POEMMA: Probe Of Extreme Multi-Messenger Astrophysics

Selected as a NASA Astrophysics probe study, the Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to identify the sources of ultra-high energy cosmic rays (UHECRs) and to observe cosmic neutrinos. POEMMA consists of two Schmidt telescopes each using a novel focal plane optimized to observe both the UV fluorescence signal from extensive air showers (EAS) and the optical Cherenkov signals from EAS. The POEMMA telescopes will fly in a loose formation at 525 km altitude and employ two different observing modes. In UHECR stereo mode, POEMMA will measure the spectrum, composition, and full-sky distribution of the UHECRs above 30 EeV to identify and study the most energetic cosmic accelerators in the universe. In neutrino mode, POEMMA will be sensitive to cosmic tau neutrinos above 20 PeV by observing the upward-moving EAS induced from tau neutrino interactions in the Earth. POEMMA is designed to quickly re-orient to a Target-of-Opportunity (ToO) neutrino mode to view transient astrophysical sources with unique sensitivity. In this talk, the science goals, instrument & mission designs, and simulated UHECR and neutrino measurement capabilities of POEMMA will be presented.