Simulating the Exoplanet Yield of a Space-based MIR Interferometer Based on Kepler Statistics

TL;DR

This study predicts the exoplanet detection capabilities of a space-based mid-infrared interferometer using Monte Carlo simulations based on Kepler data, estimating the number and properties of detectable planets.

Contribution

It introduces a detailed simulation framework for predicting exoplanet yields of a MIR interferometer, incorporating technical assumptions and planet population uncertainties.

Findings

Approximately 315 exoplanets detectable in at least one band.

About 85 potentially habitable planets identified as prime spectroscopic targets.

Discovery phase estimated to last 2-3 years considering various observational factors.

Abstract

Aims: We predict the exoplanet yield of a space-based mid-infrared nulling interferometer using Monte Carlo simulations. We quantify the number and properties of detectable exoplanets and identify those target stars that have the highest or most complete detection rate. We investigate how changes in the underlying technical assumptions and uncertainties in the underlying planet population impact the scientific return. Methods: We simulated $2'000$ exoplanetary systems, based on planet occurrence statistics from Kepler with randomly orientated orbits and uniformly distributed albedos around each of $326$ nearby ($d < 20~\text{pc}$) stars. Assuming thermal equilibrium and blackbody emission, together with the limiting spatial resolution and sensitivity of our simulated instrument in the three specific bands $5.6$, $10.0$, and $15.0~\mu\text{m}$, we quantified the number of detectable exoplanets as a function of their radii and equilibrium temperatures. Results: Approximately $\sim315_{-77}^{+113}$ exoplanets, with radii $0.5~R_\text{Earth} \leq R_\text{p} \leq 6~R_\text{Earth}$, were detected in at least one band and half were detected in all three bands during $\sim0.52$ years of mission time assuming throughputs $3.5$ times worse than those for the James Webb Space Telescope and $\sim40\%$ overheads. Accounting for stellar leakage and (unknown) exozodiacal light, the discovery phase of the mission very likely requires $2$ - $3$ years in total. Roughly $85$ planets could be habitable ($0.5~R_\text{Earth} \leq R_\text{p} \leq 1.75~R_\text{Earth}$ and $200~\text{K} \leq T_\text{eq} \leq 450~\text{K}$) and are prime targets for spectroscopic observations in a second mission phase.