Primordial magnetic fields (PMF) damp at scales smaller than the photon diffusion and free-streaming scale. This leads to heating of ordinary matter (electrons and baryons), which affects both the ...thermal and ionization history of our Universe. Here, we study the effect of heating due to ambipolar diffusion and decaying magnetic turbulence. We find that changes to the ionization history computed with recfast are significantly overestimated when compared with CosmoRec. The main physical reason for the difference is that the photoionization coefficient has to be evaluated using the radiation temperature rather than the matter temperature. A good agreement with CosmoRec is found after changing this aspect. Using Planck 2013 data and considering only the effect of PMF-induced heating, we find an upper limit on the rms magnetic field amplitude of B
0 ≲ 1.1 nG (95 per cent c.l.) for a stochastic background of PMF with a nearly scale-invariant power spectrum. We also discuss uncertainties related to the approximations for the heating rates and differences with respect to previous studies. Our results are important for the derivation of constraints on the PMF power spectrum obtained from measurements of the cosmic microwave background anisotropies with full-mission Planck data. They may also change some of the calculations of PMF-induced effects on the primordial chemistry and 21cm signals.
We use our most recent training set for the rico code to estimate the impact of recombination uncertainties on the posterior probability distributions which will be obtained from future cosmic ...microwave background experiments, and in particular the Planck satellite. Using a Monte Carlo Markov Chain (MCMC) analysis to sample the posterior distribution of the cosmological parameters, we find that Planck will have biases of −0.7, −0.3 and −0.4σ for nS, Ωbh2 and log(1010AS), respectively, in the minimal six-parameter Λ cold dark matter model, if the description of the recombination history given by rico is not used. The remaining parameters (e.g. τ or Ωdmh2) are not significantly affected. We also show that the cosmology dependence of the corrections to the recombination history modelled with rico has a negligible impact on the posterior distributions obtained for the case of the Planck satellite. In practice, this implies that the inclusion of additional corrections to existing recombination codes can be achieved using simple cosmology-independent ‘fudge functions’. Finally, we also investigated the impact of some recent improvements in the treatment of hydrogen recombination which are still not included in the current version of our training set for rico, by assuming that the cosmology dependence of those corrections can be neglected. In summary, with our current understanding of the complete recombination process, the expected biases in the cosmological parameters inferred from Planck might be as large as −2.3, −1.7 and −1σ for nS, Ωbh2 and log(1010AS), respectively, if all those corrections are not taken into account. We note that although the list of physical processes that could be of importance for Planck seems to be nearly complete, still some effort has to be put into the validation of the results obtained by the different groups. The new rico training set as well as the fudge functions used for this paper are publicly available on the rico webpage.
With the largest spectroscopic galaxy survey volume drawn from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), we can extract cosmological constraints from the measurements of redshift ...and geometric distortions at quasi-linear scales (e.g. above 50 h
−1 Mpc). We analyse the broad-range shape of the monopole and quadrupole correlation functions of the BOSS Data Release 12 (DR12) CMASS galaxy sample, at the effective redshift z = 0.59, to obtain constraints on the Hubble expansion rate H(z), the angular- diameter distance D
A
(z), the normalized growth rate f(z)σ8(z), and the physical matter density Ωm h
2. We obtain robust measurements by including a polynomial as the model for the systematic errors, and find it works very well against the systematic effects, e.g. ones induced by stars and seeing. We provide accurate measurements {D
A
(0.59)r
s,fid/r
s
, H(0.59)r
s
/r
s,fid, f(0.59)σ8(0.59), Ωm h
2} = {1427 ± 26 Mpc, 97.3 ± 3.3 km s−1 Mpc−1, 0.488 ± 0.060, 0.135 ± 0.016}, where r
s
is the comoving sound horizon at the drag epoch and r
s,fid = 147.66 Mpc is the sound scale of the fiducial cosmology used in this study. The parameters which are not well constrained by our galaxy clustering analysis are marginalized over with wide flat priors. Since no priors from other data sets, e.g. cosmic microwave background (CMB), are adopted and no dark energy models are assumed, our results from BOSS CMASS galaxy clustering alone may be combined with other data sets, i.e. CMB, SNe, lensing or other galaxy clustering data to constrain the parameters of a given cosmological model. The uncertainty on the dark energy equation of state parameter, w, from CMB+CMASS is about 8 per cent. The uncertainty on the curvature fraction, Ω
k
, is 0.3 per cent. We do not find deviation from flat ΛCDM.
