A Detection of the Integrated Sachs–wolfe Imprint of Cosmic Superstructures Using a Matched-Filter Approach

Nadathur, Seshadri; Crittenden, Robert

doi:10.3847/2041-8205/830/1/l19

Cited by 75 publications

(84 citation statements)

References 41 publications

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“…REVOLVER provides an option to remove RSD in the void positions through using density-field reconstruction prior to void finding (Nadathur et al 2019a,b), but this step has a negligibly small effect on the predicted lensing signal of voids, so is omitted here. Thus our void-finding procedure matches that previously used by Nadathur & Crittenden (2016).…”

Section: Boss Data and Void Catalogsupporting

confidence: 71%

The Gravitational Lensing Signatures of BOSS Voids in the Cosmic Microwave Background

Raghunathan

Nadathur

Sherwin

et al. 2020

ApJ

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We report a 5.3σ detection of the gravitational lensing effect of cosmic voids from the Baryon Oscillation Spectroscopic (BOSS) Data Release 12 seen in the Planck 2018 cosmic microwave background (CMB) lensing convergence map. To make this detection, we introduce new optimal techniques for void stacking and filtering of the CMB maps, such as binning voids by a combination of their observed galaxy density and size to separate those with distinctive lensing signatures. We calibrate theoretical expectations for the void-lensing signal using mock catalogs generated in a suite of 108 full-sky lensing simulations from Takahashi et al. (2017). Relative to these templates, we measure the lensing amplitude parameter in the data to be A L = 1.10 ± 0.21 using a matched-filter stacking technique, and confirm it using an alternative Wiener filtering method. We demonstrate that the result is robust against thermal Sunyaev-Zel'dovich contamination and other sources of systematics. We use the lensing measurements to test the relationship between the matter and galaxy distributions within voids, and show that the assumption of linear bias with a value consistent with galaxy clustering results is discrepant with observation at ∼ 3σ; we explain why such a result is consistent with simulations and previous results, and is expected as a consequence of void selection effects. We forecast the potential for void-CMB lensing measurements in future data from the Advanced ACT, Simons Observatory and CMB-S4 experiments, showing that, for the same number of voids, the achievable precision improves by a factor of more than two compared to Planck.Unified Astronomy Thesaurus concepts: Cosmology (343); Cosmic microwave background radiation (322); Weak gravitational lensing (1797); Large-scale structure of the universe (902); Voids (1779)

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Section: Boss Data and Void Catalogsupporting

confidence: 71%

The Gravitational Lensing Signatures of BOSS Voids in the Cosmic Microwave Background

Raghunathan

Nadathur

Sherwin

et al. 2020

ApJ

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“…This would mean the primordial CS profile is even less significant than measured. Alternative models, which are not investigated here, may explain the slightly higher than expected causal relation between the observed and expected ISW of large voids seen in certain studies (Granett et al 2008;Cai et al 2014;Kovács et al 2017;Kovács 2017) but not all (Ilić et al 2013;Hotchkiss et al 2015;Nadathur & Crittenden 2016). Whether this is the case could be studied in future and would have implications for the predicted ISW contribution to the CS.…”

Section: Discussionmentioning

confidence: 99%

The cosmic microwave background Cold Spot anomaly: the impact of sky masking and the expected contribution from the integrated Sachs–Wolfe effect

Naidoo

Benoit-Lévy

Lahav

2017

Monthly Notices of the Royal Astronomical Society: Letters

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We re-analyse the cosmic microwave background (CMB) Cold Spot (CS) anomaly with particular focus on understanding the bias a mask (contaminated by Galactic and point sources) may introduce. We measure the coldest spot, found by applying the Spherical Mexican Hat Wavelet transform on 100,000 cut-sky (masked) and fullsky CMB simulated maps. The CS itself is barely affected by the mask; we estimate a 94 per cent probability that the CS is the full-sky temperature minimum. However, ∼48 per cent (masked fraction of the mask) of full-sky minima are obscured by the mask. Since the observed minima are slightly hotter than the full-sky ensemble of minima, a cut-sky analysis would have found the CS to be significant at ∼2.2σ with a wavelet angular scale of R = 5 • . None the less, comparisons to full-sky minima show the CS significance to be only ∼1.9σ and <2σ for all R. The CS on the last scattering surface may be hotter due to the Integrated Sachs-Wolfe effect in the line of sight. However, our simulations show that this is on average only ∼10 per cent (about 10µK but consistent with zero) of the CS temperature profile. This is consistent with Lambda and Cold Dark Matter reconstructions of this effect based on observed line-of-sight voids.

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“…Early attempts at measuring the ISW signal using the cross-correlation method, include an analysis of the COBE CMB map by Boughn & Crittenden (2002) followed by detections of the signal using the WMAP CMB data, albeit often at relatively low to moderate levels of significance (Scranton et al 2003;Nolta et al 2004;Boughn & Crittenden 2004;Corasaniti et al 2005;Padmanabhan et al 2005;Giannantonio et al 2006;Cabré et al 2006;Rassat et al 2007; Raccanelli et al 2008;Granett et al 2009;Bielby et al 2010;Sawangwit et al 2010;Kovács et al 2013). Other studies have however claimed detections in the range of 3 − 5σ (Fosalba et al 2003;Fosalba & Gaztañaga 2004;Vielva et al 2006;McEwen et al 2006;Giannantonio et al 2008;Ho et al 2008;Granett et al 2008;Giannantonio et al 2012;Goto et al 2012;Planck Collaboration et al 2016c).…”

Section: Introductionmentioning

confidence: 99%

“…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 Detection of the Integrated Sachs–wolfe Imprint of Cosmic Superstructures Using a Matched-Filter Approach

Cited by 75 publications

References 41 publications

The Gravitational Lensing Signatures of BOSS Voids in the Cosmic Microwave Background

The Gravitational Lensing Signatures of BOSS Voids in the Cosmic Microwave Background

The cosmic microwave background Cold Spot anomaly: the impact of sky masking and the expected contribution from the integrated Sachs–Wolfe effect

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

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