Dust Eddington Ratios for Star-Forming Galaxy Subregions

Understand

Radiation pressure on dust is an important feedback process around star clusters and may eject gas from bright sub-regions in star-forming galaxies.

• The Eddington ratio has previously been constructed for galaxy-averaged observations, individual star clusters, and Galactic HII regions.
• Here we assess the role of radiation pressure in thousands of sub-regions across two local star-forming galaxies, NGC 6946 and NGC 5194.
• Using a model for the spectral energy distribution from stellar population synthesis and realistic dust grain scattering and absorption, we compute flux- and radiation pressure-mean opacities and population-averaged optical depth $\langle\tau_{\rm RP}\rangle$.