TY - JOUR
T1 - Asgard/NOTT: L-band nulling interferometry at the VLTI
T2 - I. Simulating the expected high-contrast performance
AU - Laugier, Romain
AU - Defrère, Denis
AU - Woillez, Julien
AU - Courtney-Barrer, Benjamin
AU - Dannert, Felix A.
AU - Matter, Alexis
AU - Dandumont, Colin
AU - Gross, Simon
AU - Absil, Olivier
AU - Bigioli, Azzurra
AU - Garreau, Germain
AU - Labadie, Lucas
AU - Loicq, Jérôme
AU - Martinod, Marc-Antoine
AU - Mazzoli, Alexandra
AU - Raskin, Gert
AU - Sanny, Ahmed
N1 - Copyright © 2023 The Authors. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.
PY - 2023/3/1
Y1 - 2023/3/1
N2 - Context. NOTT (formerly Hi-5) is a new high-contrast L′ band (3.5-4.0 μm) beam combiner for the VLTI designed with an ambitious aim to be sensitive to young giant exoplanets down to 5 mas separation around nearby stars. The performance of nulling interferometers in these wavelengths is affected both by fundamental noise from the background and contributions of instrumental noise. This motivates the development of end-to-end simulations to optimize these instruments.Aims. The aim of this study is to enable a performance evaluation of NOTT and inform the design of such instruments with current and future infrastructures in mind, taking into account the different sources of noise and their correlation.Methods. SCIFYsim is an end-to-end simulator for single-mode-filtered beam combiners, with an emphasis on nulling interferometers. We use it to compute a covariance matrix of the errors. We then use statistical detection tests based on likelihood ratios to compute compound detection limits for the instrument.Results. With the current assumptions as to the performance of the wavefront correction systems, the errors are dominated by correlated instrumental errors down to stars of magnitude 6-7 in the L band, beyond which thermal background from the telescopes and relay system becomes dominant.Conclusions. SCIFYsim is suited to anticipating some of the challenges of design, tuning, operation, and signal processing for integrated-optics beam combiners. The detection limits found for this early version of NOTT simulation with the unit telescopes are compatible with detections at contrasts up to 105 in the L band at separations of 5-80 mas around bright stars.
AB - Context. NOTT (formerly Hi-5) is a new high-contrast L′ band (3.5-4.0 μm) beam combiner for the VLTI designed with an ambitious aim to be sensitive to young giant exoplanets down to 5 mas separation around nearby stars. The performance of nulling interferometers in these wavelengths is affected both by fundamental noise from the background and contributions of instrumental noise. This motivates the development of end-to-end simulations to optimize these instruments.Aims. The aim of this study is to enable a performance evaluation of NOTT and inform the design of such instruments with current and future infrastructures in mind, taking into account the different sources of noise and their correlation.Methods. SCIFYsim is an end-to-end simulator for single-mode-filtered beam combiners, with an emphasis on nulling interferometers. We use it to compute a covariance matrix of the errors. We then use statistical detection tests based on likelihood ratios to compute compound detection limits for the instrument.Results. With the current assumptions as to the performance of the wavefront correction systems, the errors are dominated by correlated instrumental errors down to stars of magnitude 6-7 in the L band, beyond which thermal background from the telescopes and relay system becomes dominant.Conclusions. SCIFYsim is suited to anticipating some of the challenges of design, tuning, operation, and signal processing for integrated-optics beam combiners. The detection limits found for this early version of NOTT simulation with the unit telescopes are compatible with detections at contrasts up to 105 in the L band at separations of 5-80 mas around bright stars.
KW - Methods: data analysis
KW - Methods: statistical
KW - Techniques: high angular resolution
KW - Techniques: interferometric
UR - http://www.scopus.com/inward/record.url?scp=85150212098&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202244351
DO - 10.1051/0004-6361/202244351
M3 - Article
AN - SCOPUS:85150212098
SN - 0004-6361
VL - 671
SP - 1
EP - 14
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A110
ER -