Objectif It is proposed to study the properties of massive (Wolf-Rayet, OB) star populations in blue compact galaxies with a heavy element mass fraction Z < 1/10 Zsun, and their interaction with the interstellar medium. A systematic search for Wolf-Rayet galaxies with very low metallicities based on existing spectroscopic data and future observations on large telescopes (Russia, Europe, USA) will be undertaken. These observations will be used in conjuction with state-of-the-art models for the spectral and interior evolution of massive stars and integrated population as well as multiphase multizone chemical evolution models to analyse the massive star content in these objects, to derive the burst properties (age, initial mass function), and to study the properties (excitation, dynamics, composition) of the ionised interstellar medium.This allows to draw a consistent picture of the massive star content and the ionised interstellar gas in extremely metal-poor blue compact galaxies which will be used to the following aims:- Derive constraints on the evolution of massive stars at very low metallicities;- Study the nature of nebular Helium II emission in these objects;- Analyse the chemical composition and inhomogeneities in HII regions and the impact of Wolf-Rayet stars on the interstellar medium;- Study the chemical evolution of oxygen and the role of outflows in blue compact galaxies.These studies have direct implications on the knowledge of massive stars, their interactions with the interstellar medium, and the chemical evolution of compact galaxies in the early universe. Programme(s) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Thème(s) 1A - Nuclear Physics, Astronomy, Astrophysics INTAS - INTAS Appel à propositions Data not available Régime de financement Data not available Coordinateur Observatoire Midi-Pyrenees Contribution de l’UE Aucune donnée Adresse 14, Avenue E. Belin 31400 Toulouse France Voir sur la carte Coût total Aucune donnée Participants (4) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire National Academy of Sciences of Ukraine Ukraine Contribution de l’UE Aucune donnée Adresse Golosiiv 250650 Kiev Voir sur la carte Coût total Aucune donnée Observatoire de Geneve Suisse Contribution de l’UE Aucune donnée Adresse Chemin des Maillettes 51 1290 Sauverny Voir sur la carte Coût total Aucune donnée Russian Academy of Sciences Russie Contribution de l’UE Aucune donnée Adresse Zelench Ukskaya 357147 Nizhnij Arkhyz Voir sur la carte Coût total Aucune donnée Universita' di Pisa Italie Contribution de l’UE Aucune donnée Adresse Piazza Torricelli, 2 56100 Pisa Voir sur la carte Coût total Aucune donnée