The Lyman-alpha emission in local Star-Forming Galaxies: Scenario and Connection with Primeval Galaxies

Abstract

We review the Lyff emission in local star-forming galaxies. In most cases as already shown by the IUE, the emission is absent or much weaker than expected. This occurs because Lyff photons can be resonantly scattered by the neutral gas and destroyed by even very low amounts of dust. However new Hubble Space Telescope observations (HST) indicate that other factors such as the velocity structure of the gas play a crucial role. Gas flows are likely to occur as powered by the kinetic energy released via stellar winds and supernova. We propose a scenario based on the hydrodynamics of superbubbles powered by massive bursts of star formation that naturally accounts for the variety of Lyff line detections in star-forming galaxies. We caution with the attempts to derive the co-moving star formation rate at high redshift from Lyff emission searches. 1 Introduction The search for high-redshift galaxies have progressed rapidly over the last ten years using color techniques which basically select ...