Clusters of galaxies

Rood, Herbert J.

doi:10.1088/0034-4885/44/10/002

Cited by 16 publications

(9 citation statements)

References 214 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Faber & Gallagher 1979;Binggeli et al 1988;Giovanelli & Haynes 1991;Koo & Kron 1992;Ellis 1997), clusters of galaxies (e.g. Bahcall 1977;Rood 1981;Forman & Jones 1982;Bahcall 1988;Sarazin 1986), and active galactic nuclei (e.g. Rees 1984;Weedman 1986;Blandford et al 1990;Hartwick & Schade 1990;Warren & Hewett 1990;Antonucci 1993;Peterson 1997).…”

Section: Relevant Properties Of Lenses and Sourcesmentioning

confidence: 99%

Weak Gravitational Lensing

Schneider

2006

Saas-Fee Advanced Courses

131

View full text Add to dashboard Cite

We review theory and applications of weak gravitational lensing. After summarising Friedmann-Lemaître cosmological models, we present the formalism of gravitational lensing and light propagation in arbitrary space-times. We discuss how weak-lensing effects can be measured. The formalism is then applied to reconstructions of galaxy-cluster mass distributions, gravitational lensing by large-scale matter distributions, QSO-galaxy correlations induced by weak lensing, lensing of galaxies by galaxies, and weak lensing of the cosmic microwave background.

show abstract

Section: Relevant Properties Of Lenses and Sourcesmentioning

confidence: 99%

Weak Gravitational Lensing

Schneider

2006

Saas-Fee Advanced Courses

131

View full text Add to dashboard Cite

show abstract

“…I begin with some qualitative considerations of the void phenomenon. Rood (1981) gives an excellent picture of the state of observational studies of galaxy clustering two decades ago. He remarks that 20 years earlier Mayall (1960, Fig. 3) had found that in the direction of the Coma Cluster, far more galaxies were in the cluster than the foreground.…”

Section: Introductionmentioning

confidence: 99%

The Void Phenomenon

Peebles

2001

ApJ

316

362

View full text Add to dashboard Cite

Advances in theoretical ideas on how galaxies formed have not been strongly inÑuenced by the advances in observations of what might be in the voids between the concentrations of ordinary optically selected galaxies. The theory and observations are maturing, and the search for a reconciliation o †ers a promising opportunity to improve our understanding of cosmic evolution. I comment on the development of this situation and present an update of a nearest neighbor measure of the void phenomenon that may be of use in evaluating theories of galaxy formation.

show abstract

“…For years, mass estimation of groups and clusters of galaxies has been one of the classical tasks of astronomers (see, for example : Zwicky 1933;Rood et al 1970;Gott & Turner 1977;Rood & Dickel 1978;Rood 1981;Huchra & Geller 1982;Geller 1984;Karachentsev 2005). Galactic kinematics, observations of X-rays from hot intra-cluster gas or gravitational lensing are some of the techniques used to infer the mass of these systems.…”

Section: Introductionmentioning

confidence: 99%

Surface term effects on mass estimators

Membrado

Pacheco

2016

A&A

View full text Add to dashboard Cite

Context. We propose a way of estimating the mass contained in the volume occupied by a sample of galaxies in a virialized system. Aims. We analyze the influence of surface effects and the contribution of the cosmological constant terms on our mass estimations of galaxy systems. Methods. We propose two equations that contain surface terms to estimate galaxy sample masses. When the surface terms are neglected, these equations provide the so-called virial and projected masses. Both equations lead to a single equation that allows sample masses to be estimated without the need for calculating surface terms. Sample masses for some nearest galaxy groups are estimated and compared with virialized masses determined from turn-around radii and results of a spherical infall model. Results. Surface effects have a considerable effect on the mass estimations of the studied galaxy groups. According to our results, they lead sample masses of some groups to being less than half the virial mass estimations and even less than 10% of projected mass estimations. However, the contributions of cosmological constant terms to mass estimations are smaller than 2% for the majority of the virialized groups studied. Our estimations are in agreement with virialized masses calculated from turn-around radii. Virialized masses for complexes were found to be: (8.9 ± 2.8) × 10 11 M for the Milky Way -M 31; (12.5 ± 2.5) × 10 11 M for M 81 -NGC 2403; (21.5 ± 7.7) × 10 11 M . for Cantaurs A -M 83; and (7.9 ± 2.6) × 10 11 M . for IC 324 -Maffei. Conclusions. The nearest galaxy groups located inside a sphere of 5 Mpc have been addressed to explore the performance of our mass estimator. We have seen that surface effects make mass estimations of galaxy groups rather smaller than both virial and projected masses. In mass calculations, cosmological constant terms can be neglected; nevertheless, the collapse of cold dark matter leading to virialized structures is strongly affected by the cosmological constant. We have also seen that, if mass density were proportional to luminosity density on different scales in the Universe, the 5 Mpc sphere would have a mean density close to that of the sphere region containing galaxies and systems of galaxies; thus, the rest of the sphere could contain regions of low-mass dark halos with similar mass density. This mass density would be about 4.5 times greater than that of the matter background of the Universe at present.

show abstract

Clusters of galaxies

Cited by 16 publications

References 214 publications

Weak Gravitational Lensing

Weak Gravitational Lensing

The Void Phenomenon

Surface term effects on mass estimators

Contact Info

Product

Resources

About