Detection of Non‐Gaussianity in the<i>Wilkinson Microwave Anisotropy Probe</i>First‐Year Data Using Spherical Wavelets

Vielva, P.; Martínez-González, E.; Barreiro, R. B.; Sanz, J. L.; Cayón, L.

doi:10.1086/421007

Cited by 478 publications

(726 citation statements)

References 42 publications

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“…It was first detected in the Wilkinson Microwave Anisotropy Probe (Bennett et al 2013) maps at 3σ significance using wavelet filtering (Vielva et al 2004;Cruz et al 2005). The CS is perhaps the most significant among the 'anomalies', potential departures from isotropic and/or Gaussian statistics, and all confirmed by Planck (Planck Collaboration XXIII 2014).…”

Section: Introductionmentioning

confidence: 99%

“…We defined the centre of the CS from the latest Planck results (Planck Collaboration XXIV 2014). Based on the literature, we decided in advance to test for an underdensity at 5 • (Vielva et al 2004;Cruz et al 2005;Rudnick et al 2007;Bremer et al 2010;Granett et al 2010) and 15 • (Inoue et al 2010;Zhang & Huterer 2010) of radii. The fact that these values gleaned from CMB independently of our (large-scale structure) data simplifies the interpretation of our results in the Bayesian framework, in particular, minimize any a posteriori bias.…”

Section: Introductionmentioning

confidence: 99%

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Detection of a supervoid aligned with the cold spot of the cosmic microwave background

Szapudi¹,

Kovács²,

Granett³

et al. 2015

Monthly Notices of the Royal Astronomical Society

121

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We use the WISE-2MASS infrared galaxy catalog matched with Pan-STARRS1 (PS1) galaxies to search for a supervoid in the direction of the Cosmic Microwave Background Cold Spot. Our imaging catalog has median redshift z ≃ 0.14, and we obtain photometric redshifts from PS1 optical colours to create a tomographic map of the galaxy distribution. The radial profile centred on the Cold Spot shows a large low density region, extending over 10's of degrees. Motivated by previous Cosmic Microwave Background results, we test for underdensities within two angular radii, 5 • , and 15 • . The counts in photometric redshift bins show significantly low densities at high detection significance, ∼ > 5σ and ∼ > 6σ, respectively, for the two fiducial radii. The line-of-sight position of the deepest region of the void is z ≃ 0.15 − 0.25. Our data, combined with an earlier measurement by Granett et al. (2010), are consistent with a large R void = (220 ± 50)h −1 Mpc supervoid with δ m ≃ −0.14 ± 0.04 centered at z = 0.22 ± 0.03. Such a supervoid, constituting at least a ≃ 3.3σ fluctuation in a Gaussian distribution of the ΛCDM model, is a plausible cause for the Cold Spot.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Detection of a supervoid aligned with the cold spot of the cosmic microwave background

Szapudi¹,

Kovács²,

Granett³

et al. 2015

Monthly Notices of the Royal Astronomical Society

121

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“…The cosmic microwave background (CMB) Cold Spot (CS) anomaly was discovered by Vielva et al (2004) using the Spherical Mexican Hat Wavelet (SMHW) (Cayón et al 2001) on WMAP data. The anomaly has persisted (Cruz et al 2007;Bennett et al 2011) and was later verified by Planck (Planck Collaboration et al 2016b).…”

Section: Introductionmentioning

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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“…Vielva et al (2004) and Cruz et al (2005) showed that all the detectors measured an almost constant amplitude of the CS and proved that the instrumental noise was not affecting the results. Mukherjee & Wang (2004) found that the results were robust using different exclusion masks.…”

Section: Originmentioning

confidence: 80%

The WMAP Cold Spot

Cruz¹,

Martínez-González²,

Vielva³

2010

Astrophysics and Space Science Proceedings

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The WMAP cold spot was found by applying spherical wavelets to the first year WMAP data. An excess of kurtosis of the wavelet coefficient was observed at angular scales of around 5 degrees. This excess was shown to be inconsistent with Gaussian simulations with a p-value of around 1%. A cold spot centered at (b = −57 • , l = 209 • ) was shown to be the main cause of this deviation. Several hypotheses were raised to explain the origin of the cold spot. After performing a Bayesian template fit a collapsing cosmic texture was found to be the most probable hypothesis explaining the spot. Here we review the properties of the cold spot and the possible explanations.

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Detection of Non‐Gaussianity in theWilkinson Microwave Anisotropy ProbeFirst‐Year Data Using Spherical Wavelets

Cited by 478 publications

References 42 publications

Detection of a supervoid aligned with the cold spot of the cosmic microwave background

Detection of a supervoid aligned with the cold spot of 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

The WMAP Cold Spot

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