MICADO will also be well suited to investigating the region surrounding the black hole at the centre of the Milky Way, furthering the work conducted with ESO telescopes since the 1990s that was recognised with the 2020 Nobel Prize in Physics. Astronomers have discovered that there are massive black holes at the centre of many galaxies, and our Galactic home is no exception. A black hole with a mass four million times that of the Sun has been detected by observing its impact on the orbits of nearby stars. Over the past decades, using the highest spatial resolution imagers, astronomers have mapped the motions of these stars with great precision down to a distance of just 25 light days — or 648 billion kilometres — from the central black hole. MICADO will be able to take us even closer: to within five light-days.

It is not just the instrument's high spatial resolution that will enable such research, but also the fact that it is sensitive to infrared wavelengths that can penetrate the dust that shrouds the centre of the Milky Way. These observations will allow astronomers to test the theory of general relativity thanks to the extreme gravitational forces present at the Galactic Centre.

Light from the telescope will enter the top of the MICADO housing. In SCAO mode, light at visible wavelengths will be selected and directed to a wavefront sensor. The real time computer will calculate the corrections to be applied to the ELT's adaptive mirror (M4) to provide a sharp image. In MCAO mode, the beam will pass into the wavefront sensing module. Three stars needed to provide signals to the telescope M4 and the two additional deformable mirrors in MORFEO are selected by pick-off mirrors from a patrol field outside the scientific field of view of MICADO. 

The near-infrared part of the beam will always pass into the cryostat. The infrared beam will then be collimated, filtered depending on the wavelength requirements of the astronomical observations being carried out, and passed through one of four exchangeable sets of optical components. The optics required to provide the MICADO narrow-field mode will be fixed; by rotating the Main Selection Mechanism wheel, the astronomer may choose between the wide-field mode optics or the spectrograph optics (including the dispersion gratings). There will also be a set of pupil-viewing optics for testing and checking that MICADO remains aligned with the telescope. Finally, an image of the astronomical field being observed will be formed on a 3 x 3 array of near-infrared sensitive detectors. Each of the nine state-of-the-art detectors will have 4096 x 4096 pixels, each pixel 15 μm x 15 μm in size. 

Simulator

Tool to simulate instrument observations

Top Level Requirements

Description of the characteristics of the instrument required by the science case

The MICADO project is managed by an international consortium composed of research institutes from six different countries.

MICADO is being designed and built under the leadership of the Max Planck Institute for Extraterrestrial Physics (MPE) by a consortium of partners in Finland, Germany, France, the Netherlands, Austria and Italy, together with ESO. In addition to MPE, the MICADO consortium consists of the Max Planck Institute for Astronomy (Germany), the University Observatory Munich (Germany), the Institute for Astrophysics in Göttingen (Germany), NOVA (Netherlands Research School for Astronomy, represented by the University of Groningen, the University of Leiden, and the NOVA optical/infrared instrumentation group based at ASTRON), INAF, CNRS/INSU (the National institute For Earth Science and Astronomy of the French National Centre for Scientific Research, represented by the LESIA Space and Astrophysics Instrumentation Research Laboratory at Paris Observatory, the GEPI Galaxies, Stars, Physics and Instrumentation Laboratory at Paris Observatory, the UTINAM Universe, Time-Frequency, Interfaces, Nanostructures, Atmosphere-Environment and Molecules Institute, the LCF Charles Fabry Laboratory at Institut d’Optique Graduate School, and the IP2I Institute of Physics of 2 Infinites), A* (an Austrian partnership represented by the University of Vienna, the University of Innsbruck, the University of Linz, the Johann Radon Institute for Computational and Applied Mathematics at the University of Linz, and the Austrian Academy of Sciences), FINCA (the Finnish Centre for Astronomy with ESO), and the University of Turku (Finland).