ANDES

Uppsala astronomers are contributing to the development of a high-resolution spectrometer for the European Extremely Large Telescope (E-ELT). With a massive 39-meter light-collecting area, this telescope will enable the study of faint and distant objects in particular detail. The first scientific observations are expected to begin in 2027, marking a new era in astronomical observations.

Spectroscopy, a method crucial for determining temperatures, densities, and chemical compositions of celestial bodies, will be a key tool in examining any astronomical targets. One of the first instruments planned for the ELT is the optical-infrared high-resolution spectrograph known as ANDES (ArmazoNes high Dispersion Echelle Spectrograph), previously referred to as ELT-HIRES. ANDES will operate under both seeing- and diffraction-limited conditions, with a flexible fiber-feeding system that allows for multiple observing modes. These include a single conjugated adaptive optics module and a small diffraction-limited integral field unit in the near-infrared.

ANDES has a broad range of exciting science objectives, spanning nearly all areas of astrophysics and even fundamental physics. Key research goals include detecting biosignatures in exoplanet atmospheres, identifying the remnants of the first generation of stars, testing any previously derived fundamental constants, and directly detecting cosmic acceleration. The ANDES project is backed by a large international consortium, consisting of 35 institutes from 13 countries, with nearly 300 scientists and engineers contributing their expertise from across ESO member states.

In 2020, the consortium completed a Phase A study, confirming the feasibility of designing and building this advanced spectrograph. The study verified that ANDES will cover a spectral range from 0.4 to 1.5 microns with a spectral resolution of 3 km/s. The spectrograph will be composed of several specialized arms, each optimized for a specific part of the visible and near-infrared spectrum. ESO has approved the instrument for Phase B, which is currently in progress.

For more details, visit the official ANDES page on the ESO website: https://elt.eso.org/instrument/ANDES/.