Polarization Maps at CMB Frequencies from Planck

Research and Scientific Support Department of the European Space Agency, ESTEC, PO Box 299, 2200AG Noordwijk, The Netherlands

Abstract

Planck is designed to image the anisotropies of the Cosmic Microwave Background (CMB) over the whole sky, with unprecedented sensitivity (ΔT/T ~ 2 × 10^-6) and angular resolution (~5 arcmin). Planck will provide a major source of information relevant to several cosmological and astrophysical issues, such as testing theories of the early universe and the origin of cosmic structure. The ability to measure to high accuracy the angular power spectrum of the CMB fluctuations will allow the determination of fundamental cosmological parameters with an uncertainty of order a few percent. In addition to the main cosmological goals of the mission, the Planck sky survey will be used to study in detail the very sources of emission which “contaminate” the signal due to the CMB. This will result in a wealth of information on the properties of extragalactic sources, and on the dust and gas in our own galaxy. One specific notable result will be the measurement of the polarized emission from our own Galaxy. The ability of Planck to measure polarization across a wide frequency range (30–350 GHz), with high precision and accuracy, and over the whole sky, will provide unique insight into the properties of the interstellar medium. An overview is presented of the Planck mission, its scientific objectives, the key elements of its technical design, and its current status.