Measurements of the thermo-chemical evolution of the planet-forming region in disks

Abstract

I will present a large ongoing effort to measure the evolving thermo-chem. structure of planet-forming disks at 0.05-10 au. The main component of this work is high-resoln. spectroscopy (R ∼ 700-100,000) of mol. gas emission at IR wavelengths (2.9-35 um), from a suite of telescopes on the ground and in space (Spitzer, VLT, Keck, IRTF). This technique provides spatial information about mol. gas in inner disk regions unreachable by ALMA. Large surveys of spectrally-resolved IR emission from disks give us measurements of: 1) the location and excitation temp. of CO, H2O, and OH in the 0.05-10 au region, 2) the thermo-chem. evolution of mol. gas, including simple org. mols. (HCN and C2H2), during planet formation, 3) the evolving chem. of inner disks that are being dried-up from water. In addn., we are now combining these surveys to high-resoln. optical spectroscopy, to study the products of mol. photo-dissocn., and to multi-wavelength dust tracers, to characterize the interplay between dust grains and mol. gas in evolving disks. I will conclude with future prospects for mol. inventories in evolving planet-forming disk with JWST.