Vol. 576
In section 1. Letters

VLT/MUSE view of the highly ionized outflow cones in the nearby starburst ESO338-IG04

by A. Bik, G. Östlin, M. Hayes, et al., A&A 576, L13


It is important to study local analogs of Lyman-break galaxies at high redshift because the resonant nature of the Lyman-alpha line means that interpreting its flux is complex. The starburst galaxy ESO 338-IG04 is such an analog, and its ionized gas has been studied with high resolution with MUSE on the VLT. Young star clusters produce HII regions in the center, and outflows of ionized gas are detected in the H-alpha velocity map. The outflows are associated with highly ionized cones. These outflows allow ionizing photons to escape and help to explain why observed Ly-alpha fluxes are strongly variable: The flux variation depends on the orientation of the galaxies. This also influences how the Ly-alpha escape fraction evolves with redshift.