Exploring the Solar System beyond Neptune with the ESO/Extremely Large Telescope HARMONI Integral Field Spectrograph

The European Southern Observatory (ESO) 39m-Extremely Large Telescope will be on sky before the end of this decade, and will enable unprecedented spatially resolved observations. HARMONI (High Angular Resolution Monolithic Optical and Near-Infrared Integral field spectrograph) is a first-light instrument that covers the 0.47-2.45 micron range with a spectral resolution R of 3300-18000. Four Fields of View (FOV) sizes are available with "spaxels" scales from 30x60 down to 4x4  milli-arcsecond (mas). HARMONI will operate in two Adaptive Optics (AO) modes: single conjugate adaptive optics (SCAO) and laser tomography adaptive optics (LTAO). In this work, we explore the performances of the near infrared gratings (0.8-2.4 microns, R=3300) in LTAO mode to obtain the surface reflectance spectra of Trans-Neptunian Objects of various apparent diameters and of various surface compositions. We use a complete set of image rendering tools and laboratory data as well as the HSIM simulation pipeline (Zieleniewski et al 2015, MNRAS 453, Issue 4, 3754, which was further enhanced by M. Pereira-Santaella) to produce the observed data cubes. We present the resulting simulations and related performances for the exploration of the very first surface composition constrast maps of dwarf planets beyond Neptune.