Speaker
Description
HII regions are fundamental units of the matter cycle in galaxies and their optical emission serves as the main lens through which we study star formation and chemical enrichment across the Universe. They are the sites where ionising radiation and stellar winds have their main impact, turbulence is injected, and heavy elements are dispersed into the interstellar medium. The sizes and internal structure of HII regions are therefore critical observables to quantify the relative role of different possible pre-supernova feedback mechanisms and provide constraints on the overall stellar feedback energetics to simulations.
In this talk I will present recent results showcasing the spatially resolved structure of HII regions, leveraging the multi-wavelength archive of data of nearby galaxies from the PHANGS survey and observations of Local Group galaxies like M33. I will demonstrate how we are using machine learning to analyse large integral field spectroscopy datasets to detect and classify nebulae. I will then discuss the links between nebulae and their stellar feedback sources. In particular, I will show how the combination of photoionisation modelling and the study of the properties of the ionising stellar sources will enable direct measurements of the escape fraction of ionising photons on cloud scales.
