We revisit the question of hemispherical power asymmetry in the WMAP and Planck temperature sky maps by measuring the local variance over the sky and on disks of various sizes. For the 2013 Planck ...sky map we find that none of the 1000 available isotropic Planck "Full Focal Plane" simulations have a larger variance asymmetry than that estimated from the data, suggesting the presence of an anisotropic signature formally significant at least at the 3.3sigma level. For the WMAP 9 year data we find that 5 out of 1000 simulations have a larger asymmetry. The preferred direction for the asymmetry from the Planck data is (l, b) = (212degrees, -13degrees), in good agreement with previous reports of the same hemispherical power asymmetry.
We extend previous work modelling the Galactic magnetic field in the plane using synchrotron emission in total and polarized intensity. In this work, we include a more realistic treatment of the ...cosmic ray electrons using the galprop propagation code optimized to match the existing high-energy data. This addition reduces the degeneracies in our previous analysis and when combined with an additional observed synchrotron frequency allows us to study the low-energy end of the cosmic ray electron spectrum in a way that has not previously been done. For a pure diffusion propagation, we find a low-energy injection spectrum slightly harder than generally assumed: for J(E) ∝E
α, we find α=−1.34 ± 0.12, implying a very sharp break with the spectrum above a few GeV. This then predicts a synchrotron brightness temperature spectral index, β, on the Galactic plane, that is −2.8 < β < −2.74 below a few GHz and −2.98 < β < −2.91 up to 23 GHz. We find that models including cosmic ray re-acceleration processes appear to be incompatible with the synchrotron data.
ABSTRACT
We apply the Gabor transform methodology proposed by Hansen et al. to the WMAP data in order to test the statistical properties of the cosmic microwave background (CMB) fluctuation field and ...specifically to evaluate the fundamental assumption of cosmological isotropy. In particular, we apply the transform with several apodization scales, thus allowing the determination of the positional dependence of the angular power spectrum with either high spatial localization or high angular resolution (i.e. narrow bins in multipole space). Practically, this implies that we estimate the angular power spectrum locally in discs of various sizes positioned in different directions: small discs allow the greatest sensitivity to positional dependence, whereas larger discs allow greater sensitivity to variations over different angular scales. In addition, we determine whether the spatial position of a few outliers in the angular power spectrum could suggest the presence of residual foregrounds or systematic effects. For multipoles close to the first peak, the most deviant local estimates from the best‐fitting WMAP model are associated with a few particular areas close to the Galactic plane. Such deviations also include the ‘dent’ in the spectrum just shortward of the first peak which was remarked upon by the WMAP team. Estimating the angular power spectrum excluding these areas gives a slightly higher first Doppler peak amplitude.
Finally, we probe the isotropy of the largest angular scales by estimating the power spectrum on hemispheres and reconfirm strong indications of a north–south asymmetry previously reported by other authors. Indeed, there is a remarkable lack of power in a region associated with the North ecliptic Pole. With the greater fidelity in ℓ‐space allowed by this larger sky coverage, we find tentative evidence for residual foregrounds in the range ℓ= 2–4, which could be associated with the low measured quadrupole amplitudes and other anomalies on these angular scales (e.g. planarity and alignment). However, over the range ℓ= 5–40 the observed asymmetry is much harder to explain in terms of residual foregrounds and known systematic effects.
By reorienting the coordinate axes, we partition the sky into different hemispheres and search for the reference frame which maximizes the asymmetric distribution of power. The North Pole for this coordinate frame is found to intersect the sphere at (80°, 57°) in Galactic colatitude and longitude over almost the entire multipole range ℓ= 5–40. Furthermore, the strong negative outlier at ℓ= 21 and the strong positive outlier at ℓ= 39, as determined from the global power spectrum by the WMAP team, are found to be associated with the Northern and Southern hemispheres, respectively (in this frame of maximum asymmetry). Thus, these two outliers follow the general tendency of the multipoles ℓ= 5–40 to be of systematically lower amplitude in the north and higher in the south. Such asymmetric distributions of power on the sky provide a serious test for the cosmological principle of isotropy.
