Abstract Recent measurements of Galactic polarized dust emission have found a nonzero TB signal, a correlation between the total intensity and the B -mode polarization component. We present evidence ...that this parity-odd signal is driven by the relative geometry of the magnetic field and the filamentary interstellar medium in projection. Using neutral hydrogen morphology and Planck polarization data, we find that the angle between intensity structures and the plane-of-sky magnetic field orientation is predictive of the signs of Galactic TB and EB . Our results suggest that magnetically misaligned filamentary dust structures introduce nonzero TB and EB correlations in the dust polarization, and that the intrinsic dust EB can be predicted from measurements of dust TB and TE over the same sky mask. We predict correlations between TE , TB , EB , and EE / BB , and confirm our predictions using synthetic dust polarization maps from magnetohydrodynamic simulations. We introduce and measure a scale-dependent effective magnetic misalignment angle, ψ ℓ dust ∼ 5 ° for 100 ≲ ℓ ≲ 500, and predict a positive intrinsic dust EB with amplitude D ℓ EB ≲ 2.5 μ K CMB 2 for the same multipole range at 353 GHz over our sky mask. Both the sign and amplitude of the Galactic EB signal can change with the sky area considered. Our results imply that searches for parity violation in the cosmic microwave background must account for the nonzero Galactic EB and TB signals, necessitating revision of existing analyses of the evidence for cosmic birefringence.
Abstract
Cross-correlations between galaxy weak lensing (WL) and cosmic microwave background (CMB) lensing are powerful tools to probe matter fluctuations at intermediate redshifts and to detect ...residual systematics in either probe. In this paper, we study the cross-correlation of galaxy WL from the Hyper Suprime-Cam Subaru Strategic Program (HSC) first data release and CMB lensing from the final Planck data release, for HSC source galaxies at 0.3 ≤
z
≤ 1.5. HSC is the deepest Stage-III galaxy WL survey, and provides a great opportunity to study the high-redshift universe. It also presents new challenges related to its exceptionally high source density, such as source blending. The cross-correlation signal is measured at a significance level of 3.1
σ
. The amplitude of our best-fit model with respect to the best-fit 2018 Planck cosmology is
A
= 0.81 ± 0.25, consistent with
A
= 1. Our result is also consistent with previous CMB lensing and galaxy WL cross-correlation studies using different surveys. We perform tests with respect to the WL
B
-modes, the point-spread-function, photometric redshift errors, and thermal Sunyaev–Zel’dovich leakage, and find no significant evidence of residual systematics.
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