This Voyage 2050 paper highlights the unique science opportunities using spectral distortions of the cosmic microwave background (CMB). CMB spectral distortions probe many processes throughout the ...history of the Universe, delivering novel information that complements past, present and future efforts with CMB anisotropy and large-scale structure studies. Precision spectroscopy, possible with existing technology, would not only provide key tests for processes expected within the cosmological standard model but also open an enormous discovery space to new physics. This offers unique scientific opportunities for furthering our understanding of inflation, recombination, reionization and structure formation as well as dark matter and particle physics. A dedicated experimental approach could open this new window to the early Universe in the decades to come, allowing us to turn the long-standing upper distortion limits obtained with
COBE
/FIRAS some 25 years ago into clear detections of the expected standard distortion signals and also challenge our current understanding of the laws of nature.
Planck 2018 results Aghanim, N.; Akrami, Y.; Aumont, J. ...
Astronomy and astrophysics (Berlin),
09/2020, Letnik:
641
Journal Article
Recenzirano
Odprti dostop
We present cosmological parameter results from the final full-mission
Planck
measurements of the cosmic microwave background (CMB) anisotropies, combining information from the temperature and ...polarization maps and the lensing reconstruction. Compared to the 2015 results, improved measurements of large-scale polarization allow the reionization optical depth to be measured with higher precision, leading to significant gains in the precision of other correlated parameters. Improved modelling of the small-scale polarization leads to more robust constraints on many parameters, with residual modelling uncertainties estimated to affect them only at the 0.5
σ
level. We find good consistency with the standard spatially-flat 6-parameter ΛCDM cosmology having a power-law spectrum of adiabatic scalar perturbations (denoted “base ΛCDM” in this paper), from polarization, temperature, and lensing, separately and in combination. A combined analysis gives dark matter density Ω
c
h
2
= 0.120 ± 0.001, baryon density Ω
b
h
2
= 0.0224 ± 0.0001, scalar spectral index
n
s
= 0.965 ± 0.004, and optical depth
τ
= 0.054 ± 0.007 (in this abstract we quote 68% confidence regions on measured parameters and 95% on upper limits). The angular acoustic scale is measured to 0.03% precision, with 100
θ
*
= 1.0411 ± 0.0003. These results are only weakly dependent on the cosmological model and remain stable, with somewhat increased errors, in many commonly considered extensions. Assuming the base-ΛCDM cosmology, the inferred (model-dependent) late-Universe parameters are: Hubble constant
H
0
= (67.4 ± 0.5) km s
−1
Mpc
−1
; matter density parameter Ω
m
= 0.315 ± 0.007; and matter fluctuation amplitude
σ
8
= 0.811 ± 0.006. We find no compelling evidence for extensions to the base-ΛCDM model. Combining with baryon acoustic oscillation (BAO) measurements (and considering single-parameter extensions) we constrain the effective extra relativistic degrees of freedom to be
N
eff
= 2.99 ± 0.17, in agreement with the Standard Model prediction
N
eff
= 3.046, and find that the neutrino mass is tightly constrained to ∑
m
ν
< 0.12 eV. The CMB spectra continue to prefer higher lensing amplitudes than predicted in base ΛCDM at over 2
σ
, which pulls some parameters that affect the lensing amplitude away from the ΛCDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data. The joint constraint with BAO measurements on spatial curvature is consistent with a flat universe, Ω
K
= 0.001 ± 0.002. Also combining with Type Ia supernovae (SNe), the dark-energy equation of state parameter is measured to be
w
0
= −1.03 ± 0.03, consistent with a cosmological constant. We find no evidence for deviations from a purely power-law primordial spectrum, and combining with data from BAO, BICEP2, and Keck Array data, we place a limit on the tensor-to-scalar ratio
r
0.002
< 0.06. Standard big-bang nucleosynthesis predictions for the helium and deuterium abundances for the base-ΛCDM cosmology are in excellent agreement with observations. The
Planck
base-ΛCDM results are in good agreement with BAO, SNe, and some galaxy lensing observations, but in slight tension with the Dark Energy Survey’s combined-probe results including galaxy clustering (which prefers lower fluctuation amplitudes or matter density parameters), and in significant, 3.6
σ
, tension with local measurements of the Hubble constant (which prefer a higher value). Simple model extensions that can partially resolve these tensions are not favoured by the
Planck
data.
