The Peculiar Velocity of the Local Group in the Direction of the Virgo Cluster

1987 ◽  
pp. 115-115
Author(s):  
L. Staveley-Smith ◽  
R. D. Davies
Keyword(s):  
Local Group ◽  
Virgo Cluster ◽  
Peculiar Velocity

scholarly journals The Peculiar Velocity of the Local Group in the Direction of the Virgo Cluster

1987 ◽  
Vol 117 ◽  
pp. 115-115
Author(s):  
L. Staveley-Smith ◽  
R. D. Davies
Keyword(s):  
Local Group ◽  
Hubble Constant ◽  
Virgo Cluster ◽  
Density Parameter ◽  
Field Observations ◽  
Peculiar Velocity ◽  
Peculiar Velocities ◽  
Scaling Methods ◽  
Crucial Test ◽  
Local Value

The measurement of the amplitude of the Local Group infall velocity towards the Virgo Cluster is a crucial test for the value of the universal density parameter Ωo and the ratio of the universal Hubble constant to its local value. However, a very large discrepancy exists between total infall velocities derived from peculiar velocity field observations and those derived from “scaling” methods using standard candles in the Virgo and Coma clusters. The former have tended to produce high Virgocentric peculiar velocities (350 to 500 km s−1) whilst the latter give much lower values (-70 to 100 km s−1).

scholarly journals The Distance of the Virgo Cluster

1983 ◽  
Vol 6 ◽  
pp. 227-239
Author(s):  
David A. Hanes
Keyword(s):  
Cosmic Microwave Background ◽  
Velocity Component ◽  
Local Group ◽  
Virgo Cluster ◽  
Microwave Background ◽  
Global Expansion ◽  
Peculiar Velocity ◽  
Rosetta Stone ◽  
Extragalactic Distance Scale ◽  
Simple Picture

Until the discovery (Corey & Wilkinson, 1976) of the anisotropy of the cosmic microwave background, the Virgo cluster represented something like a Rosetta Stone for many observational cosmologists: in the absence of a significant peculiar velocity component for the Local Group in the direction of the Virgo cluster, its distance, accurately measured, might reveal the global expansion rate and the Hubble age. Although this simple picture has changed, the distance of the Virgo cluster remains important, partly for a sharper understanding of the properties of rich clusters and the galaxies they contain, but more importantly (for my purposes here) as an interesting distance over which we may test various constructions of the extragalactic distance scale.

scholarly journals THE NEXT GENERATION VIRGO CLUSTER SURVEY. VII. THE INTRINSIC SHAPES OF LOW-LUMINOSITY GALAXIES IN THE CORE OF THE VIRGO CLUSTER, AND A COMPARISON WITH THE LOCAL GROUP

2016 ◽  
Vol 820 (1) ◽  
pp. 69 ◽  
Author(s):  
Rubén Sánchez-Janssen ◽  
Laura Ferrarese ◽  
Lauren A. MacArthur ◽  
Patrick Côté ◽  
John P. Blakeslee ◽  
...  
Keyword(s):  
Local Group ◽  
Virgo Cluster ◽  
Next Generation ◽  
Cluster Survey ◽  
The Core

scholarly journals Large-Scale Anisotropy at Centimeter Wavelengths

1983 ◽  
Vol 104 ◽  
pp. 143-148
Author(s):  
David T. Wilkinson
Keyword(s):  
Early Universe ◽  
Large Scale ◽  
Local Group ◽  
Virgo Cluster ◽  
Scientific Interest ◽  
Physical Processes ◽  
General Direction ◽  
Systematic Effects ◽  
Better Than

Scientific interest in large-scale anisotropy measurements is now focused on intrinsic effects, which could tell us much about the early Universe. Current experimental precision of better than 10−4 K begins to probe for interesting physical processes. However, at these levels of precision systematic effects and foreground sources present serious difficulties. Some recent results from balloon flights of a maser radiometer (λ 1.2 cm) and a cooled mixer (λ 3 mm) are discussed and interpreted. The dipole effect gives a velocity for the Local Group in the general direction of the Virgo cluster. The Earth's motion is clearly seen. There is no quadrupole detected at a level of ΔT/T ∼ 5 × 10−5.

scholarly journals Correcting for peculiar velocities of Type Ia supernovae in clusters of galaxies

2018 ◽  
Vol 615 ◽  
pp. A162 ◽  
Author(s):  
P.-F. Léget ◽  
M. V. Pruzhinskaya ◽  
A. Ciulli ◽  
E. Gangler ◽  
G. Aldering ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Virgo Cluster ◽  
Type Ia Supernovae ◽  
Hubble Diagram ◽  
Cosmological Redshift ◽  
Peculiar Velocity ◽  
Peculiar Velocities ◽  
Velocity Correction ◽  
Type Ia ◽  
Ia Supernovae

