Cosmological constraints from the local X-ray luminosity function of the most X-ray luminous galaxy clusters
• Physics of the Merging Clusters Cygnus A, A3667, and A2065
• The Dipole Anisotropy of the 2 Micron All-Sky Redshift Survey
• Wiener Reconstruction of Large-Scale Structure from Peculiar Velocities
• The peculiar motions of early-type galaxies in two distant regions - VII. Peculiar velocities and bulk motions
• A Large-Scale Bulk Flow of Galaxy Clusters
• Projection effects in cluster catalogues
• Redshift-distance Survey of Early-type Galaxies: the ENEARc Cluster Sample
• The IRAS PSCz Dipole
• The LCO/Palomar 10,000 km/sec Cluster Survey. II. Constraints on Large-Scale Streaming
• Seeking the Local Convergence Depth. The Abell Cluster Dipole Flow to 200 Mpc/h
• On density and velocity fields and beta from the IRAS PSCz survey
• No Hubble Bubble in the Local Universe
• Likelihood Analysis of the Local Group Acceleration
• The X-ray Cluster Dipole
• The Dipole Anisotropy of the First All-Sky X-ray Cluster Sample
• Reconstructing Positions and Peculiar Velocities of Galaxy Clusters within 20000 km/sec. I: The Cluster 3D Dipole
• The Empirical X-Ray Luminosity - Gravitational Mass Relation for Clusters of Galaxies
• The Cluster Distribution as a Test for Dark Matter Models. II: The Dipole Structure
• Large-Scale Coherent Dipole Anisotropy ?

Cited by in corpus (67)

• Cosmology and Fundamental Physics with the Euclid Satellite
• Cosmology and fundamental physics with the Euclid satellite
• Our Peculiar Motion Away from the Local Void
• A measurement of large-scale peculiar velocities of clusters of galaxies: results and cosmological implications
• The 2M++ galaxy redshift catalogue
• 2MASS Photometric Redshift catalog: a comprehensive three-dimensional census of the whole sky
• A new measurement of the bulk flow of X-ray luminous clusters of galaxies
• INTEGRAL/IBIS all-sky survey in hard X-rays
• Cosmic flow from 2MASS redshift survey: The origin of CMB dipole and implications for LCDM cosmology
• Mapping Large-Scale Structures Behind the Galactic Plane: The Second CIZA Subsample
• The supernova Hubble diagram for off-center observers in a spherically symmetric inhomogeneous universe
• Light propagation in statistically homogeneous and isotropic universes with general matter content
• Measuring cosmic bulk flows with Type Ia Supernovae from the Nearby Supernova Factory
• 3D Velocity and Density Reconstructions of the Local Universe with Cosmicflows-1
• The 6dF Galaxy Survey: Bulk Flows on $50-70h^{-1}$ Mpc scales
• The Dipole Repeller
• Evaluating backreaction with the peak model of structure formation
• A measurement of large-scale peculiar velocities of clusters of galaxies: technical details
• Constraining $f(R)$ gravity by the Large Scale Structure
• Hubble flow variance and the cosmic rest frame
• How unusual are the Shapley Supercluster and the Sloan Great Wall?
• Measuring the dark flow with public X-ray cluster data
• The Norma Cluster (ACO 3627): I. A Dynamical Analysis of the Most Massive Cluster in the Great Attractor
• Discovery of a supercluster in the ZOA in Vela
• Future Evolution of Bound Superclusters in an Accelerating Universe
• Measurement of the electron-pressure profile of galaxy clusters in Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data
• Is the 2MASS clustering dipole convergent?
• First measurement of the bulk flow of nearby galaxies using the cosmic microwave background
• The growth rate of cosmic structures in the local Universe with the ALFALFA survey
• A dipole anisotropy of galaxy distribution: Does the CMB rest-frame exist in the local universe?
• The WSRT ZoA Perseus-Pisces Filament wide-field HI imaging survey I. HI catalogue and atlas
• Constraining the redshift evolution of the Cosmic Microwave Background black-body temperature with PLANCK data
• The multipole expansion of the local expansion rate
• On the recovery of Local Group motion from galaxy redshift surveys
• Constraining spatial variations of the fine structure constant using clusters of galaxies and Planck data
• "Dark energy" in the Local Void
• The Linearity of the Cosmic Expansion Field from 300 to 30,000 km/s and the Bulk Motion of the Local Supercluster with Respect to the CMB
• Measuring the redshift dependence of the CMB monopole temperature with PLANCK data
• The error budget of the Dark Flow measurement
• The Nancay HI Zone of Avoidance survey of 2MASS bright galaxies
• The PSCz Dipole Revisited
• The Density Contrast of the Shapley Supercluster
• The cosmological bulk flow in QCDM model: (In)consistency with $\Lambda CDM$
• Galaxies behind the Galactic plane: First results and perspectives from the VVV Survey
• Predicting Structures in the Zone of Avoidance
• Average luminosity distance in inhomogeneous universes
• The Norma cluster (ACO3627) -- III. The Distance and Peculiar Velocity via the Near-Infrared Ks-band Fundamental Plane
• Probing the rest-frame of the Universe with near-IR cosmic infrared background
• Astrophysics in 2006
• The bulk flow motion and the Hubble-Lema\^ıtre law in the Local Universe with the ALFALFA survey
• Is the misalignment of the Local Group velocity and the 2MASS Redshift Survey dipole typical in a LambdaCDM model?
• Discovery of Two Galaxies Deeply Embedded in the Great Attractor Wall
• Cosmology when living near the Great Attractor
• SZ/X-ray scaling relations using X-ray data and Planck Nominal maps
• Galaxy clusters in the Vela supercluster. -- I. Deep NIR catalogues
• Modelling the WMAP large-angle anomalies as an effect of a local density inhomogeneity
• The Distance and Peculiar Velocity of the Norma cluster (ACO 3627) using the Near-Infrared $J$ and $K_s$-band Fundamental Plane Relations
• Mapping the Cosmic Web with the largest all-sky surveys
• The Polarization Signature of Local Bulk Flows
• Violation of Equivalence Principle in Neutrino Sector: Probing the Extended Parameter Space
• One of Everything: The Breakthrough Listen Exotica Catalog
• The $K_s$-band luminosity function of the rich cluster VC04 in the Vela supercluster
• Can Chameleon fields be the source of both the dark energy dipole and the CMB dipole?
• Probing $f(R)$ gravity with PLANCK data on cluster pressure profiles
• Motion of the Local Group as a cosmological probe
• Constraints on the dark energy dipole from large-scale structures
• The Kaiser-Rocket effect: three decades and counting