On the microwave background anisotropy produced by Great Attractor-like structures

Fullana, M. J.; Sáez, D.; Arnau, J. V.

doi:10.1086/192070

Cited by 14 publications

(15 citation statements)

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“…The SSC is a non‐linear structure, and the amplitude of the induced anisotropies cannot be reliably calculated in linear perturbation theory. According to a comparison of linear and exact calculations for GA‐like objects with the LTB model in Fullana et al (1994), linear theory is reliable at distances comparable to the Hubble scale, but fails for structures within 1000 h −1 Mpc or so.…”

Section: Discussionmentioning

confidence: 99%

The microwave sky and the local Rees—Sciama effect

Rakić

Räsänen

Schwarz

2006

Monthly Notices of the Royal Astronomical Society: Letters

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The microwave sky shows unexpected features at the largest angular scales, among them the alignments of the dipole, quadrupole and octopole. Motivated by recent X-ray cluster studies, we investigate the possibility that local structures at the 100 h −1 Mpc scale could be responsible for such correlations. These structures give rise to a local Rees-Sciama contribution to the microwave sky that may amount to T /T ∼ 10 −5 at the largest angular scales. We model local structures by a spherical overdensity (Lemaître-Tolman-Bondi model) and assume that the Local Group is falling toward the centre. We superimpose the local Rees-Sciama effect on a statistically isotropic, Gaussian sky. As expected, we find alignments among low multipoles, but a closer look reveals that they do not agree with the type of correlations revealed by the data.

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Section: Discussionmentioning

confidence: 99%

The microwave sky and the local Rees—Sciama effect

Rakić

Räsänen

Schwarz

2006

Monthly Notices of the Royal Astronomical Society: Letters

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“…where E αβ is the electric part of the Weyl tensor (16) and H = (1/3)θ is the Hubble parameter (15). As can be seen, in some regions W 2 1.…”

Section: Arrangement Of the Swiss Cheese Modelmentioning

confidence: 90%

“…Therefore, there is a need for application of exact and inhomogeneous models to the study of the light propagation and its impact on the CMB temperature fluctuations. This issue has been extensively studied within spherically symmetric models-within the thin shell approximation [8][9][10] and within the Lemaître-Tolman model [11][12][13][14][15][16][17]. However, most of the cosmic structures are not spherically symmetric, and thus the study of light propagation in non-spherical models is essential.…”

Section: Introductionmentioning

confidence: 99%

The Szekeres Swiss Cheese model and the CMB observations

Bolejko

2009

Gen Relativ Gravit

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This paper presents the application of the Szekeres Swiss Cheese model to the analysis of observations of the cosmic microwave background (CMB) radiation. The impact of inhomogeneous matter distribution on the CMB observations is in most cases studied within the linear perturbations of the Friedmann model. However, since the density contrast and the Weyl curvature within the cosmic structures are large, this issue is worth studying using another approach. The Szekeres model is an inhomogeneous, non-symmetrical and exact solution of the Einstein equations. In this model, light propagation and matter evolution can be exactly calculated, without such approximations as small amplitude of the density contrast. This allows to examine in more realistic manner the contribution of the light propagation effect to the measured CMB temperature fluctuations. The results of such analysis show that small-scale, non-linear inhomogeneities induce, via Rees-Sciama effect, temperature fluctuations of amplitude $10^{-7} - 10^{-5}$ on angular scale $\theta< 0.24^{\circ}$ ($\ell > 750$). This is still much smaller than the measured temperature fluctuations on this angular scale.However, local and uncompensated inhomogeneities can induce temperature fluctuations of amplitude as large as $10^{-3}$, and thus can be responsible the low multipoles anomalies observed in the angular CMB power spectrum.Comment: 18 pages, 6 figures; new models added; discussion of the Weyl curvature added; improved description of model

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“…The most popular method has been the linearized approach (), allowing the modelling of arbitrarily shaped inhomogeneities (Martínez‐González & Sanz 1990; Martínez‐González et al 1990; Chodorowski 1991). This method has been particularly used for Great Attractor‐like structures located at redshifts as high as z =5.9, where less strong non‐linear effects are expected (Sáez, Arnau & Fullana 1993, 1995; Arnau, Fullana & Sáez 1994; Fullana, Sáez & Arnau 1994).…”

Section: Secondary Gravitational Effectmentioning

confidence: 99%

Microwave background anisotropies arising from non-linear structures in open and Λ universes

Dabrowski¹,

Hall²,

Sawicki³

et al. 2000

Monthly Notices of the Royal Astronomical Society

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A new method arising from a gauge-theoretic approach to general relativity is applied to the formation of clusters in an expanding universe. The three cosmological models (Ω 0 =1, Ω Λ =0), (Ω 0 =0.3, Ω Λ =0.7), (Ω 0 =0.3, Ω Λ =0) are considered, which extends our previous application . A simple initial velocity and density perturbation of finite extent is imposed at the epoch z = 1000 and we investigate the subsequent evolution of the density and velocity fields for clusters observed at redshifts z = 1, z = 2 and z = 3. Photon geodesics and redshifts are also calculated so that the Cosmic Microwave Background (CMB) anisotropies due to collapsing clusters can be estimated. We find that the central CMB temperature decrement is slightly stronger and extends to larger angular scales in the non-zero Ω Λ case. This effect is strongly enhanced in the open case. Gravitational lensing effects are also considered and we apply our model to the reported microwave decrement observed towards the quasar pair PC 1643+4631 A&B.Key words: Gravitation -cosmology: theory -cosmology: gravitational lensingcosmic microwave background -quasars: individual: PC1643+4631 A&B -galaxies: clustering SECONDARY GRAVITATIONAL EFFECTRees and Sciama (1968) suggested that the presence of an evolving structure on the line of sight of a Cosmic Microwave Background (CMB) photon could significantly affect its observed temperature. This secondary gravitational effect is often described in terms of the potential well experienced by the CMB photon. For example, the potential well of a collapsing cluster becomes deeper over time so that the CMB photon has to climb out of a well deeper than that into which it fell, suffering a net loss of energy. As suggested in Rees and Sciama (1968) there is however a competing effect due to the extra time delay encountered by the photon. The overall effect can therefore be of either sign. The photon accumulates a redshift along its geodesic, resulting in a net temperature perturbation. In the weak-field approximation we have (see Martínez-González, Sanz & Silk 1990) where Φ is the gravitational potential of the perturbation and t is the cosmic time. A rough estimate of an upper limit to this effect can be estimated by assuming that the potential well varies from Φ = 0 to Φ = Φc during the time ⋆ Email: youri@mrao.cam.ac.uk that the photon traverses it, where Φc is the gravitational potential of a rich Abell cluster. In this case, we haveThe potential of the cluster can be related to the velocity dispersion σ through σ 2 = GM/R = Φc, where M and R are the mass and radius of the cluster. Assuming σ = 1000 km s −1 givesIn most cases, this anisotropy should therefore be small compared with other secondary anisotropies caused by the interaction of CMB photons with non-linear structures, such as the thermal Sunyaev-Zel'dovich (SZ) effect. However, equation (1) is only valid in the linear regime and a fully relativistic treatment in the non-linear regime is necessary to estimate accurately the Rees-Sciama effect. Seve...

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On the microwave background anisotropy produced by Great Attractor-like structures

Cited by 14 publications

References 0 publications

The microwave sky and the local Rees—Sciama effect

The microwave sky and the local Rees—Sciama effect

The Szekeres Swiss Cheese model and the CMB observations

Microwave background anisotropies arising from non-linear structures in open and Λ universes

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