Séminaire IPAG

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The spectacular environment of dying stars : clues to solve the galaxies dust excess ?

jeudi 14 octobre 2021 - 11h00

Anthony Soulain - IPAG
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Massive stars are one of the major contributors to the enrichment of galaxies in interstellar dust. The ultimate stage called Wolf-Rayet stars is at the origin of one of the most prominent dust production rates (DPR), equivalent to a planet like Mars generated every year. Dusty WR stars could accordingly answer a well-known problem : where does the dust observed in galaxies come from ? To address this important question, we present an extensive observation campaign on the prototype WR104. From the large scale with VLT/VISIR to study the link with the interstellar medium, to the internal regions with VLTI/MATISSE to probe the dust nucleation zone, and the intermediate scale to look at the pinwheel morphology with the AO system VLT/SPHERE. We then present the mid-infrared observation of the Apep system, exhibiting an anisotropic stellar wind, new and unexpected for such object. To discuss the physical sense of our observation, we developed a 3D RAMSES hydrodynamical simulation of the colliding binary embedded in the system’s core. Based on this simulation, we found different regimes of dust production efficiency, resulting in different morphology of the plume. This effort gives a novel clue to probe the physical processes ongoing to generate this unique spiral appearance. By coupling with the radiative transfer code RADMC3d, we described the dust chemistry and constrained the nucleation radius, particularly important for our VLTI observations. Finally, we present the future possibilities of the famous JWST facility and the unique interferometric mode AMI-NIRISS in the context of our ERS program on WR140.

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Hôtes : Benoît Cerutti

Salle Manuel Forestini, 414 rue de la piscine, 38400 Saint Martin d'Hères