We have observed the supernova remnant 3C 396 in the microwave region using the Parkes 64-m telescope. Observations have been made at 8.4, 13.5, and 18.6 GHz and in polarization at 21.5 GHz. We have ...used data from several other observatories, including previously unpublished observations performed by the Green Bank Telescope at 31.2 GHz, to investigate the nature of the microwave emission of 3C 396. Results show a spectral energy distribution dominated by a single component power-law emission with α = (−0.364 ± 0.017). Data do not favour the presence of anomalous microwave emission coming from the source. Polarized emission at 21.5 GHz is consistent with synchrotron-dominated emission. We present microwave maps and correlate them with infrared (IR) maps in order to characterize the interplay between thermal dust and microwave emission. IR versus microwave TT plots reveal poor correlation between mid-IR and microwave emission from the core of the source. On the other hand, a correlation is detected in the tail emission of the outer shell of 3C 396, which could be ascribed to Galactic contamination.
In this paper, we present Q-U-I JOint Tenerife Experiment (QUIJOTE) 10–20 GHz observations (194 h in total over ≈250 deg2) in intensity and polarisation of G159.6-18.5, one of the most widely studied ...regions harbouring anomalous microwave emission (AME). By combining with other publicly available intensity data, we achieve the most precise spectrum of the AME measured to date in an individual region, with 13 independent data points between 10 and 50 GHz being dominated by this emission. The four QUIJOTE data points provide the first independent confirmation of the downturn of the AME spectrum at low frequencies, initially unveiled by the COSMOlogical Structures On Medium Angular Scales experiment in this region. Our polarisation maps, which have an angular resolution of ≈1° and a sensitivity of ≈ 25 μK beam−1, are consistent with zero polarisation. We obtain upper limits on the polarisation fraction of Π < 6.3 and <2.8 per cent (95 per cent C.L.), respectively, at 12 and 18 GHz (ΠAME < 10.1 and <3.4 per cent with respect to the residual AME intensity), a frequency range where no AME polarisation observations have been reported to date. The combination of these constraints with those from other experiments confirm that all the magnetic dust models based on single-domain grains, and most of those considering randomly oriented magnetic inclusions, predict higher polarisation levels than is observed towards regions with AME. Also, neither of the two considered models of electric dipole emission seems to be compatible with all the observations together. More stringent constraints of the AME polarisation at 10–40 GHz are necessary to disentangle between different models, to which future QUIJOTE data will contribute.
We present Q-U-I JOint TEnerife (QUIJOTE) intensity and polarisation maps at 10-20 GHz covering a region along the Galactic plane 24... l ... 45..., |b| ... 8... These maps result from 210 h of data, ...have a sensitivity in polarisation of ...40 ...K beam super( -1) and an angular resolution of ...1... Our intensity data are crucial to confirm the presence of anomalous microwave emission (AME) towards the two molecular complexes W43 (22...) and W47 (8...). We also detect at high significance (6...) AME associated with W44, the first clear detection of this emission towards a supernova remnant. The new QUIJOTE polarisation data, in combination with Wilkinson Microwave Anisotropy Probe (WMAP), are essential to (i) determine the spectral index of the synchrotron emission in W44, ... = -0.62 plus or minus 0.03, in good agreement with the value inferred from the intensity spectrum once a free-free component is included in the fit; (ii) trace the change in the polarisation angle associated with Faraday rotation in the direction of W44 with rotation measure -404 plus or minus 49 rad m super( -2) and (iii) set upper limits on the polarisation of W43 of ... < 0.39 per cent (95 per cent C.L.) from QUIJOTE 17 GHz, and <0.22 per cent from WMAP 41 GHz data, which are the most stringent constraints ever obtained on the polarisation fraction of the AME. For typical physical conditions (grain temperature and magnetic field strengths), and in the case of perfect alignment between the grains and the magnetic field, the models of electric or magnetic dipole emissions predict higher polarisation fractions. (ProQuest: ... denotes formulae/symbols omitted.)
