Design study and first performance simulation of the ELT/MICADO focal plane coronagraphs

TL;DR

This paper details the design and initial performance simulation of a Lyot coronagraph for MICADO on the ELT, aiming to enhance high-contrast imaging for exoplanet detection and characterization.

Contribution

It presents the design process, mask selection, and realistic performance simulations of the coronagraph for MICADO, including AO residuals and atmospheric effects.

Findings

Simulated contrast improvements with MICADO over current 10-m class telescopes.

Potential to image young giant exoplanets at very short separations.

Enhanced angular resolution for exoplanet detection in the near-infrared.

Abstract

In this paper, we present the design and the expected performance of the classical Lyot coronagraph for the high contrast imaging modes of the wide-field imager MICADO. MICADO is a near-IR camera for the Extremely Large Telescope (ELT, previously E-ELT), with wide-field, spectroscopic and coronagraphic capabilities. MICADO is one of the first-light instruments selected by the ESO. Optimized to work with a multi-conjugate adaptive optics corrections provided by the MOARY module, it will also come with a SCAO correction with a high-level, on-axis correction, making use of the M4 adaptive mirror of the telescope. After presenting the context of the high contrast imaging modes in MICADO, we describe the selection process for the focal plane masks and Lyot stop. We will also show results obtained in realistic conditions, taking into account AO residuals, atmospheric refraction, noise sources and simulating observations in angular differential imaging (ADI) mode. Based on SPHERE on-sky results, we will discuss the achievable gain in contrast and angular separation provided by MICADO over the current instruments on 10-m class telescopes, in particular for imaging young giant planets at very short separations around nearby stars as well as planets on wider orbits around more distant stars in young stellar associations.