The Polarization Signature of Local Bulk Flows

Abstract

A large peculiar velocity of the intergalactic medium produces a Doppler shift of the cosmic microwave background with a frequency-dependent quadrupole term. This quadrupole will act as a source for polarization of the cosmic microwave background, creating a large-scale polarization anisotropy if the bulk flow is local and coherent on large scales. In the case where we are near the center of the moving region, the polarization signal is a pure quadrupole. We show that the signal is small, but detectable with future experiments for bulk flows as large as some recent reports.

5 pages, 3 figures. Accepted by ApJ

References in corpus (4)

• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
• Supernova Constraints and Systematic Uncertainties from the First 3 Years of the Supernova Legacy Survey
• Studying the Peculiar Velocity Bulk Flow in a Sparse Survey of Type-Ia SNe
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Cited by in corpus (4)

• Detecting the polarization induced by scattering of the microwave background quadrupole in galaxy clusters
• Kinetic Sunyaev Zeldovich effect in an anisotropic CMB model: measuring low multipoles of the CMB at higher redshifts using intensity and polarization spectral distortions
• Cosmology from the kinetic polarized Sunyaev Zel'dovich effect
• E and B modes of the CMB y-type distortions: polarised kinetic Sunyaev-Zeldovich effect from the reionisation and post-reionisation eras