Planck 2015 results Ade, P A R; Aumont, J; Baccigalupi, C ...
Astronomy and astrophysics (Berlin),
10/2016, Letnik:
594
Journal Article
Recenzirano
Odprti dostop
We present the current accounting of systematic effect uncertainties for the Low Frequency Instrument (LFI) that are relevant to the 2015 release of the Planck cosmological results, showing the ...robustness and consistency of our data set, especially for polarization analysis. We use two complementary approaches: (i) simulations based on measured data and physical models of the known systematic effects; and (ii) analysis of difference maps containing the same sky signal ("null-maps"). The LFI temperature data are limited by instrumental noise. At large angular scales the systematic effects are below the cosmic microwave background (CMB) temperature power spectrum by several orders of magnitude. In polarization the systematic uncertainties are dominated by calibration uncertainties and compete with the CMB E-modes in the multipole range 10-20. Based on our model of all known systematic effects, we show that these effects introduce a slight bias of around 0.2sigma on the reionization optical depth derived from the 70GHz EE spectrum using the 30 and 353GHz channels as foreground templates. At 30GHz the systematic effects are smaller than the Galactic foreground at all scales in temperature and polarization, which allows us to consider this channel as a reliable template of synchrotron emission. We assess the residual uncertainties due to LFI effects on CMB maps and power spectra after component separation and show that these effects are smaller than the CMB amplitude at all scales. We also assess the impact on non-Gaussianity studies and find it to be negligible. Some residuals still appear in null maps from particular sky survey pairs, particularly at 30 GHz, suggesting possible straylight contamination due to an imperfect knowledge of the beam far sidelobes.
Planck intermediate results Akrami, Y.; Andersen, K. J.; Baccigalupi, C. ...
Astronomy and astrophysics (Berlin),
11/2020, Letnik:
643
Journal Article
Recenzirano
Odprti dostop
We present the
NPIPE
processing pipeline, which produces calibrated frequency maps in temperature and polarization from data from the
Planck
Low Frequency Instrument (LFI) and High Frequency ...Instrument (HFI) using high-performance computers.
NPIPE
represents a natural evolution of previous
Planck
analysis efforts, and combines some of the most powerful features of the separate LFI and HFI analysis pipelines. For example, following the LFI 2018 processing procedure,
NPIPE
uses foreground polarization priors during the calibration stage in order to break scanning-induced degeneracies. Similarly,
NPIPE
employs the HFI 2018 time-domain processing methodology to correct for bandpass mismatch at all frequencies. In addition,
NPIPE
introduces several improvements, including, but not limited to: inclusion of the 8% of data collected during repointing manoeuvres; smoothing of the LFI reference load data streams; in-flight estimation of detector polarization parameters; and construction of maximally independent detector-set split maps. For component-separation purposes, important improvements include: maps that retain the CMB Solar dipole, allowing for high-precision relative calibration in higher-level analyses; well-defined single-detector maps, allowing for robust CO extraction; and HFI temperature maps between 217 and 857 GHz that are binned into 0′.9 pixels (
N
side
= 4096), ensuring that the full angular information in the data is represented in the maps even at the highest
Planck
resolutions. The net effect of these improvements is lower levels of noise and systematics in both frequency and component maps at essentially all angular scales, as well as notably improved internal consistency between the various frequency channels. Based on the
NPIPE
maps, we present the first estimate of the Solar dipole determined through component separation across all nine
Planck
frequencies. The amplitude is (3366.6 ± 2.7)
μ
K, consistent with, albeit slightly higher than, earlier estimates. From the large-scale polarization data, we derive an updated estimate of the optical depth of reionization of
τ
= 0.051 ± 0.006, which appears robust with respect to data and sky cuts. There are 600 complete signal, noise and systematics simulations of the full-frequency and detector-set maps. As a
Planck
first, these simulations include full time-domain processing of the beam-convolved CMB anisotropies. The release of
NPIPE
maps and simulations is accompanied with a complete suite of raw and processed time-ordered data and the software, scripts, auxiliary data, and parameter files needed to improve further on the analysis and to run matching simulations.
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