An optimised survey strategy for the ERIS/NIX imager: searching for young giant exoplanets and very low mass brown dwarfs using the K-peak custom photometric filter

TL;DR

This paper proposes optimized survey strategies for the NIX imager on VLT, using a custom K-peak filter to enhance detection of young giant exoplanets and brown dwarfs, informed by previous survey data and population models.

Contribution

It introduces four novel approaches to target selection for maximizing detection yield in direct imaging surveys with the NIX instrument.

Findings

Optimized target selection strategies increase detection probability.

NIX performance surpasses other state-of-the-art instruments in simulations.

Four distinct survey approaches are proposed for different target types.

Abstract

We present optimal survey strategies for the upcoming NIX imager, part of the ERIS instrument to be installed on the Very Large Telescope (VLT). We will use a custom 2.2 micron K-peak filter to optimise the efficiency of a future large-scale direct imaging survey, aiming to detect brown dwarfs and giant planets around nearby stars. We use the results of previous large scale imaging surveys (primarily SPHERE SHINE and Gemini GPIES) to inform our choice of targets, as well as improved planet population distributions. We present four possible approaches to optimise survey target lists for the highest yield of detections: i) targeting objects with anomalous proper motion trends, ii) a follow-up survey of dense fields from SPHERE SHINE and Gemini GPIES iii) surveying nearby star-forming regions and iv) targeting newly discovered members of nearby young moving groups. We also compare the predicted performance of NIX to other state-of-the-art direct imaging instruments.