Sensitivity and Performance of LBTI/NOMIC Spectroscopy: Prospects for 10- and 30-meter class Mid-IR Exoplanet Science

TL;DR

This paper evaluates the capabilities of LBTI/NOMIC's low-resolution mid-infrared spectroscopy for exoplanet atmospheric studies, highlighting initial testing, challenges, and future prospects for 8-13 μm observations.

Contribution

It provides the first characterization and commissioning of NOMIC's spectroscopic mode, analyzing observational strategies and detector limitations for future high-resolution exoplanet spectroscopy.

Findings

Initial on-sky testing with standard stars and binaries conducted.

Impact of observational strategies and telluric calibration analyzed.

Discussion on detector limitations and requirements for future high-resolution spectroscopy.

Abstract

Long wavelength infrared (8-13 $\mu$m) spectroscopy is invaluable for detecting molecular features in the atmospheres of gas giant and terrestrial exoplanets. The nulling-optimized mid-infrared camera (NOMIC) on the Large Binocular Telescope Interferometer (LBTI) has a low resolution (R$\sim$200) germanium grism that was previously installed but has not been characterized and commissioned for scientific observations. Using a 1.27 mm slit and broadband filter in combination with the grism, the infrared window between 8-13 $\mu$m can be captured. We describe initial on sky testing of the LBTI/NOMIC grism mode with adaptive optics to study standard stars and binaries. We discuss the impact of observational strategy and telluric calibration on the spectral reduction process. We infer the impact of existing mid-infrared detectors on NOMIC's spectroscopic mode and discuss requirements to enable higher resolution 8-13 $\mu$m spectroscopy on current and future facilities.