[Paper Review] PRISM (Polarized Radiation Imaging and Spectroscopy Mission): A White Paper on the Ultimate Polarimetric Spectro-Imaging of the Microwave and Far-Infrared Sky

PRISM Collaboration, Philippe André+102 more|arXiv (Cornell University)|Jun 10, 2013

Cosmology and Gravitation Theories12 references83 citations

TL;DR

PRISM is a proposed large-class space mission to conduct the ultimate all-sky survey in microwave to far-infrared wavelengths with full polarimetric and absolute spectroscopic capabilities. By combining a high-resolution polarimetric imager and a low-resolution spectrometer, PRISM will detect over 1 million galaxy clusters, map the cosmic infrared background with unprecedented sensitivity, and detect primordial gravitational waves from inflation, enabling transformative advances in cosmology and astrophysics.

ABSTRACT

PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in response to the Call for White Papers for the definition of the L2 and L3 Missions in the ESA Science Programme. PRISM would have two instruments: (1) an imager with a 3.5m mirror (cooled to 4K for high performance in the far-infrared---that is, in the Wien part of the CMB blackbody spectrum), and (2) an Fourier Transform Spectrometer (FTS) somewhat like the COBE FIRAS instrument but over three orders of magnitude more sensitive. Highlights of the new science (beyond the obvious target of B-modes from gravity waves generated during inflation) made possible by these two instruments working in tandem include: (1) the ultimate galaxy cluster survey gathering 10e6 clusters extending to large redshift and measuring their peculiar velocities and temperatures (through the kSZ effect and relativistic corrections to the classic y-distortion spectrum, respectively) (2) a detailed investigation into the nature of the cosmic infrared background (CIB) consisting of at present unresolved dusty high-z galaxies, where most of the star formation in the universe took place, (3) searching for distortions from the perfect CMB blackbody spectrum, which will probe a large number of otherwise inaccessible effects (e.g., energy release through decaying dark matter, the primordial power spectrum on very small scales where measurements today are impossible due to erasure from Silk damping and contamination from non-linear cascading of power from larger length scales). These are but a few of the highlights of the new science that will be made possible with PRISM.

Motivation & Objective

• To perform the most sensitive all-sky survey in the microwave to far-infrared spectrum with full polarimetric and absolute spectral resolution.
• To detect and characterize galaxy clusters up to redshift z > 2, enabling precise mapping of the large-scale velocity field and probing dark energy and structure formation.
• To resolve the cosmic infrared background (CIB) by detecting tens of thousands of star-forming and lensed galaxies up to z > 6, revealing the history of star formation and interstellar medium physics.
• To detect primordial B-mode polarization from inflationary gravitational waves with high sensitivity, testing fundamental models of the early universe.
• To provide a comprehensive, all-sky reference for future ground- and space-based missions such as ALMA, SKA, and CCAT by delivering deep, confusion-limited maps across key frequency bands.

Proposed method

• Utilize a 3.5 m cooled telescope (to ~4 K) for high angular resolution polarimetric imaging across microwave to far-infrared bands.
• Deploy a low-resolution spectrometer to compare the sky’s frequency spectrum to a nearly perfect blackbody reference, enabling absolute spectroscopy.
• Leverage the Sunyaev-Zeldovich (SZ) effect to detect galaxy clusters via spectral distortion in the CMB, with high sensitivity and angular resolution to extend cluster surveys beyond z = 2.
• Apply kinetic SZ effect measurements to infer cluster peculiar velocities, enabling full 3D mapping of the large-scale velocity field in the Hubble volume.
• Use high-resolution far-infrared imaging to detect and characterize dusty, star-forming galaxies, including strongly lensed and extreme starburst systems at high redshift.
• Combine data from PRISM with existing surveys (e.g., eROSITA, Euclid) for cross-calibration, improved cluster mass estimates, and stacked X-ray analysis of fainter structures.

Experimental results

Research questions

• RQ1 Can a space-based all-sky survey in intensity, polarization, and absolute spectrum detect all galaxy clusters with mass > 10^14 M☉ and a large fraction above 5×10^13 M☉, extending to z > 2?
• RQ2 To what extent can PRISM’s high-resolution polarimetry and absolute spectroscopy enable the detection of primordial B-mode polarization from inflationary gravitational waves?
• RQ3 How accurately can PRISM map the cosmic infrared background (CIB) and resolve the bolometric luminosity function and clustering of star-forming galaxies up to z > 6?
• RQ4 Can PRISM’s spectral and spatial resolution allow for the detection of relativistic corrections to the SZ effect, enabling direct measurement of intracluster gas temperature?
• RQ5 How will PRISM’s all-sky maps at confusion-limited sensitivity in multiple frequency bands complement ground-based interferometers like ALMA and future missions like SKA and CCAT?

Key findings

• PRISM will detect approximately 1 million galaxy clusters, including all clusters above 10^14 M☉ and a large fraction above 5×10^13 M☉, extending to redshifts beyond z = 2.
• The mission will measure the peculiar velocities of hundreds of thousands of clusters via the kinetic Sunyaev-Zeldovich effect, enabling a complete 3D mapping of the large-scale velocity field in the Hubble volume.
• PRISM will detect tens of thousands of strongly lensed, bright star-forming galaxies and hundreds of extreme starburst galaxies up to redshift z > 6, providing unique insights into high-redshift star formation and interstellar medium physics.
• The mission will achieve confusion-limited sensitivity across multiple frequency bands, enabling all-sky maps with sensitivity comparable to or better than Herschel, but covering the entire sky.
• PRISM will measure the spectral energy distribution (SED) of thousands of radio sources across a poorly explored sub-millimeter to millimeter frequency range, filling a critical observational gap.
• By combining with eROSITA and Euclid surveys, PRISM will enable cross-calibration of X-ray and SZ-based cluster cosmology, improve cluster mass and temperature estimates, and allow stacked X-ray analysis of fainter structures.