The integrated Sachs–Wolfe signal from BOSS superstructures

Granett, B. R.; Kovács, András; Hawken, Adam J.

doi:10.1093/mnras/stv2110

Cited by 35 publications

(43 citation statements)

References 53 publications

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“…Foremost, Granett et al (2008) (Gr08, hereafter) defined a catalog of 50-50 significant super voids and superclusters using SDSS photo-z data. Using a BOSS DR12 spec-z galaxy catalogue, Granett et al (2015) reconstructed the average redshift space shape of the Gr08 super voids that were originally defined by photo-z tracers, finding an axis ratio R /R ⊥ ≈ 2.6 ± 0.4.…”

Section: Sdss Super Voids and Their Isw-like Effectmentioning

confidence: 99%

The part and the whole: voids, supervoids, and their ISW imprint

Kovács

2017

Monthly Notices of the Royal Astronomical Society

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The integrated Sachs-Wolfe imprint of extreme structures in the cosmic web probes the dynamical nature of dark energy. Looking through typical cosmic voids, no anomalous signal has been reported. On the contrary, super voids, associated with large-scale fluctuations in the gravitational potential, have shown potentially disturbing excess signals. In this study, we used the Jubilee ISW simulation to demonstrate how the stacked signal depends on the void definition. We found that large underdensities, with at least ≈ 5 merged sub-voids, show a peculiar ISW imprint shape with central cold spots and surrounding hot rings, offering a natural way to define super voids in the cosmic web. We then inspected the real-world BOSS DR12 data using the simulated imprints as templates. The imprinted profile of BOSS super voids appears to be more compact than in simulations, requiring an extra α ≈ 0.7 re-scaling of filter sizes. The data reveals an excess ISW-like signal with A ISW ≈ 9 amplitude at the ≈ 2.5σ significance level, unlike previous studies that used isolated voids and reported good consistency with A ISW = 1. The tension with the Jubilee-based ΛCDM predictions is > ∼ 2σ, in consistency with independent analyses of super voids in Dark Energy Survey data. We show that such a very large enhancement of the A ISW parameter hints at a possible causal relation between the CMB Cold Spot and the Eridanus super void. The origin of these findings remains unclear.

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Section: Sdss Super Voids and Their Isw-like Effectmentioning

confidence: 99%

The part and the whole: voids, supervoids, and their ISW imprint

Kovács

2017

Monthly Notices of the Royal Astronomical Society

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“…Another common approach in measuring the ISW signal is by stacking of voids and super-clusters. Similar to the cross-correlation method, studies using this approach have obtained detection significances ranging from low to moderate (Granett et al 2015;Kovács et al 2017), to 3σ or higher (Pápai et al 2011;Nadathur & Crittenden 2016;Cai et al 2017;Planck Collaboration et al 2016c). Interestingly, a number of these studies have reported a signal with a higher amplitude than expected based on ΛCDM predictions.…”

Section: Introductionmentioning

confidence: 99%

Cross-correlating Planck with VST ATLAS LRGs: a new test for the ISW effect in the Southern hemisphere

Ansarinejad

Mackenzie

Shanks

et al. 2020

Monthly Notices of the Royal Astronomical Society

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The Integrated Sachs-Wolfe (ISW) effect probes the late-time expansion history of the universe, offering direct constraints on dark energy. Here we present our measurements of the ISW signal at redshifts ofz = 0.35, 0.55 and 0.68, using the cross-correlation of the Planck CMB temperature map with ∼ 0.5 million Luminous Red Galaxies (LRGs) selected from the VST ATLAS survey. We then combine these with previous measurements based on WMAP and similar SDSS LRG samples, providing a total sample of ∼ 2.1 million LRGs covering ∼ 12000 deg 2 of sky. Atz = 0.35 andz = 0.55 we detect the ISW signal at 1.2σ and 2.3σ (or 2.6σ combined), in agreement with the predictions of ΛCDM. We verify these results by repeating the measurements using the BOSS LOWZ and CMASS, spectroscopically confirmed LRG samples. We also detect the ISW effect in three magnitude limited ATLAS+SDSS galaxy samples extending to z ≈ 0.4 at ∼ 2σ per sample. However, we do not detect the ISW signal atz = 0.68 when combining the ATLAS and SDSS results. Further tests using spectroscopically confirmed eBOSS LRGs at this redshift remain inconclusive due to the current low sky coverage of the survey. If the ISW signal is shown to be redshift dependent in a manner inconsistent with the predictions of ΛCDM, it could open the door to alternative theories such as modified gravity. It is therefore important to repeat the high redshift ISW measurement using the completed eBOSS sample, as well as deeper upcoming surveys such as DESI and LSST.

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“…A limitation of G08 is that their voids were found in a photometric redshift catalogue, with large redshift uncertainties compared to spectroscopic redshift samples. But the photometric redshift smearing may even help to detect very elongated structures along the line of sight, which may have the highest ISW signals (Granett, Kovács & Hawken 2015). Our goal in this study is therefore to conduct a similar analysis using the larger SDSS Data Release 12 (DR12) CMASS spectroscopic redshift sample, which covers the same redshift range (0.4 < z < 0.7) and the same volume as that of the DR6 photometric redshift sample in the North Galactic Cap (NGC) region.…”

Section: Introductionmentioning

confidence: 99%

The lensing and temperature imprints of voids on the cosmic microwave background

Cai

Neyrinck

Mao

et al. 2016

Mon. Not. R. Astron. Soc.

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We have searched for the signature of cosmic voids in the CMB, in both the Planck temperature and lensing-convergence maps; voids should give decrements in both. We use ZOBOV voids from the DR12 SDSS CMASS galaxy sample. We base our analysis on N -body simulations, to avoid a posteriori bias. For the first time, we detect the signature of voids in CMB lensing: the significance is 3.2σ, close to ΛCDM in both amplitude and projected densityprofile shape. A temperature dip is also seen, at modest significance (2.3σ), with amplitude about 6 times the prediction. This temperature signal is induced mostly by voids with radius between 100 and 150 h −1 Mpc, while the lensing signal is mostly contributed by smaller voids -as expected; lensing relates directly to density, while ISW depends on gravitational potential. The void abundance in observations and simulations agree, as well. We also repeated the analysis excluding lower-significance voids: no lensing signal is detected, with an upper limit of about twice the ΛCDM prediction. But the mean temperature decrement now becomes non-zero at the 3.7σ level (similar to that found by Granett et al.), with amplitude about 20 times the prediction. However, the observed dependence of temperature on void size is in poor agreement with simulations, whereas the lensing results are consistent with ΛCDM theory. Thus, the overall tension between theory and observations does not favour non-standard theories of gravity, despite the hints of an enhanced amplitude for the ISW effect from voids.

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The integrated Sachs–Wolfe signal from BOSS superstructures

Cited by 35 publications

References 53 publications

The part and the whole: voids, supervoids, and their ISW imprint

The part and the whole: voids, supervoids, and their ISW imprint

Cross-correlating Planck with VST ATLAS LRGs: a new test for the ISW effect in the Southern hemisphere

The lensing and temperature imprints of voids on the cosmic microwave background

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