Cosmic microwave background reconstruction from WMAP and<i>Planck</i>PR2 data

Bobin, J.; Sureau, F.; Starck, Jean-Luc

doi:10.1051/0004-6361/201527822

Cited by 39 publications

(35 citation statements)

References 34 publications

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“…We find a similar behaviour for the even/odd multipole common axes in WMAP provided nine year Internal Linear Combination 6 (ILC) map (Bennett et al 2013), and the Local-generalized Morphological Component Analysis (LGMCA) map that was produced using both the WMAP and PLANCK full mission observations 7 (Bobin, Sureau & Starck 2016). We also checked collective alignment axes in multipole blocks of ∆l = 6 from the same range l = [2, 61], with three even/odd multipoles in each block.…”

Section: Parity Alignmentsmentioning

confidence: 59%

Alignments of parity even/odd-only multipoles in CMB

Aluri

Ralston

Weltman

2017

Monthly Notices of the Royal Astronomical Society

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We compare the statistics of parity even and odd multipoles of the cosmic microwave background (CMB) sky from PLANCK full mission temperature measurements. An excess power in odd multipoles compared to even multipoles has previously been found on large angular scales. Motivated by this apparent parity asymmetry, we evaluate directional statistics associated with even compared to odd multipoles, along with their significances. Primary tools are the Power Tensor and Alignment Tensor statistics. We limit our analysis to the first sixty multipoles i.e., l = [2, 61]. We find no evidence for statistically unusual alignments of even parity multipoles. More than one independent statistic finds evidence for alignments of anisotropy axes of odd multipoles, with a significance equivalent to ∼ 2σ or more. The robustness of alignment axes is tested by making galactic cuts and varying the multipole range. Very interestingly, the region spanned by the (a)symmetry axes is found to broadly contain other parity (a)symmetry axes previously observed in the literature.

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Section: Parity Alignmentsmentioning

confidence: 59%

Alignments of parity even/odd-only multipoles in CMB

Aluri

Ralston

Weltman

2017

Monthly Notices of the Royal Astronomical Society

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“…We have first subtracted the CMB intensity as modelled at 70 GHz by Bobin et al (2016) from the joint analysis of WMAP and Planck observations. We have then taken advantage of the sparse spatial correlation between the thermal dust intensity I 70 at 70 GHz and the dust optical depth τ 353 at 353 GHz in the wavelet domain to filter out the dust component.…”

Section: Appendix A: Component Separationmentioning

confidence: 99%

Cosmic rays, gas and dust in nearby anticentre clouds

Remy

Grenier

Marshall

et al. 2017

A&A

187

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Aims. We aim to explore the capabilities of dust emission and γ rays for probing the properties of the interstellar medium in the nearby anti-centre region, using γ-ray observations with the Fermi Large Area Telescope (LAT), and the thermal dust optical depth inferred from Planck and IRAS observations. We also aim to study massive star-forming clouds including the well known Taurus, Auriga, Perseus, and California molecular clouds, as well as a more diffuse structure which we refer to as Cetus. In particular, we aim at quantifying potential variations in cosmic-ray density and dust properties per gas nucleon across the different gas phases and different clouds, and at measuring the CO-to-H 2 conversion factor, X CO , in different environments. Methods. We have separated six nearby anti-centre clouds that are coherent in velocities and distances, from the Galactic-disc background in H i 21-cm and 12 CO 2.6-mm line emission. We have jointly modelled the γ-ray intensity recorded between 0.4 and 100 GeV, and the dust optical depth τ 353 at 353 GHz as a combination of H i -bright, CO-bright, and ionised gas components. The complementary information from dust emission and γ rays was used to reveal the gas not seen, or poorly traced, by H i , free-free, and 12 CO emissions, namely (i) the opaque H i and diffuse H 2 present in the Dark Neutral Medium at the atomic-molecular transition, and (ii) the dense H 2 to be added where 12 CO lines saturate. Results. The measured interstellar γ-ray spectra support a uniform penetration of the cosmic rays with energies above a few GeV through the clouds, from the atomic envelopes to the 12 CO-bright cores, and with a small ±9% cloud-to-cloud dispersion in particle flux. We detect the ionised gas from the H ii region NGC1499 in the dust and γ-ray emissions and measure its mean electron density and temperature. We find a gradual increase in grain opacity as the gas (atomic or molecular) becomes more dense. The increase reaches a factor of four to six in the cold molecular regions that are well shielded from stellar radiation. Consequently, the X CO factor derived from dust is systematically larger by 30% to 130% than the γ-ray estimate. We also evaluate the average γ-ray X CO factor for each cloud, and find that X CO tends to decrease from diffuse to more compact molecular clouds, as expected from theory. We find X CO factors in the anti-centre clouds close to or below 10 20 cm −2 K −1 km −1 s, in agreement with other estimates in the solar neighbourhood. Together, they confirm the long-standing unexplained discrepancy, by a factor of two, between the mean X CO values measured at parsec scales in nearby clouds and those obtained at kiloparsec scale in the Galaxy. Our results also highlight large quantitative discrepancies in 12 CO intensities between simulations and observations at low molecular gas densities.

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“…The premise method for estimating thermal dust requires for the CMB to be removed from the total intensity maps. For this we use the CMB estimate of Bobin et al (2016).…”

Section: Cmbmentioning

confidence: 99%

Determining thermal dust emission from Planck HFI data using a sparse, parametric technique

Irfan

Bobin

Miville-Deschênes

et al. 2019

A&A

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Context. The Planck data releases have provided the community with sub-millimetre and radio observations of the full-sky at unprecedented resolutions. We make use of the Planck 353, 545 and 857 GHz maps alongside the IRAS 3000 GHz map. These maps contain information on the cosmic microwave background (CMB), cosmic infrared background (CIB), extragalactic point sources and diffuse thermal dust emission. Aims. We aim to determine the modified black body (MBB) model parameters of thermal dust emission in total intensity and produce all sky maps of pure thermal dust, having separated this Galactic component from the CMB and CIB.Methods. This separation is completed using a new, sparsity-based, parametric method which we refer to as premise. The method comprises of three main stages: 1) filtering of the raw data to reduce the effect of the CIB on the MBB fit. 2) fitting an MBB model to the filtered data across super-pixels of various sizes determined by the algorithm itself and 3) refining these super-pixel estimates into full resolution maps of the MBB parameters. Results. We present our maps of MBB temperature, spectral index and optical depth at 5 arcmin resolution and compare our estimates to those of GNILC as well as the two-step MBB fit presented by the Planck collaboration in 2013. Conclusions. By exploiting sparsity we avoid the need for smoothing, enabling us to produce the first full resolution MBB parameter maps from intensity measurements of thermal dust emission. We consider the premise parameter estimates to be competitive with the existing state-of-the-art solutions, outperforming these methods within low signal-to-noise regions as we account for the CIB without removing thermal dust emission through over-smoothing.

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Cosmic microwave background reconstruction from WMAP andPlanckPR2 data

Cited by 39 publications

References 34 publications

Alignments of parity even/odd-only multipoles in CMB

Alignments of parity even/odd-only multipoles in CMB

Cosmic rays, gas and dust in nearby anticentre clouds

Determining thermal dust emission from Planck HFI data using a sparse, parametric technique

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