The birth and death of organic molecules in protoplanetary disks

TL;DR

This paper reviews the chemical evolution of protoplanetary disks, focusing on the formation and destruction of organic molecules, and compares theoretical predictions with observational data to understand pre-biotic molecule presence during planet formation.

Contribution

It provides a synthesis of current observational and theoretical insights into organic molecule abundance in protoplanetary disks, highlighting the effects of stellar radiation and chemical processing.

Findings

Certain organic molecules like H₂CO may be underabundant in inner disk regions.

High-energy stellar radiation influences chemical composition.

Current models have limitations in predicting molecular abundances.

Abstract

The most intriguing question related to the chemical evolution of protoplanetary disks is the genesis of pre-biotic organic molecules in the planet-forming zone. In this contribution we briefly review current observational knowledge of physical structure and chemical composition of disks and discuss whether organic molecules can be present in large amounts at the verge of planet formation. We predict that some molecules, including CO-bearing species such as H$_2$CO, can be underabundant in inner regions of accreting protoplanetary disks around low-mass stars due to the high-energy stellar radiation and chemical processing on dust grain surfaces. These theoretical predictions are further compared with high-resolution observational data and the limitations of current models are discussed.