Growth of Galaxies and Black Holes over Cosmic Time

Most of the star formation and black hole growth in the Universe has taken place under cover of dust. PRIMA’s far-IR instrumentation penetrates dust to access spectral features that uniquely measure both star formation and black hole accretion in large samples of galaxies across cosmic time.

The Rise of Metals and Dust

Optical abundance measurements suffer extinction and temperature uncertainties. PRIMA will measure the absolute and relative abundances of heavy elements where they are formed, deep in the hearts of galaxies. PRIMA’s spectrometers can see through dust and are immune to gas temperature, providing direct access to metal enrichment from cosmic noon to today.

Cosmic Ecosystems

Through gas accretion and powerful outflows, galaxies are intimately connected to the cosmic web. PRIMA’s sensitivity to the physical conditions of the gas and dust in and around galaxies will unlock the energetics and dynamics of all steps in the galactic baryon cycle. Deep imaging and spectroscopy will uncover accreting gas and cool dense winds invisible to other observatories.

Revealing the Role of Cosmic Magnetic Fields

Magnetic fields are believed to affect the rate, efficiency, and mass function of star formation. PRIMA’s polarimeter channels will map magnetic fields in the Magellanic clouds and other nearby galaxies. With resolution reaching down to protostellar core scales while spanning the full extent of these galaxies, PRIMA will quantify the influence of magnetic fields in star formation and galaxy evolution.

Star Formation in the Time Domain
Protostellar growth is episodic. PRIMA’s sensitive imager will provide time-resolved, far-IR measurements of the total mass accretion rate in 1000 protostars across the stellar mass range. This will, for the first time, reveal the dominant stellar accretion modes from low- to high-mass stars, uniquely constraining star formation theory.

Exoplanets and Brown Dwarf Atmospheres
The study of exoplanet and brown dwarf atmospheres put our solar system in context. PRIMA far-IR spectroscopy of the atmospheres of close-in, giant exoplanets and isolated brown dwarf will yield further insights to their formation and evolution.

Planet Formation
Planet formation theory is fundamentally limited by major uncertainties on the total gas mass and the mass and disposition of water in planet-forming disks. PRIMA offers full far-IR spectral coverage at high sensitivity to produce complete spectra of hundreds to thousands of planet-forming disks. These will measure the mass and disposition of gas and water vapor and ice reservoirs across the stellar mass and age ranges, testing theories of planet formation.

Origins of Earth’s Water

Water is essential for life as we know it. The origin of Earth’s water may have been integral to its formation, or it may have been delivered post-formation via comet impacts. PRIMA spectroscopy of comets and asteroids will discriminate among these theories as well as those describing planet formation in general via isotopic composition analyses of bodies throughout the solar system.

Discovery Potential

A cryogenic observatory for the far-IR offers a gain in sensitivity comparable to viewing a dark night sky at noon. Every aspect of PRIMA is designed to maximize sensitivity and efficiency, resulting in a Probe-class observatory for the entire community that covers the rich, but poorly explored spectral band between the mid-infrared and submillimeter.