Presentation #108.58 in the session “Missions and Instruments (Poster)”.
The Lunar Occultation eXplorer (LOX) fills a long-standing astrophysical capability gap at MeV energies. LOX leverages the power of high-sensitivity and continuous all-sky monitoring to achieve its primary science goal: the first systematic population studies of thermonuclear supernova (type-Ia, SNeIa) using their emergent nuclear radiation. LOX will probe the fundamental nuclear processes that govern these “beacons of the Cosmos” by characterizing the temporal and spectral evolution of their emergent gamma-rays. LOX measurements of the radioactivity left behind in the wake of nuclear burning will reveal characteristic trends via population studies that individual detections cannot, further our understanding of the matter–energy life cycles within galaxies, and provide critical diagnostic evidence for the multiple evolutionary pathways responsible for this class of supernovae. LOX will directly test the assumption of SNeIa homogeneity by quantifying the diversity of thermonuclear scenarios and SNeIa progenitors, and ultimately provide additional context to open questions in cosmology (e.g., cosmic expansion history, dark energy) and astrophysics (e.g., details of the nucleosynthetic yields). The LOX implementation approach mitigates the challenges associated with increasingly complex space-based instrumentation. LOX will achieve its science goals with a simple, low-cost, cross-cutting implementation based on the Lunar Occultation Technique (LOT); implementation and operational simplicity are its hallmarks. LOX leverages the benign, well-characterized lunar environment to achieve transformational performance, including sensitivity, and employs a single-instrument payload consisting of an array of identical gamma-ray sensor modules. The instrument design and its single mode of operation leverage decades of heritage derived from planetary exploration endeavors. The LOX mission concept has been proposed to NASA’s astrophysics MIDEX program and will deliver transformational science capabilities to multiple topical areas, all within the envelope of the Explorer Program. LOX directly addresses several findings from both the Astro2010 and Astro2020 Decadal Surveys, including the scientific priority for space-based time-domain multi-messenger capabilities. LOX operations will overlap with new capabilities for discovery such as the Rubin and Roman Telescopes, and gravitational wave and neutrino programs. LOX has significant potential for discovery, will further establish the Moon as a platform for science, and once again pry open a new window on the Cosmos.