Science with an ngVLA: Organics in Disk Midplanes with the ngVLA

TL;DR

The paper discusses how the ngVLA telescope can effectively observe organic molecules in the midplanes of protoplanetary disks, providing insights into planet formation and potential habitability.

Contribution

It demonstrates that ngVLA's sensitivity and wavelength range enable detailed mapping of organic molecules in disk midplanes, overcoming previous observational limitations.

Findings

ngVLA can detect and map organics like CH3CN in nearby disks

Observations penetrate dust opacity in the midplane

Potential to study chemical compositions relevant to planet habitability

Abstract

Planets assemble in the midplanes of protoplanetary disks. The compositions of dust and gas in the disk midplane region determine the compositions of nascent planets, including their chemical hospitality to life. In this context, the distributions of volatile organic material across the planet and comet forming zones is of special interest. These are difficult to access in the disk midplane at IR and even millimeter wavelengths due to dust opacity, which can veil the midplane, low intrinsic molecular abundances due to efficient freeze-out, and, in the case of mid-sized organics, a mismatch between expected excitation temperatures and accessible line upper energy levels. At ngVLA wavelengths, the dust is optically thin, enabling observations into the planet forming disk midplane. ngVLA also has the requisite sensitivity. Using TW Hya as a case study, we show that ngVLA will be able to map out the distributions of diagnostic organics, such as CH3CN, in nearby protoplanetary disks.