The JEM-EUSO Mission

TL;DR

The JEM-EUSO mission aims to study the origins and physics of extreme energy cosmic rays using a space-based telescope to detect UV photons from air showers, potentially revealing their sources and fundamental physics insights.

Contribution

This paper introduces the JEM-EUSO mission, a novel space-based observatory designed to detect ultra-high-energy cosmic rays with unprecedented exposure and resolution.

Findings

Designed to achieve over 1 million km^2 sr year exposure

Will map arrival directions of over 500 EECR events

Aims to identify cosmic ray sources and test fundamental physics

Abstract

The JEM-EUSO mission explores the origin of the extreme energy cosmic rays (EECRs) above 100 EeV and explores the limits of the fundamental physics through the observations of their arrival directions and energies. It is designed to achieve an exposure larger than 1 million km^2 sr year to open a new particle astronomy channel. This super-wide-field (60 degrees) telescope with a diameter of about 2.5 m looks down from space onto the night sky to detect near UV photons (330-400nm, both fluorescent and Cherenkov photons) emitted from the giant air showers produced by EECRs. The arrival direction map with more than five hundred events will tell us the origin of the EECRs and allow us to identify the nearest EECR sources with known astronomical objects. It will allow them to be examined in other astronomical channels. This is likely to lead to an understanding of the acceleration mechanisms, perhaps producing discoveries in astrophysics and/or fundamental physics. The comparison of the energy spectra among the spatially resolved individual sources will help to clarify the acceleration/emission mechanism, and also finally confirm the Greisen-Zatsepin-Kuz'min process for the validation of Lorentz invariance up to {\gamma}~10^{11}. Neutral components (neutrinos and gamma rays) can also be detected as well, if their fluxes are high enough. The JEM-EUSO mission is planned to be launched by a H2B rocket about JFY 2015-2016 and transferred to ISS by H2 Transfer Vehicle (HTV). It will be attached to the Exposed Facility external experiment platform of "KIBO".