PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013
as a large-class mission for investigating within the framework of the ESA Cosmic Vision
program a set of important scientific questions that require high resolution, high sensitivity, full-sky
observations of the sky emission
at wavelengths ranging from millimeter-wave to the far-infrared.
PRISM's main objective is to explore the distant universe, probing cosmic
history from very early times until now as well as the structures, distribution of
matter, and velocity flows throughout our Hubble volume. PRISM will
survey the full sky in a large number of frequency bands in both
intensity and polarization and will measure the absolute spectrum of sky emission more than
three orders of magnitude better than COBE FIRAS. The data obtained will allow us
to precisely measure the absolute sky brightness and polarization of all the components of the
sky emission in the observed frequency range,
separating the primordial and extragalactic components cleanly from the galactic and zodiacal light emissions.
The aim of this Extended White Paper is to provide a more detailed overview of the highlights
of the new science that will be made possible by PRISM, which include: (1) the ultimate
galaxy cluster survey using the Sunyaev-Zeldovich (SZ) effect, detecting approximately 106
clusters extending to large redshift, including a characterization of the gas temperature of
the brightest ones (through the relativistic corrections to the classic SZ template) as well
as a peculiar velocity survey using the kinetic SZ effect that comprises our entire Hubble
volume; (2) a detailed characterization of the properties and evolution of dusty galaxies, where
the most of the star formation in the universe took place, the faintest population of which
constitute the diffuse CIB (Cosmic Infrared Background); (3) a characterization of the B modes from
primordial gravity waves generated during inflation and from gravitational lensing, as well
as the ultimate search for primordial non-Gaussianity using CMB polarization, which is less
contaminated by foregrounds on small scales than the temperature anisotropies; (4) a search
for distortions from a perfect blackbody spectrum, which include some nearly certain signals
and others that are more speculative but more informative; and (5) a study of the role of the
magnetic field in star formation and its interaction with other components of the
interstellar medium of our Galaxy. These are but a few of the highlights presented here
along with a description of the proposed instrument.