We present cosmological parameter constraints using maps from the last
Planck
data release (PR4). In particular, we detail an upgraded version of the cosmic microwave background likelihood,
HiLLiPoP
..., that is based on angular power spectra and relies on a physical modeling of the foreground residuals in the spectral domain. This new version of the likelihood retains a larger sky fraction (up to 75%) and uses an extended multipole range. Using this likelihood, along with low-
ℓ
measurements from
LoLLiPoP
, we derived constraints on ΛCDM parameters that are in good agreement with previous
Planck
2018 results, but with smaller uncertainties by 10% to 20%. We demonstrate that the foregrounds can be accurately described in the spectral domain, with a negligible impact on ΛCDM parameters. We also derived constraints on single-parameter extensions to ΛCDM, including
A
L
, Ω
K
,
N
eff
, and ∑
m
ν
. Noteworthy results from this updated analysis include a lensing amplitude value of
A
L
= 1.039 ± 0.052, which is more closely aligned with theoretical expectations within the ΛCDM framework. Additionally, our curvature measurement, Ω
K
= −0.012 ± 0.010, is now fully consistent with a flat universe and our measurement of
S
8
is closer to the measurements derived from large-scale structure surveys (at the 1.5
σ
level). We also added constraints from PR4 lensing, making this combination the most tightly constrained data set currently available from
Planck
. Additionally, we explored the addition of baryon acoustic oscillation data, which tightens the limits on some particular extensions to the standard cosmology.
Abstract
The bright polarized synchrotron emission, away from the Galactic plane, originates mostly from filamentary structures. We implement a filament finder algorithm which allows the detection of ...bright elongated structures in polarized intensity maps. We analyse the sky at 23 and 30 GHz as observed respectively by
WMAP
and
Planck
. We identify 19 filaments, 13 of which have been previously observed. For each filament, we study the polarization fraction, finding values typically larger than for the areas outside the filaments, excluding the Galactic plane, and a fraction of about 30% is reached in two filaments. We study the polarization spectral indices of the filaments, and find a spectral index consistent with the values found in previous analysis (about -3.1) for more diffuse regions. Decomposing the polarization signals into the
E
and
B
families, we find that most of the filaments are detected in
P
E
, but not in
P
B
. We then focus on understanding the statistical properties of the diffuse regions of the synchrotron emission at 23 GHz. Using Minkowski functionals and tensors, we analyse the non-Gaussianity and statistical isotropy of the polarized intensity maps. For a sky coverage corresponding to 80% of the fainter emission, and on scales smaller than 6 degrees (ℓ > 30), the deviations from Gaussianity and isotropy are significantly higher than 3
σ
. The level of deviation decreases for smaller scales, however, it remains significantly high for the lowest analised scale (∼ 1.5°). When 60% sky coverage is analysed, we find that the deviations never exceed 3
σ
. Finally, we present a simple data-driven model to generate non-Gaussian and anisotropic simulations of the synchrotron polarized emission. The simulations are fitted in order to match the spectral and statistical properties of the faintest 80% sky coverage of the data maps.
Motivated by the large-scale asymmetry observed in the cosmic microwave background sky, we consider a specific class of anisotropic cosmological models--Bianchi type VII sub(h)--and compare them to ...the WMAP first-year data on large angular scales. Remarkably, we find evidence of a correlation that is ruled out as a chance alignment at the 3 s level. The best-fit Bianchi model corresponds to x = 0.55, sub(0) = 0.5, a rotation axis in the direction (l, b) = (222, -62), shear (s/H) sub(0) = 2.4 x 10 super(-10), and a right-handed vorticity (w/H) sub(0) = 4.3 x 10 super(-10). Correcting for this component greatly reduces the significance of the large-scale power asymmetry, resolves several anomalies detected on large angular scales (i.e., the low quadrupole amplitude and quadrupole/octopole planarity and alignment), and can account for a non-Gaussian "cold spot" on the sky. Despite the apparent inconsistency with the best-fit parameters required in inflationary models to account for the acoustic peaks, we consider the results sufficiently provocative to merit further consideration.
