# Astro2020 Science White Paper: Dynamical Processes in the Planet-Forming Environment

## TL;DR

This white paper discusses the various dynamical processes such as accretion, jets, and winds that influence planet formation and disk evolution, emphasizing the role of metallic emission lines in probing these phenomena.

## Contribution

It highlights the importance of high-resolution spectral studies of emission lines to understand gas kinematics and mass loss in planet-forming environments.

## Key findings

- Metallic emission lines reveal gas kinematics in disks.
- High-resolution spectroscopy informs on mass and momentum loss.
- Understanding these processes impacts theories of planet formation.

## Abstract

The transfer of circumstellar disk mass and momentum onto the protostar and out into the environment occurs via a variety of mechanisms including magnetospheric accretion, jets, outflows, and disk winds. The interplay of these processes determine both the conditions under which planet formation occurs and the lifetime of the disk. Metallic emission lines, along with the Balmer series of hydrogen, probe the kinematics of gas within the planet-forming and central regions of circumstellar disks. High-spectral resolution study of these emission lines provides critical information on mass and momentum loss, turbulence, and disk wind origins.