Voyage 2050 Spectro-Polarization Mission

Accurate microwave spectro-polarimetry offers a unique opportunity to perform a tomographic and dynamic census of the three-dimensional distribution of hot gas, velocity flows, early metals, dust, and mass distribution in the entire Hubble volume, as well as to exploit CMB temperature and polarisation anisotropies down to fundamental limits, and to track energy injection and absorption into the radiation background across cosmic times.

The proposed space mission will perform a combination of sensitive spectro-polarimetric observations of the microwave sky with three main instruments: two of them, a broad-band polarised imager and a moderate resolution spectro-imager, will be located at the focus of a 3.5m aperture telescope actively cooled to about 8K. They will be complemented by an absolutely-calibrated Fourier Transform Spectrometer observing at degree-scale angular resolution in the 10-2000 GHz frequency range.

Multifrequency maps of the microwave sky will be obtained in two observing modes: a survey mode to map the entire sky, and an observatory mode, accessible to the community at large, for deeper observations of selected fields of specific interest. All data will be publically released to the community after an initial proprietary period.

In addition to exceptional capability for cosmology and fundamental physics, the space mission will provide an unprecedented view of microwave emissions at sub-arcminute to few-arcminute angular resolution in hundreds of frequency channels, a data set of immense legacy value for many branches of astrophysics.