Context. Type Ia supernovae (SNe Ia) are widely used to measure the expansion of the Universe. To perform such measurements the luminosity and cosmological redshift (z) of the SNe Ia have to be determined. The uncertainty on z includes an unknown peculiar velocity, which can be very large for SNe Ia in the virialized cores of massive clusters. Aims. We determine which SNe Ia exploded in galaxy clusters using 145 SNe Ia from the Nearby Supernova Factory. We then study how the correction for peculiar velocities of host galaxies inside the clusters improves the Hubble residuals. Methods. We found 11 candidates for membership in clusters. We applied the biweight technique to estimate the redshift of a cluster. Then, we used the galaxy cluster redshift instead of the host galaxy redshift to construct the Hubble diagram. Results. For SNe Ia inside galaxy clusters, the dispersion around the Hubble diagram when peculiar velocities are taken into account is smaller compared with a case without peculiar velocity correction, which has a wRMS = 0.130 ± 0.038 mag instead of wRMS = 0.137 ± 0.036 mag. The significance of this improvement is 3.58σ. If we remove the very nearby Virgo cluster member SN2006X (z < 0.01) from the analysis, the significance decreases to 1.34σ. The peculiar velocity correction is found to be highest for the SNe Ia hosted by blue spiral galaxies. Those SNe Ia have high local specific star formation rates and smaller stellar masses, which is seemingly counter to what might be expected given the heavy concentration of old, massive elliptical galaxies in clusters. Conclusions. As expected, the Hubble residuals of SNe Ia associated with massive galaxy clusters improve when the cluster redshift is taken as the cosmological redshift of the supernova. This fact has to be taken into account in future cosmological analyses in order to achieve higher accuracy for cosmological redshift measurements. We provide an approach to do so.

scholarly journals The Local Supercluster

1978 ◽  
Vol 79 ◽  
pp. 205-213 ◽  
Author(s):  
G. de Vaucouleurs
Keyword(s):  
Small Groups ◽  
Large Scale ◽  
Local Group ◽  
Virgo Cluster ◽  
General Phenomenon ◽  
Quantitative Evidence ◽  
Present Concept ◽  
Local Supercluster ◽  
Density Excess

The first quantitative evidence for a large scale density excess or “metagalactic cloud” including the Local Group was obtained by Holmberg (1937) and confirmed by Reiz (1941). the present concept of the Local Supercluster (LSC) as a flattened aggregate of field galaxies, small groups and larger clouds centered at the Virgo cluster was formulated 25 years ago (de Vaucouleurs 1953) even before large-scale superclustering was recognized as a general phenomenon. See review papers in Vistas in Astronomy (1956), Soviet Astronomy (1960), Science (1970), Publ. Astron. Soc. Pacific (1971), and IAU Symp. No. 63 (Abell 1974).

scholarly journals Spiral Galaxies and the Peculiar Velocity Field

1996 ◽  
Vol 168 ◽  
pp. 183-191 ◽  
Author(s):  
Riccardo Giovanelli ◽  
Martha P. Haynes ◽  
Pierre Chamaraux ◽  
Luiz N. Da Costa ◽  
Wolfram Freudling ◽  
...  
Keyword(s):  
Velocity Field ◽  
Reference Frame ◽  
Large Scale ◽  
Local Group ◽  
Spiral Galaxies ◽  
Density Parameter ◽  
Compelling Evidence ◽  
Homogeneous Sample ◽  
Peculiar Velocity ◽  
Peculiar Velocities

We report results of a redshift-independent distance measurement survey that extends to all sky and out to a redshift of approximately 7500 km s−1. Tully–Fisher (TF) distances for a homogeneous sample of 1600 late spiral galaxies are used to analyze the peculiar velocity field. We find large peculiar velocities in the neighborhood of superclusters, such as Perseus–Pisces (PP) and Hydra–Centaurus, but the main clusters embedded in those regions appear to be virtually at rest in the CMB reference frame. We find no compelling evidence for large-scale bulk flows, whereby the Local Group, Hydra–Cen and PP would share a motion of several hundred km s−1with respect to the CMB. Denser sampling in the PP region allows a clear detection of infall and backflow motions, which can be used to map the mass distribution in the supercluster and to obtain an estimate of the cosmological density parameter.

scholarly journals Two-body problem in presence of cosmological constant

2019 ◽  
Vol 28 (12) ◽  
pp. 1950155
Author(s):  
G. S. Bisnovatyi-Kogan ◽  
M. Merafina
Keyword(s):  
Angular Momentum ◽  
Cosmological Constant ◽  
Body Problem ◽  
Local Group ◽  
Classical Case ◽  
Virgo Cluster ◽  
Body Motion ◽  
Critical Parameters ◽  
Two Body Problem ◽  
Qualitative Picture

We consider the Kepler two-body problem in presence of the cosmological constant [Formula: see text]. Contrary to the classical case, where finite solutions exist for any angular momentum of the system [Formula: see text], in presence of [Formula: see text] finite solutions exist only in the interval [Formula: see text]. The qualitative picture of the two-body motion is described, and critical parameters of the problem are found. Application is made to the relative motion of the Local Group and Virgo cluster.

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