Revised estimates of CMB <i>B</i>-mode polarization induced by patchy reionization

Roy, Anirban; Kulkarni, Girish; Meerburg, P. Daniel; Challinor, A.; Baccigalupi, C.; Lapi, A.; Haehnelt, Martin G.

doi:10.1088/1475-7516/2021/01/003

Cited by 19 publications

(10 citation statements)

References 129 publications

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“…In order to break degeneracies between parameters, detect systematics, and allow a fruitful analysis of available data sets, a consistent analysis of the different observables of reionisation seems to be a promising avenue. Indeed, several works have already demonstrated the potential offered by a combined analysis of astrophysical and CMB data (e.g., Millea & Bouchet 2018;Qin et al 2020;Chatterjee et al 2021;Baxter et al 2021;Sato-Polito et al 2021;La Plante et al 2022), 21 cm andCMB data (e.g., Tashiro et al 2011;Alvarez 2016;Ma et al 2018;Hotinli & Johnson 2022;La Plante et al 2020;Billings et al 2021;Choudhury et al 2021;Ahn & Shapiro 2021;Bégin et al 2022), or different types of CMB data (e.g., Planck Collaboration XLVII 2016; Alvarez et al 2021;Namikawa et al 2021;Paul et al 2021;Roy et al 2021).…”

Section: Cosmological Constraintsmentioning

confidence: 99%

Retrieving cosmological information from small-scale CMB foregrounds

Gorce

Douspis

Salvati

2022

A&A

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Recent results of ground-based telescopes, giving high-quality measurements of the cosmic microwave background (CMB) temperature power spectrum on small scales (below 1 deg) motivate the need for an accurate model of foregrounds, which dominate the primary signal at these multipoles. In a previous work, we have shown that cosmological information could be retrieved from the power spectrum of the thermal Sunyaev Zel’dovich (SZ) effect. In this work, we introduce a physically motivated model of the Epoch of Reionisation in the cosmological analysis of CMB data, which is coherent on all scales. In particular, at high multipoles, the power spectrum of the kinetic SZ (kSZ) effect is inferred from a set of cosmological and reionisation parameters by a machine-learning algorithm. First including an asymmetric parameterisation of the reionisation history in the Planck 2018 data analysis, we retrieve a value of the Thomson optical depth consistent with previous results, but stemming from a completely different history of reionisation in which the first luminous sources light up as early as z = 15. Considering the latest small-scale data from the South Pole telescope (SPT) and letting the cosmology free to vary, we find that including the new cosmology-dependent tSZ and kSZ spectra helps tighten the constraints on their amplitudes by breaking their degeneracy. We report a 5σ measurement of the kSZ signal at ℓ = 3000, D3000kSZ = 3.4−0.3+0.5 μK2 at the 68% confidence level (C.L.), marginalised over cosmology, as well as an upper limit on the patchy signal from reionisation D3000pkSZ < 1.6 μK2 (95% C.L.). Additionally, we find that the SPT data favour slightly earlier reionisation scenarios than Planck, leading to τ = 0.062−0.015+0.012 and a reionisation midpoint zre = 7.9−1.3+1.1 (68% C.L.), which is in line with constraints from high-redshift quasars and galaxies.

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Section: Cosmological Constraintsmentioning

confidence: 99%

Retrieving cosmological information from small-scale CMB foregrounds

Gorce

Douspis

Salvati

2022

A&A

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“…Currently it is unclear what will set the fundamental B-mode floor and thus the fundamental limit on the bispectrum SNR. It is likely that this floor will arise from either emission-angle effects [35], post-Born lensing effects [36], B-modes from reionization [57][58][59][60] or limitations in delensing techniques [61] which could limit the detectability of the intrinsic bispectrum to SNR∼ 20-100. Assuming this limits delensing to 99% we plot the cosmic variance limited SNR in Figure 2.…”

