GPI 2.0: Characterizing Self-Luminous Exoplanets Through Low-Resolution Infrared Spectroscopy

TL;DR

This paper evaluates the GPI 2.0 instrument's capability to characterize self-luminous exoplanets using low-resolution infrared spectra, focusing on constraining temperature and gravity through simulated observations.

Contribution

It models the GPI 2.0 spectrograph and assesses its potential for exoplanet property constraints via spectral analysis, incorporating realistic noise and instrument effects.

Findings

GPI 2.0 can accurately constrain exoplanet temperature.

Gravity remains largely uncertain from the spectra.

Instrument line spread function affects spectral analysis results.

Abstract

Direct imaging characterization of extrasolar planets is often done at low spectral resolution. We model the spectrograph for the Gemini Planet Imager upgrade (GPI 2.0) and assess the instrument's potential for allowing observers to constrain exoplanet properties through analysis of near-infrared spectra. We simulated noisy observations followed by calculations of posterior distributions from maximum likelihood comparison with the Sonora 2018 model grid. Preliminary results suggest that GPI 2.0 should allow observers to constrain temperature with sufficient accuracy, but gravity remains largely uncertain. We also explore the effects of incorporating convolution with the instrument line spread function into our simulation and compare the results with our preliminary findings.