PRISM (Polarized Radiation Imaging and Spectroscopy Mission): An Extended White Paper (1310.1554v3)

Abstract: 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 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

• The paper presents a comprehensive mission proposal employing full-sky, multi-frequency observations to address key astrophysical and cosmological questions.
• It utilizes innovative techniques, including the Sunyaev-Zeldovich effect and refined CMB polarization measurements, to detect around one million galaxy clusters and primordial signals.
• The paper highlights advanced instrumentation designed to separate complex emission components, significantly enhancing our understanding of cosmic evolution and early universe phenomena.

Overview of the PRISM (Polarized Radiation Imaging and Spectroscopy Mission) Paper

The paper "PRISM (Polarized Radiation Imaging and Spectroscopy Mission): An Extended White Paper" presents a comprehensive proposal for a large-class mission aimed at exploring a wide range of fundamental questions in astrophysics and cosmology. This proposal was submitted as part of the European Space Agency's (ESA) Cosmic Vision program, which seeks to address significant scientific themes through high-resolution, high-sensitivity, full-sky observations across a broad spectrum of wavelengths, from millimeter-wave to far-infrared.

Scientific Goals and Observational Objectives

The PRISM mission is designed to provide unprecedented insight into the universe's history and structure by surveying the entire sky in multiple frequency bands, analyzing both intensity and polarization. The mission's principal scientific objectives are:

1. Galaxy Cluster Survey: Utilizing the Sunyaev-Zeldovich (SZ) effect, the mission aims to detect approximately $10^6$ galaxy clusters, including those at significant redshifts, and characterize the gas temperature in the brightest clusters. This data will also facilitate a peculiar velocity survey leveraging the kinetic SZ effect across the Hubble volume.
2. Dusty Galaxies and Cosmic Infrared Background (CIB): PRISM will investigate the properties and evolution of dusty galaxies, which are pivotal in understanding star formation throughout cosmic history. This investigation includes the paper of faint galaxy populations that constitute the diffuse CIB.
3. Primordial B-modes and Non-Gaussianity in Cosmic Microwave Background (CMB): By characterizing the B modes from primordial gravitational waves and gravitational lensing, PRISM seeks to manage the less foreground-contaminated CMB polarization on small scales, enabling a refined search for primordial non-Gaussianity.
4. Spectral Distortions in CMB: The mission will hunt for both anticipated and speculative signals indicating deviations from a perfect blackbody spectrum, offering new insights into the thermal history of the universe.
5. Magnetic Fields and Star Formation: A critical aspect of the mission is to paper how magnetic fields influence star formation and interact with other interstellar medium components within the Milky Way.

Methodology and Instrumentation

PRISM intends to achieve its scientific goals through advanced instruments capable of measuring the absolute spectrum of sky emission with sensitivity exceeding that of COBE FIRAS by more than three orders of magnitude. This capability will allow for precise separation of primordial and extragalactic components from the Galactic and zodiacal emissions.

The mission's observational strategy includes a legacy archive designed to serve as a comprehensive scientific resource for future research. It will complement and extend the capabilities of other recent and upcoming cosmological observations.

Implications and Future Directions

The research facilitated by the PRISM mission could significantly enhance our understanding of cosmic evolution, structure formation, and the underlying physics governing these processes. The ability to discern primordial gravitational waves and non-Gaussian features could provide crucial evidence for cosmic inflation theories and refine models of the early universe.

Further development and deployment of the mission would likely necessitate close collaboration with ongoing and planned observational initiatives, maximizing the scientific return on investment. The PRISM mission exemplifies how large-scale, sophisticated observational strategies are essential to tackling some of the most profound questions in modern cosmology.

In conclusion, the PRISM Extended White Paper lays out a compelling scientific case for a mission that promises to advance our knowledge across several key areas of astrophysical research, expanding our understanding of the universe's earliest moments to its current vast structures.