# Astro2020 Science White Paper: Making the Connection between Feedback andSpatially Resolved Emission Line Diagnostics

## TL;DR

Advancing our understanding of star formation and feedback requires high-resolution, spatially resolved spectroscopic observations of extit{H}{ extsc{ii}} regions across entire galaxies to measure physical conditions and their evolution.

## Contribution

This white paper emphasizes the need for high spatial resolution and deep sensitivity in spectroscopic observations to better understand star formation feedback processes.

## Key findings

- Spatially resolved spectroscopy is crucial for understanding extit{H}{ extsc{ii}} regions.
- Current limitations hinder full galactic coverage of extit{H}{ extsc{ii}} regions.
- Improved observations will help disentangle physical processes in star formation.

## Abstract

Crucial progress in our understanding of star formation and feedback will depend on the ability to obtain spatially resolved spectroscopic observations of \ion{H}{ii} regions, from which reliable instantaneous measurements of their physical conditions can be obtained. Acquiring these datasets across full galactic systems will prove crucial for obtaining population samples that enable us to understand the time evolution of similar regions, and the variability of conditions among coeval regions. Separating the spatial and temporal dependencies in such way for different physical processes involved in star formation and the injection of feedback is crucial to overcome the inherit degeneracies associated with observing instantaneous snapshots of a dynamic ISM at any given time. Emission line diagnostics are at the core of measuring the physical condition in \ion{H}{ii} regions (e.g. dynamics, SFR, chemical abundances, dust extinction, ionization and excitation, etc.). These measurements require high spatial resolution, contiguous coverage across full galactic systems, and sensitivities significantly deeper than past efforts. The spatial scale required to resolve the \ion{H}{ii} regions of a few pc is only attainable in the Local Group where very large sky coverage is necessary.