L-band nulling interferometry at the VLTI with Asgard/NOTT: status and plans

• Main Authors: Defrère, Denis, Laugier, Romain, Martinod, Marc-Antoine, Garreau, Germain, Missiaen, Kwinten, Salman, Muhammad, Raskin, Gert, Dandumont, Colin, Ertel, Steve, Ireland, Michael J, Kraus, Stefan, Labadie, Lucas, Mazzoli, Alexandra, Medgyesi, Gyorgy, Sanny, Ahmed, Absil, Olivier, Ábráham, Peter, Berger, Jean-Philippe, Bonduelle, Myriam, Bigioli, Azzurra, Bouzerand, Emilie, Carter, Josh, Cvetojevic, Nick, Courtney-Barrer, Benjamin, Glauser, Adrian M, Gross, Simon, Haubois, Xavier, James, Noel, Joo, Andras Peter, Lagarde, Stephane, Léger, Alain, Leisenring, Jarron, Loicq, Jérôme, Martin, Guillermo, Martinache, Frantz, Mezo, Gyorgy, Morel, Sébastien, Morren, Johan, Ollivier, Marc, Robertson, Gordon, Rousseau, Hélène, Schofield, Warrick, Schuhler, Nicolas, Taras, Adam, Vandenbussche, Bart, Woillez, Julien
• Format: Journal Article
• Language: English
• Published: 11-07-2024
• Subjects: Physics - Earth and Planetary Astrophysics; Physics - Instrumentation and Methods for Astrophysics
• DOI: 10.48550/arxiv.2407.08397

NOTT (formerly Hi-5) is the L'-band (3.5-4.0~microns) nulling interferometer
of Asgard, an instrument suite in preparation for the VLTI visitor focus. The
primary scientific objectives of NOTT include characterizing (i) young
planetary systems near the snow line, a critical region for giant planet
formation, and (ii) nearby main-sequence stars close to the habitable zone,
with a focus on detecting exozodiacal dust that could obscure Earth-like
planets. In 2023-2024, the final warm optics have been procured and assembled
in a new laboratory at KU Leuven. First fringes and null measurements were
obtained using a Gallium Lanthanum Sulfide (GLS) photonic chip that was also
tested at cryogenic temperatures. In this paper, we present an overall update
of the NOTT project with a particular focus on the cold mechanical design, the
first results in the laboratory with the final NOTT warm optics, and the
ongoing Asgard integration activities. We also report on other ongoing
activities such as the characterization of the photonic chip (GLS, LiNbO3,
SiO), the development of the exoplanet science case, the design of the
dispersion control module, and the progress with the self-calibration data
reduction software.