Daniel Kunth
Institut d'Astrophysique de Paris (Paris, France)
with time: HII regions produce Lyman alpha photons and as stellar winds
and SNe are produced a superbubble develops carrying out metals within a
hot gas. The Lyman alpha emission visibility is driven by the physical
state of the the insterstellar medium around these massive star clusters.
Spectroscopic observational evidences of large outflows from GHRS and STIS
data will be presented. The kinematical properties derived from the Ly
alpha line and its spatial decoupling from the UV continuum indicate that
large HI haloes are present in these galaxies. These outflows within such
halos question whether a large fraction of the newly produced metals will
be ultimately ejected from the ISM to the IGM. Moreover these studies of
local starbursts provide additional constraints on the derivation the
cosmic star formation rate and the density of high redshift Ly alpha
emitters. We finally illustrate our results with recent deep Ly alpha
images obtained with the HST-ACS imager. These images reveal the complex
relation between the Ly alpha emission, the UV continuum, the dust
distribution and the HI gas.
Salle Entresol Daniel Chalonge, Institut d'Astrophysique de Paris