Section: Detectabilitymentioning

confidence: 99%

The parity-odd Intrinsic Bispectrum

Coulton

2021

Preprint

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At linear order the only expected source of a curl-like, B mode, polarization pattern in the cosmic microwave background (CMB) is primordial gravitational waves. At second-order B modes are also produced from purely scalar, density, initial conditions. Unlike B modes from primordial gravitational waves, these B modes are expected to be non-Gaussian and not independent from the temperature and gradient-like polarization, E mode, CMB anisotropies. We find that the three point function between a second-order B mode and two first-order T/E modes is a powerful probe of second-order B modes and should be detectable by upcoming CMB experiments. We focus on the contribution to the three point function arising from non-linear evolution and scattering processes before the end of recombination as this provides new information on the universe at z > 1000. We find that this contribution can be separated from the other contributions and is measurable at ∼ 2.5σ by CMB experiments with noise levels of ∼ 1µKarcmin and delensing efficiencies ≥ 90%, such as the proposed PICO satellite. We show that approximately half of the total signal arises from non-linearly induced vector and tensor metric perturbations, as evaluated in the Newtonian gauge. This bispectrum is a unique probe of these perturbations in the CMB, as their contribution to the power spectrum is suppressed. An important feature of this bispectrum is that the detectability will increase with decreasing experimental noise, in the absence of primordial B modes, provided that delensing efficiencies improve in parallel.

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“…The small scale temperature and polarization anisotropies in CMB are suppressed by a factor of e −τ ( n) due to effects of "patchy screening", where τ ( n) is the direction-dependent optical depth Gluscevic et al 2013). This can be probed by the reconstruction of optical depth field Gluscevic et al 2013;Namikawa 2018;Roy et al 2018Roy et al , 2021Guzman & Meyers 2021). Similar to but smaller than the reionization process, galaxies and galaxy clusters at low redshift contribute to these optical depth fluctuations and provide a probe of the distribution of free electrons inside such halos.…”

Section: Introductionmentioning

confidence: 99%

Probing the circumgalactic medium with CMB polarization statistical anisotropy

Roy¹,

Engelen²,

Gluscevic³

et al. 2022

Preprint

Self Cite

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As cosmic microwave background (CMB) photons traverse the Universe, anisotropies can be induced via Thomson scattering (proportional to the integrated electron density; optical depth) and inverse Compton scattering (proportional to the integrated electron pressure; thermal Sunyaev-Zel'dovich effect). Measurements of anisotropy in optical depth τ and Compton y parameter are imprinted by the galaxies and galaxy clusters and are thus sensitive to the thermodynamic properties of circumgalactic medium and intergalactic medium. We use an analytic halo model to predict the power spectrum of the optical depth (τ τ ), the cross-correlation between the optical depth and the Compton y parameter (τ y), as well as the cross-correlation between the optical depth and galaxy clustering (τ g), and compare this model to cosmological simulations. We constrain the optical depths of halos at z 3 using a technique originally devised to constrain patchy reionization at a much higher redshift range. The forecasted signal-to-noise ratio is 2.6, 8.5, and 13, respectively, for a CMB-S4-like experiment and a VRO-like optical survey. We show that a joint analysis of these probes can constrain the amplitude of the density profiles of halos to 6.5% and the pressure profile to 13%, marginalizing over the outer slope of the pressure profile. These constraints translate to astrophysical parameters related to the physics of galaxy evolution, such as the gas mass fraction, f g , which can be constrained to 5.3% uncertainty at z ∼ 0, assuming an underlying model for the shape of the density profile. The cross-correlations presented here are complementary to other CMB and galaxy cross-correlations since they do not require spectroscopic galaxy redshifts and are another example of how such correlations are a powerful probe of the astrophysics of galaxy evolution.

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Revised estimates of CMB B-mode polarization induced by patchy reionization

Cited by 19 publications

References 129 publications

Retrieving cosmological information from small-scale CMB foregrounds

Retrieving cosmological information from small-scale CMB foregrounds

The parity-odd Intrinsic Bispectrum

Probing the circumgalactic medium with CMB polarization statistical anisotropy

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