Overview and First Results of EUSO-SPB2

TL;DR

EUSO-SPB2, launched in 2023, is a pioneering space-based observatory using fluorescence and Cherenkov telescopes on a balloon to detect ultra-high energy cosmic rays and neutrinos, aiming to advance multi-messenger astrophysics.

Contribution

This paper presents the first results and overview of the EUSO-SPB2 mission, a novel balloon-borne observatory for ultra-high energy cosmic ray and neutrino detection.

Findings

Initial optical background measurements obtained

Successful operation of fluorescence and Cherenkov telescopes

Data will inform future space-based multi-messenger observatories

Abstract

Observing ultra-high energy cosmic rays (UHECR) and very high energy (VHE) neutrinos from space is a promising way to measure their extremely low fluxes by significantly increasing the observed volume. The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2), the next, most advanced pathfinder for such a mission, was launched May 13th 2023 from Wanaka New Zealand. The pioneering EUSO-SPB2 payload flew a Fluorescence Telescope (FT) with a PMT camera pointed in nadir to record fluorescence light from cosmic ray extensive air shower (EAS) with energies above 1 EeV, and a Cherenkov telescope (CT) with a silicon photomultiplier focal surface for observing Cherenkov emission of cosmic ray EAS with energies above 1 PeV with an above-the-limb geometry and of PeV-scale EAS initiated by neutrino-sourced tau decay. As the CT is a novel instrument, optical background measurements for space neutrino observation are an important goal of the mission. Any data collected during the mission will influence and improve the development of a space-based multi-messenger observatory such as the Probe of Extreme Multi-Messenger Astrophysics (POEMMA). We present an overview of the EUSO-SPB2 mission and its science goals and summarize results as available, from the 2023 flight.