As the next step towards an improved large-scale Galactic magnetic field model, we present a simple comparison of polarized synchrotron and thermal dust emission on the Galactic plane. We find that ...the field configuration in our previous model that reproduces the polarized synchrotron is not compatible with the Wilkinson Microwave Anisotropy Probe (WMAP) 94 GHz polarized emission data. In particular, the high degree of dust polarization in the outer Galaxy (90° < < 270°) implies that the fields in the dust-emitting regions are more ordered than the average of synchrotron-emitting regions. This new dust information allows us to constrain the spatial mixing of the coherent and random magnetic field components in the outer Galaxy. The inner Galaxy differs in polarization degree and apparently requires a more complicated scenario than our current model. In the scenario that each interstellar component (including fields and now dust) follows a spiral-arm modulation, as observed in external galaxies, the changing degree of ordering of the fields in dust-emitting regions may imply that the dust arms and the field component arms are shifted as a varying function of Galactocentric radius. We discuss the implications for how the spiral-arm compression affects the various components of the magnetized interstellar medium, but conclude that improved data such as that expected from the Planck satellite will be required for a thorough analysis.
The poor mental health of adults living in aged care needs addressing. Improvements to nutrition and exercise are important, but mental health requires a psychological approach. Self-determination ...theory finds that autonomy is essential to wellbeing while experiences of being controlled undermine it. A review of existing quantitative data could underscore the importance of autonomy in aged care, and a review of the qualitative literature could inform ways to promote autonomy and avoid control. Testing these possibilities was the objective of this research.
We conducted a mixed-methods systematic review of studies investigating autonomy, control, and indices of optimal functioning in aged care settings. The search identified 30 eligible reports (19 quantitative, 11 qualitative), including 141 quantitative effect sizes, 84 qualitative data items, and N = 2,668. Quantitative effects were pooled using three-level meta-analytic structural equation models, and the qualitative data were meta-synthesized using a grounded theory approach.
As predicted, the meta-analysis showed a positive effect of aged care residents' autonomy and their wellness, r = 0.33 95% CI: 0.27, 0.39, and a negative effect of control, r = -0.16 95% CI: -0.27, -0.06. The meta-synthesis revealed seven primary and three sub-themes describing the nuanced ways autonomy, control, and help seeking are manifest in residential aged care settings.
The results suggest that autonomy should be supported, and unnecessary external control should be minimized in residential aged care, and we discuss ways the sector could strive for both aims.
We present a method for parametric modelling of the physical components of the Galaxy's magnetized interstellar medium, simulating the observables and mapping out the likelihood space using a Markov ...Chain Monte Carlo analysis. We then demonstrate it using total and polarized synchrotron emission data as well as rotation measures of extragalactic sources. With these three data sets, we define and study three components of the magnetic field: the large-scale coherent field, the small-scale isotropic random field and the ordered field. In this first paper, we use only data along the Galactic plane and test a simple two-dimensional (2D) logarithmic spiral model for the magnetic field that includes a compression and a shearing of the random component giving rise to an ordered component. We demonstrate with simulations that the method can indeed constrain multiple parameters yielding measures of, for example, the ratios of the magnetic field components. Though subject to uncertainties in thermal and cosmic ray electron densities and depending on our particular model parametrization, our preliminary analysis shows that the coherent component is a small fraction of the total magnetic field and an ordered component comparable in strength to the isotropic random component is required to explain the polarization fraction of synchrotron emission. We outline further work to extend this type of analysis to study the magnetic spiral arm structure, the details of the turbulence as well as the 3D structure of the magnetic field.
We consider the issue of hemispherical power asymmetry in the third-year WMAP data, adopting a previously introduced modulation framework. Computing both frequentist probabilities and Bayesian ...evidences, we find that the model consisting of an isotropic CMB sky modulated by a dipole field gives a substantially better fit to the observations than the purely isotropic model, even when accounting for the larger prior volume. For the ILC map, the Bayesian log-evidence difference is similar to 1.8 in favor of the modulated model, and the raw improvement in maximum log likelihood is 6.1. The best-fit modulation dipole axis points toward (l, b) = (225 degree , -27 degree ), and the modulation amplitude is 0.114, in excellent agreement with the results from the first-year analyses. The frequentist probability of obtaining such a high modulation amplitude in an isotropic universe is similar to 1%. These results are not sensitive to data set or sky cut. Thus, the statistical evidence for a power asymmetry anomaly is both substantial and robust, although not decisive, for the currently available data. Increased sky coverage through better foreground handling and full-sky and high-sensitivity polarization maps may shed further light on this issue.
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