JEM-EUSO Science

Abstract

The Extreme Universe Space Observatory (EUSO) to be accommodated in the Japanese Experiment Module (JEM) of the International Space Station (ISS), JEM-EUSO, is designed to discover the origin of ultrahigh energy cosmic rays by observing extremely energetic extensive airshowers from space. The JEM-EUSO design is based on a wide field of view (60 •) refractor with an ultrafast 0.3M pixel UV camera that records the extensive airshower fluorescence and backscattered cherenkov. The main science goal of JEM-EUSO is to accumulate significantly higher number of events than available from ground-based observatories at the highest energies. The ISS orbit guarantees full sky coverage and its altitude provides the ability to monitor two orders of magnitude more atmosphere when compared to fluorescence telescopes on the ground. The large number of observed extremely energetic events will provide a sky map of the relatively nearby sources. The increase in statistics will also provide a measurement of the spectral shape around the GZK feature, which may have a recovery depending on the maximum energy of UHECR sources. Extremely energetic neutrinos may also be observed as well as fast atmospheric phenomena and meteoroid emission in the UV. JEM-EUSO will also test physics beyond the standard model by searching for the decay products of super-heavy dark matter and tracks produced by strangelets.

“Lomonosov” Satellite—Space Observatory to Study Extreme Phenomena in Space

“…It was demonstrated that if the detected luminosity of the hotspot is attributed to a physical effect and not a statistical fluctuation, the KLYPVE and JEM-EUSO experiments would need to collect approximately 300 events with energies above 57 EeV over the whole celestial sphere in order to detect the hotspot at the 5σ confidence level with 68% probability. It was estimated by Olinto et al (2015) that with the annual exposure ∼ 5 × 10 4 km 2 sr above ∼ 60 EeV, JEM-EUSO will collect 429 events/yr, or about 2,145 events in 5 years. KLYPVE will have the annual exposure ∼ 1.2 × 10 4 km 2 sr above 50 EeV (Panasyuk et al 2015;Sakaki et al 2015) and thus will be able to detect more than 100 events every year of operation, and more than 600 events during its planned lifetime.…”

The EUSO-BALLOON mission

“…JEM-EUSO is designed to observe ultra high-energy cosmic rays (UHECRs) by looking downward to the Earth's atmosphere from the ISS, observing the UV fluorescence light of UHECR-induced Extensive Air Showers (EAS). This conference includes a number of detailed articles on JEM-EUSO, notably its status [1], the science case [2]; for an overview of the JEM-EUSO instruments see [3].…”

Mini-EUSO flight software and operations on ISS

“…At such energies, the flux is as low as 1 particle/km 2 /century and the effective area that can be observed by a detector is a key feature. The JEM-EUSO Collaboration aims to detect the UV light produced by EECR-induced atmospheric showers from the vantage point of low Earth orbit, thereby largely increasing the effective detector volume [1,2]. In order to lay the groundwork for such unprecedented observations, the JEM-EUSO collaboration has successfully initiated several pathfinder experiments.…”