Large Interferometer For Exoplanets (LIFE): I. Improved exoplanet detection yield estimates for a large mid-infrared space-interferometer mission
Journal article, 2022
Context. One of the long-term goals of exoplanet science is the atmospheric characterization of dozens of small exoplanets in order to understand their diversity and search for habitable worlds and potential biosignatures. Achieving this goal requires a space mission of sufficient scale that can spatially separate the signals from exoplanets and their host stars and thus directly scrutinize the exoplanets and their atmospheres. Aims. We seek to quantify the exoplanet detection performance of a space-based mid-infrared (MIR) nulling interferometer that measures the thermal emission of exoplanets. We study the impact of various parameters and compare the performance with that of large single-aperture mission concepts that detect exoplanets in reflected light. Methods. We have developed an instrument simulator that considers all major astrophysical noise sources and coupled it with Monte Carlo simulations of a synthetic exoplanet population around main-sequence stars within 20 pc of the Sun. This allows us to quantify the number (and types) of exoplanets that our mission concept could detect. Considering single visits only, we discuss two different scenarios for distributing 2.5 yr of an initial search phase among the stellar targets. Different apertures sizes and wavelength ranges are investigated. Results. An interferometer consisting of four 2 m apertures working in the 4'18.5 m wavelength range with a total instrument throughput of 5% could detect up to 550 exoplanets with radii between 0.5 and 6 R-with an integrated S=N 7. At least-160 of the detected exoplanets have radii 1.5 R-. Depending on the observing scenario 25'45 rocky exoplanets (objects with radii between 0.5 and 1.5 R-) orbiting within the empirical habitable zone (eHZ) of their host stars are among the detections. With four 3.5 m apertures, the total number of detections can increase to up to 770, including-60'80 rocky eHZ planets. With four times 1 m apertures, the maximum detection yield is-315 exoplanets, including-20 rocky eHZ planets. The vast majority of small, temperate exoplanets are detected around M dwarfs. The impact of changing the wavelength range to 3'20-m or 6'17-m on the detection yield is negligible. Conclusions. A large space-based MIR nulling interferometer will be able to directly detect hundreds of small, nearby exoplanets, tens of which would be habitable world candidates. This shows that such a mission can compete with large single-aperture reflected light missions. Further increasing the number of habitable world candidates, in particular around solar-type stars, appears possible via the implementation of a multi-visit strategy during the search phase. The high median S/N of most of the detected planets will allow for first estimates of their radii and effective temperatures and will help prioritize the targets for a second mission phase to obtain high-S/N thermal emission spectra, leveraging the superior diagnostic power of the MIR regime compared to shorter wavelengths.
Instrumentation: high angular resolution
Planets and satellites: detection
Methods: numerical
Infrared: planetary systems
Telescopes
Planets and satellites: terrestrial planets
Author
S. P. Quanz
National Center of Competence in Research PlanetS
Swiss Federal Institute of Technology in Zürich (ETH)
M. Ottiger
Swiss Federal Institute of Technology in Zürich (ETH)
E. Fontanet
Swiss Federal Institute of Technology in Zürich (ETH)
J. Kammerer
European Southern Observatory (ESO)
Australian National University
Space Telescope Science Institute (STScI)
University of Delhi
F. Menti
Swiss Federal Institute of Technology in Zürich (ETH)
F. Dannert
Swiss Federal Institute of Technology in Zürich (ETH)
A. Gheorghe
Swiss Federal Institute of Technology in Zürich (ETH)
O. Absil
University of Liège
V. S. Airapetian
National Aeronautics and Space Administration (NASA)
E. Alei
National Center of Competence in Research PlanetS
Swiss Federal Institute of Technology in Zürich (ETH)
R. Allart
Université de Montréal
D. Angerhausen
National Center of Competence in Research PlanetS
Swiss Federal Institute of Technology in Zürich (ETH)
S. Blumenthal
University of Oxford
L. A. Buchhave
Technical University of Denmark (DTU)
J. Cabrera
German Aerospace Center (DLR)
Carrión-González
Technische Universität Berlin
G. Chauvin
Grenoble Alpes University
W. Danchi
National Aeronautics and Space Administration (NASA)
C. Dandumont
University of Liège
D. Defrere
KU Leuven
C. Dorn
University of Zürich
D. Ehrenreich
University of Geneva
S. Ertel
University of Arizona
Large Binocular Telescope Observatory
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Leiden University
A. García Muñoz
Technische Universität Berlin
C. Gascón
Spanish National Research Council (CSIC)
J. H. Girard
Space Telescope Science Institute (STScI)
A. M. Glauser
Swiss Federal Institute of Technology in Zürich (ETH)
J. L. Grenfell
German Aerospace Center (DLR)
G. Guidi
National Center of Competence in Research PlanetS
Swiss Federal Institute of Technology in Zürich (ETH)
J. Hagelberg
University of Geneva
R. Helled
University of Zürich
Michael Ireland
Australian National University
University of Delhi
Markus Janson
Stockholm University
R. K. Kopparapu
National Aeronautics and Space Administration (NASA)
Judith Korth
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
T. Kozakis
Technical University of Denmark (DTU)
S. Kraus
University of Exeter
A. Léger
Institut d'Astrophysique Spatiale
L. Leedjärv
University of Tartu
T. Lichtenberg
University of Oxford
J. Lillo-Box
Centro de Astrobiologia (CAB)
H. Linz
Max Planck Society
René Liseau
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
J. Loicq
University of Liège
V. Mahendra
SRM Institute of Science and Technology
F. Malbet
Grenoble Alpes University
J. Mathew
Australian National University
University of Delhi
B. Mennesson
Jet Propulsion Laboratory, California Institute of Technology
M. Meyer
University of Michigan
L. Mishra
University of Bern
University of Geneva
National Center of Competence in Research PlanetS
K. Molaverdikhani
Max Planck Society
Heidelberg-Königstuhl State Observatory
L. Noack
Freie Universität Berlin
A. V. Oza
Jet Propulsion Laboratory, California Institute of Technology
University of Bern
Enric Palle
Instituto de Astrofísica de Canarias
University of La Laguna
H. Parviainen
University of La Laguna
Instituto de Astrofísica de Canarias
A. Quirrenbach
Heidelberg-Königstuhl State Observatory
H. Rauer
German Aerospace Center (DLR)
I. Ribas
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
Spanish National Research Council (CSIC)
M. Rice
Yale University
A. Romagnolo
Polish Academy of Sciences
S. Rugheimer
University of Oxford
E. W. Schwieterman
University of California
E. Serabyn
Jet Propulsion Laboratory, California Institute of Technology
S. Sharma
Vanderbilt University
Keivan G. Stassun
University of Cambridge
J. Szulágyi
Swiss Federal Institute of Technology in Zürich (ETH)
H. S. Wang
National Center of Competence in Research PlanetS
Swiss Federal Institute of Technology in Zürich (ETH)
F. Wunderlich
German Aerospace Center (DLR)
M. Wyatt
Swiss Federal Institute of Technology in Zürich (ETH)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 664 A21Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Other Physics Topics
Signal Processing
DOI
10.1051/0004-6361/202140366