High resolution foreground cleaned CMB map from WMAP

Tegmark, Max; Oliveira-Costa, A. de; Hamilton, A.

doi:10.1103/physrevd.68.123523

Cited by 595 publications

(852 citation statements)

References 60 publications

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“…Bennett et al (2003) used the ILC method in pixel space. Later, the ILC method was used in harmonic space by Tegmark et al (2003) and in wavelet space by Delabrouille et al (2009). Finally, Remazeilles, Delabrouille, & Cardoso (2011) developed an extension of the ILC method in wavelet space that makes use of a prior for the power spectrum of a specific component of the observed sky.…”

Section: Gnilc Methodsmentioning

confidence: 99%

Extracting H i cosmological signal with generalized needlet internal linear combination

Olivari¹,

Remazeilles²,

Dickinson³

2015

Mon. Not. R. Astron. Soc.

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HI intensity mapping is a new observational technique to map fluctuations in the large-scale structure of matter using the 21 cm emission line of atomic hydrogen (HI). Sensitive HI intensity mapping experiments have the potential to detect Baryon Acoustic Oscillations (BAO) at low redshifts (z 1) in order to constrain the properties of dark energy. Observations of the HI signal will be contaminated by instrumental noise and, more significantly, by astrophysical foregrounds, such as Galactic synchrotron emission, which is at least four orders of magnitude brighter than the HI signal. Foreground cleaning is recognised as one of the key challenges for future radio astronomy surveys. We study the ability of the Generalized Needlet Internal Linear Combination (GNILC) method to subtract radio foregrounds and to recover the cosmological HI signal for a general HI intensity mapping experiment. The GNILC method is a new technique that uses both frequency and spatial information to separate the components of the observed data. Our results show that the method is robust to the complexity of the foregrounds. For simulated radio observations including HI emission, Galactic synchrotron, Galactic free-free, radio sources and 0.05 mK thermal noise, we find that the GNILC method can reconstruct the HI power spectrum for multipoles 30 < < 150 with 6% accuracy on 50% of the sky for a redshift z ∼ 0.25.

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Section: Gnilc Methodsmentioning

confidence: 99%

Extracting H i cosmological signal with generalized needlet internal linear combination

Olivari¹,

Remazeilles²,

Dickinson³

2015

Mon. Not. R. Astron. Soc.

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“…We chose not to use either the WMAP "Internal Linear Combination" (ILC) map [26], or the foreground cleaned map of [28], to avoid a number of practical difficulties. These maps lose the frequency dependence of the original maps (useful to identify contaminating signals) and have complicated pixel-pixel noise correlations (increasing the complexity of the error analysis).…”

Section: Datamentioning

confidence: 99%

Correlating the CMB with luminous red galaxies: The integrated Sachs-Wolfe effect

et al. 2005

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We present a 2.5σ detection of the Integrated Sachs-Wolfe (ISW) effect and discuss the constraints it places on cosmological parameters. We cross-correlate microwave temperature maps from the WMAP satellite with a 4000 deg 2 luminous red galaxy (LRG) overdensity map measured by the Sloan Digital Sky Survey. These galaxies have accurate photometric redshifts (∆z ∼ 0.03) and an approximately volume limited redshift distribution from z ∼ 0.2 to z ∼ 0.6 well suited to detecting the ISW effect. Accurate photometric redshifts allow us to perform a reliable auto-correlation analysis of the LRGs, eliminating the uncertainty in the galaxy bias, and combined with cross correlation signal, constrains cosmological parameters -in particular, the matter density. We use a minimum variance power spectrum estimator that optimally weights the data according to expected theoretical templates. We find a 2.5σ signal in the Ka, Q, V, and W WMAP bands, after combining the information from multipoles 2 ≤ l < 400. This is consistent with the expected amplitude of the ISW effect, but requires a lower matter density than is usually assumed: the amplitude, parametrized by the galaxy bias assuming ΩM = 0.3, ΩΛ = 0.7 and σ8 = 0.9, is bg = 4.05 ± 1.54 for V band, with similar results for the other bands. This should be compared to bg = 1.82 ± 0.02 from the auto-correlation analysis. These data provide only a weak confirmation (2.5σ) of dark energy, but provide a significant upper limit: ΩΛ = 0.80 +0.03 −0.06 (1σ) +0.05 −0.19 (2σ), assuming a cosmology with ΩM + ΩΛ = 1, Ω b = 0.05, and σ8 = 0.9, and w = −1. The weak cross-correlation signal rules out low matter density/high dark energy density universes and, in combination with other data, strongly constrains models with w < −1.3. We provide a simple prescription to incorporate these constraints into cosmological parameter estimation methods for (ΩM , σ8, w). We find no evidence for a systematic contamination of ISW signal, either from Galactic or extragalactic sources, but we do detect some large statistical fluctuations on smaller scales that could affect analyses without the template weighting.

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“…As the improvements of accuracy, it is found from a large amount of observations that the Universe might deviate from statistical isotropy. These include the alignment of low multipoles in the angular power spectrum of CMB temperature fluctuations (Tegmark, de Oliveira-Costa & Hamilton 2003;Bielewicz, Gorski & Banday 2004;Copi et al 2010;Frommert & Enßlin 2010), the hemispherical power asymmetry of CMB temperature anisotropy (Bennett et al 2013;Ade et al 2014;Eriksen et al ⋆ e-mail: linhainanjyzjcn@163.com. † e-mail: wangsai@itp.ac.cn.…”

Section: Introductionmentioning

confidence: 99%

Testing the isotropy of the Universe by using the JLA compilation of Type Ia supernovae

Lin¹,

Wang²,

Chang³

et al. 2015

Mon. Not. R. Astron. Soc.

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We probe the possible anisotropy of the Universe by using the JLA compilation of type-Ia supernovae. We apply the Markov Chain Monte Carlo (MCMC) method to constrain the amplitude and direction of anisotropy in three cosmological models. For the dipole-modulated ΛCDM model, the anisotropic amplitude is consistent with zero at 68% C.L., and has an upper bound A D < 1.98 × 10 −3 at 95% C.L. Regardless of much larger uncertainty, we find the dipole direction of JLA is amazingly opposite to that of Union2. Similar results are found for the dipole-modulated wCDM and CPL models. Thus, the Universe is still well consistent with the isotropy according to the JLA compilation.

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High resolution foreground cleaned CMB map from WMAP

Cited by 595 publications

References 60 publications

Extracting H i cosmological signal with generalized needlet internal linear combination

Extracting H i cosmological signal with generalized needlet internal linear combination

Correlating the CMB with luminous red galaxies: The integrated Sachs-Wolfe effect

Testing the isotropy of the Universe by using the JLA compilation of Type Ia supernovae

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