Maximum likelihood algorithm for parametric component separation in cosmic microwave background experiments

Stompor, R.; Leach, S.; Stivoli, F.; Baccigalupi, C.

doi:10.1111/j.1365-2966.2008.14023.x

Cited by 98 publications

(134 citation statements)

References 39 publications

Supporting

Mentioning

133

Contrasting

Order By: Relevance

“…In our real space implementation, we explore model parameters through Bayesian parameter estimation techniques, fitting a parametric signal model per pixel (Commander; Eriksen et al 2006Eriksen et al , 2008; a similar implementation is presented by Stompor et al (2009). To estimate spectral indices robustly in pixel space, this procedure requires identical angular resolution across all frequencies included in the analysis, and is therefore limited in resolution by the 30 GHz LFI channel.…”

Section: Approach To Component Separationmentioning

confidence: 99%

Planck2013 results. XII. Diffuse component separation

Ade¹,

Aghanim²,

Armitage-Caplan³

et al. 2014

A&A

229

View full text Add to dashboard Cite

Planck has produced detailed all-sky observations over nine frequency bands between 30 and 857 GHz. These observations allow robust reconstruction of the primordial cosmic microwave background (CMB) temperature fluctuations over nearly the full sky, as well as new constraints on Galactic foregrounds, including thermal dust and line emission from molecular carbon monoxide (CO). This paper describes the component separation framework adopted by Planck for many cosmological analyses, including CMB power spectrum determination and likelihood construction on large angular scales, studies of primordial non-Gaussianity and statistical isotropy, the integrated Sachs-Wolfe effect, gravitational lensing, and searches for topological defects. We test four foreground-cleaned CMB maps derived using qualitatively different component separation algorithms. The quality of our reconstructions is evaluated through detailed simulations and internal comparisons, and shown through various tests to be internally consistent and robust for CMB power spectrum and cosmological parameter estimation up to = 2000. The parameter constraints on ΛCDM cosmologies derived from these maps are consistent with those presented in the cross-spectrum based Planck likelihood analysis. We choose two of the CMB maps for specific scientific goals. We also present maps and frequency spectra of the Galactic low-frequency, CO, and thermal dust emission. The component maps are found to provide a faithful representation of the sky, as evaluated by simulations, with the largest bias seen in the CO component at 3%. For the low-frequency component, the spectral index varies widely over the sky, ranging from about β = −4 to −2. Considering both morphology and prior knowledge of the low frequency components, the index map allows us to associate a steep spectral index (β < −3.2) with strong anomalous microwave emission, corresponding to a spinning dust spectrum peaking below 20 GHz, a flat index of β > −2.3 with strong free-free emission, and intermediate values with synchrotron emission.

show abstract

Section: Approach To Component Separationmentioning

confidence: 99%

Planck2013 results. XII. Diffuse component separation

Ade¹,

Aghanim²,

Armitage-Caplan³

et al. 2014

A&A

229

View full text Add to dashboard Cite

show abstract

“…We focus on a particular component separation method and power spectrum estimation approach, which we then use to investigate the impact of the foreground separation on the CMB B‐mode detection and characterization. The component separation method is a maximum likelihood (ML) parametric approach (Eriksen et al 2006) in a two‐step implementation of Stompor et al (2009). The power spectrum estimator is a ‘pure’ pseudo‐spectrum approach introduced by Smith (2006) (see also Smith & Zaldarriaga 2007) and elaborated on by Grain, Tristram & Stompor (2009).…”

Section: Introductionmentioning

confidence: 99%

Maximum likelihood, parametric component separation and CMB B-mode detection in suborbital experiments

Stivoli

Grain

Leach

et al. 2010

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We investigate the performance of the parametric maximum likelihood component separation method in the context of the cosmic microwave background (CMB) B-mode signal detection and its characterization by small-scale CMB suborbital experiments. We consider high-resolution (FWHM = 8') balloon-borne and ground-based observatories mapping low dust-contrast sky areas of 400 and 1000 square degrees, in three frequency channels, 150, 250, 410 GHz, and 90, 150, 220 GHz, with sensitivity of order 1 to 10μK per beam-size pixel. These are chosen to be representative of some of the proposed, next-generation, bolometric experiments. We study the residual foreground contributions left in the recovered CMB maps in the pixel and harmonic domain and discuss their impact on a determination of the tensor-to-scalar ratio, r. In particular, we find that the residuals derived from the simulated data of the considered balloon-borne observatories are sufficiently low not to be relevant for the B-mode science. However, the ground-based observatories are in need of some external information to permit satisfactory cleaning. We find that if such information is indeed available in the latter case, both the ground-based and balloon-borne experiments can detect the values of r as low as ~0.04 at 95 per cent confidence level. The contribution of the foreground residuals to these limits is found to be then subdominant and these are driven by the statistical uncertainty due to CMB, including E-to-B leakage, and noise. We emphasize that reaching such levels will require a sufficient control of the level of systematic effects present in the data

show abstract

“…In order to separate the different components that make up the total sky emission we have adopted here a map-based Bayesian scheme [15,[45][46][47][48]. An advantage of map-based methods over power-spectrum-based foreground cleaning (e.g.…”

Section: Map-based Component Separationmentioning

confidence: 99%

Simulated forecasts for primordial B -mode searches in ground-based experiments

et al. 2017

View full text Add to dashboard Cite

Detecting the imprint of inflationary gravitational waves on the B-mode polarization of the Cosmic Microwave Background (CMB) is one of the main science cases for current and next-generation CMB experiments. In this work we explore some of the challenges that ground-based facilities will have to face in order to carry out this measurement in the presence of Galactic foregrounds and correlated atmospheric noise. We present forecasts for Stage-3 (S3) and planned Stage-4 (S4) experiments based on the analysis of simulated sky maps using a map-based Bayesian foreground cleaning method. Our results thus consistently propagate the uncertainties on foreground parameters such as spatiallyvarying spectral indices, as well as the bias on the measured tensor-to-scalar ratio r caused by an incorrect modelling of the foregrounds. We find that S3 and S4-like experiments should be able to put constraints on r of the order σ(r) = (0.5 − 1.0) × 10 −2 and σ(r) = (0.5 − 1.0) × 10 −3 respectively, assuming instrumental systematic effects are under control. We further study deviations from the fiducial foreground model, finding that, while the effects of a second polarized dust component would be minimal on both S3 and S4, a 2% polarized anomalous dust emission (AME) component would be clearly detectable by Stage-4 experiments.

show abstract

Maximum likelihood algorithm for parametric component separation in cosmic microwave background experiments

Cited by 98 publications

References 39 publications

Planck2013 results. XII. Diffuse component separation

Planck2013 results. XII. Diffuse component separation

Maximum likelihood, parametric component separation and CMB B-mode detection in suborbital experiments

Simulated forecasts for primordial B -mode searches in ground-based experiments

Contact Info

Product

Resources

About