European
Southern
Observatory

ELT Instruments
METIS
Mid-infrared ELT Imager and Spectrograph

METIS, named after the Greek goddess of wisdom, will be one of the first-generation ELT instruments. It will cover the infrared wavelength range and make full use of the giant, 39-metre main mirror of the telescope to study a wide range of science topics, from objects in our Solar System to distant active galaxies.

In a nutshell

METIS, named after the Greek goddess of wisdom, will be one of the first-generation ELT instruments. It will cover the infrared wavelength range and make full use of the giant, 39-metre main mirror of the telescope to study a wide range of science topics, from objects in our Solar System to distant active galaxies.

Mid-infrared ELT Imager and Spectrograph

METIS, named after the Greek goddess of wisdom, will be one of the first-generation ELT instruments. It will cover the infrared wavelength range and make full use of the giant, 39-metre main mirror of the telescope to study a wide range of science topics, from objects in our Solar System to distant active galaxies.

METIS’s powerful spectrograph and high-contrast imager will allow us to make stunning discoveries near and far and unravel some of the most pressing mysteries about our Universe. In particular, it is expected to make large contributions to one of the most dynamic and exciting fields of astronomy for both scientists and the public — exoplanets. It will allow astronomers to investigate the basic physical and chemical properties of exoplanets, like their orbital parameters and structures, temperature, composition of their atmospheres, weather and seasons. In addition, METIS will contribute to numerous other areas, including the study of the Martian atmosphere, properties of brown dwarfs, the centre of the Milky Way, the environment of evolved stars, and gamma-ray bursts as cosmological probes.  

Science with METIS

How do stars and planets form? How many Earth-sized planets exist around the nearest stars? What lurks at the centre of the Milky Way and galaxies further afield? These are just some of the questions the METIS instrument on the ELT will tackle.

METIS will help astronomers better understand planet formation by investigating the physical structure and evolution of protoplanetary discs, as well as the chemical composition of planet-forming material. The instrument will also allow astronomers to look into already formed planets around other stars, by investigating the climates and atmospheric properties of short- and long-period gas-dominated exoplanets, as well as searching for small planets around the nearest stars. 

In our own Solar System, METIS will allow astronomers to peer through the Martian atmosphere, searching for unknown molecular species in the limb of Mars, which formed at altitudes of 80–100 km under the solar ultraviolet flux. METIS will also study asteroids and Kuiper belt objects, which provide a window into the properties of the protoplanetary disc where Earth and other planets formed. With METIS, astronomers will be able to derive the physical conditions and chemical composition of our planet-formation disc via spectroscopy of asteroids (inner regions) and Kuiper belt objects (outer regions). 

METIS will be extremely well suited to study the life cycle of stars, from infant protostars to older stars near the end of their lifetime. It will further our understanding of the formation of massive stars by investigating accretion processes and disc properties, multiplicities, feedback processes, and luminosity functions in embedded stellar clusters. It will also help astronomers study evolved stars and their circumstellar environments, allowing us to better understand the complex inner wind zone of asymptotic giant branch star envelopes: the velocity, density and thermal structures of the complex envelopes, and their chemistry. METIS is also well suited to study low-mass brown dwarfs ("failed" stars), allowing the search for a possible population of cooler (T < 400 K) brown dwarfs and studies of their rotational velocity. 

In addition, the instrument will allow astronomers to study galaxies and the environments at their centres where black holes lurk. In our own Milky Way, METIS will investigate the immediate vicinity of the galactic black hole, as well as the properties of surrounding young star clusters. METIS will also allow us to do extragalactic science, both at low and high redshift. Looking at closer-by galaxies, it will help us understand the physical origin of the correlation between black hole and galactic spheroid mass from size, geometry, and dynamics of the circumnuclear region, and the interplay between star formation and nuclear feedback. At intermediate redshifts, METIS will study the evolution and merger history of luminous infrared galaxies via the morphology and velocity field of their redshifted Hα emission.

Instrument Design

The instrument consists of two separate units, one for the imager and another one for the spectrograph. It is entirely encased in a cryostat to maintain the stable low temperatures required for good performance at mid-infrared wavelengths.

To achieve diffraction-limited performance, METIS will use a single-conjugate adaptive-optics (AO) system to compensate for atmospheric turbulence. The wavefront will be measured inside METIS, and this information will be used to control the adaptive ELT mirrors (M4 and M5).

Wavelength coverage

3 − 14 μm (imaging); the imager includes low-resolution slit spectroscopy and coronography
3 − 5 μm IFU spectroscopy

Spectral resolution

Low-resolution, long-slit R~400 (N-band), R~1500 (L-band), R~1900 (M-band) 
High-resolution, IFU R~100,000 (L,M bands)

Field-of-view

~10'' (imager), <1'' (high resolution IFU spectroscopy)

AO

all observing modes work at the diffraction limit with a single conjugate AO system

Tools and Documents

Simulator 

Tool to simulate instrument observations  

Science Case 

Description of the scientific motivations for the instrument, as initially submitted by the instrument consortium  

Top Level Requirements

Description of the characteristics of the instrument required by the science

Instrument Consortium and Contacts

METIS is made possible through the collaboration between astronomy institutes in various countries in Europe and overseas. 

The METIS international consortium consists of NOVA (Netherlands Research School for Astronomy represented by the University of Leiden, The Netherlands), the Max Planck Institute for Astronomy (MPIA, based in Heidelberg, Germany), the University of Cologne (Germany), the UK Astronomy Technology Centre (UKATC, in Edinburgh, Scotland, UK), the KULeuven (Belgium), the Paris Saclay research center of the CEA (French Alternative Energies and Atomic Energy Commission, France), Center for Astrophysics and Gravitation (CENTRA, University of Lisbon, Portugal), ETH Zürich (Switzerland), A* (an Austrian partnership represented by the University of Vienna, the University of Innsbruck, the University of Graz, the University of Linz, and RICAM Linz, Austrian Academy of Sciences, Austria), the University of Michigan at Ann Arbor (United States), Academia Sinica Institute of Astronomy and Astrophysics in Taipei (Taiwan), Universite de Liege (Belgium), and with contributions from ESO.

Principal Investigator

Bernhard Brandl (Sterrewacht Leiden, Leiden University, The Netherlands)

Project Scientist

Sascha P. Quanz (ETH Zurich, Switzerland)

Project Manager

Felix Bettonvil (Sterrewacht Leiden, Leiden University, The Netherlands)

ESO Project Manager

Christoph Haupt (ESO)

ESO Project Scientist

Ralf Siebenmorgen (ESO)

ESO Project Engineer

Reinhold Dorn (ESO)